Citation

Mashrafi, M. (2026). Twin-Arch Crown High-Rise Towers: Geometry-Driven Structural Stability and Passive Environmental Performance in Coastal Urban Contexts. Journal for Studies in Management and Planning, 11(12), 58–78. https://doi.org/10.26643/jsmap/6

:
Mokhdum Mashrafi (Mehadi Laja)     

Email: mehadilaja311@gmail.com

Research Associate, Track2Training, India

Researcher from Bangladesh

Abstract

High-rise development in coastal urban environments is governed by the combined challenges of gravity-induced structural demand, wind-generated dynamic response, torsional instability, and elevated operational energy consumption driven by harsh climatic exposure. This study proposes a twin-arch crown high-rise tower system consisting of two vertically curved towers interconnected through a shared podium and arch-like crown geometry. The configuration is analytically examined as a geometry-driven structural and environmental system, in which architectural form actively participates in load redistribution, aerodynamic moderation, and passive climate control.

Symbolic structural models demonstrate that the curved twin-tower and arch configuration redirects a substantial portion of gravity and lateral wind forces into axial compression–dominant load paths, reducing bending demand and improving global stiffness relative to conventional cantilevered tower forms. Dynamic analysis indicates that geometric coupling between the towers increases effective lateral stiffness by approximately 15–30%, resulting in upward shifts of fundamental natural frequencies and associated 20–40% reductions in peak wind-induced acceleration, enhancing occupant comfort under coastal wind spectra. Structural symmetry and shared load paths significantly reduce mass–stiffness eccentricity, leading to marked suppression of torsional response.

The perimeter curved shell functions as a partial exoskeletal load-sharing system, carrying an estimated 30–45% of combined gravity and lateral loads, thereby improving redundancy, robustness, and resilience without proportional increases in material usage. Environmental performance analysis shows that the curved façades and inter-tower spacing generate favorable pressure differentials, increasing wind-driven natural ventilation rates by 25–50% compared to flat-faced high-rise typologies. Solar–thermal modeling further indicates that curvature-induced modulation of incident angles can reduce peak façade solar heat gain by 20–35%, lowering cooling demand in tropical and subtropical coastal climates.

The findings demonstrate that architectural geometry, when systematically aligned with structural mechanics and environmental physics, can function as an integrated performance system rather than a purely aesthetic device. The proposed framework is scalable, analytically transparent, and compatible with established performance-based design, CFD simulation, and wind-tunnel validation methods. As such, it provides a scientifically robust and adaptable model for sustainable, climate-responsive landmark development in contemporary and future coastal metropolitan regions.

Keywords: twin towers, shell structures, exoskeleton systems, wind-resistant high-rise, passive environmental design

1. Introduction

Rapid urbanization in coastal metropolitan regions has intensified the demand for high-rise buildings capable of addressing structural stability, aerodynamic performance, and environmental sustainability simultaneously. Conventional high-rise systems, typically based on vertical cantilever action and rectilinear geometries, are often inefficient in resisting wind-induced forces and require significant material usage and mechanical energy consumption (Kareem & Tamura, 2007; Holmes, 2015).

Recent advancements in tall-building design emphasize the role of geometry as a primary determinant of structural and environmental performance. Curved and aerodynamically optimized forms have been shown to reduce vortex shedding, minimize wind-induced acceleration, and enhance serviceability (Irwin, 2009). Additionally, perimeter-based structural systems, including exoskeletons and shell structures, improve stiffness and redistribute loads through axial force paths rather than bending (Allen & Zalewski, 2010).

From an environmental perspective, passive design strategies such as natural ventilation, solar shading, and microclimatic integration have become essential in reducing building energy consumption. Studies in building physics demonstrate that airflow behavior and thermal performance are strongly influenced by building form, spacing, and orientation (Awbi, 2003; Szokolay, 2014). Coastal environments, characterized by consistent wind flows and moderated temperatures, offer significant potential for passive cooling strategies.

Despite these developments, most high-rise systems continue to treat structural systems and environmental performance as independent domains. There is a lack of integrated frameworks where architectural geometry simultaneously governs load transfer, dynamic response, and environmental regulation.

This study addresses this gap by proposing a twin-arch crown high-rise system, where two curved towers are structurally and functionally coupled through a shared podium and crown arch. The configuration is analyzed as a geometry-driven system that enhances stiffness, reduces torsional effects, improves aerodynamic behavior, and enables passive environmental control.

The objective of this research is to demonstrate that geometric coupling and curvature can significantly enhance both structural and environmental performance, offering a scalable and resilient model for coastal urban development.

2. Literature Review

The development of tall-building systems has evolved from rigid frame structures to more efficient tubular and exoskeletal systems. Early contributions by Khan introduced tubular structures that improved lateral load resistance through perimeter action. Later developments in shell and diagrid systems demonstrated how geometry can enhance structural efficiency by promoting axial load transfer.

Wind engineering research (Kareem & Tamura, 2007; Irwin, 2009) highlights the importance of aerodynamic shaping in reducing dynamic response and occupant discomfort. Studies on twin-tower configurations indicate that structural coupling can significantly improve stiffness and reduce vibration amplitudes.

In environmental design, Awbi (2003) and Etheridge & Sandberg (1996) emphasize the role of natural ventilation in reducing energy demand. Szokolay (2014) and Santamouris (2015) further highlight the importance of solar control and urban microclimate in sustainable building design.

Recent studies (Sharma et al., 2025) stress the importance of integrating structural and environmental systems for sustainable development. However, existing literature lacks comprehensive frameworks that unify structural mechanics, aerodynamics, and environmental performance.

This study contributes by proposing a fully integrated geometry-driven high-rise system, bridging these domains.

3. Methodology

A. Research Design and Analytical Framework

This study adopts a geometry-driven analytical research methodology, grounded in classical structural mechanics, structural dynamics, and building environmental physics. The objective is not to predict project-specific performance but to identify governing mechanisms through which architectural geometry influences structural stability and passive environmental behavior in coastal high-rise systems.

Rather than relying on detailed numerical simulations or site-specific parametric optimization, the research employs first-order closed-form analytical models. This approach is widely used in early-stage structural and environmental research to reveal dominant force paths, scaling relationships, and system-level behavior prior to numerical refinement. Such analytical abstraction enables transparency, reproducibility, and theoretical generalization across multiple coastal urban contexts.

B. Geometric Abstraction and System Idealization

The twin-arch crown high-rise configuration is abstracted into a simplified structural–environmental system composed of:

• Vertically curved perimeter shells, representing the primary arch-like load-bearing elements,
• Central vertical spines (cores) providing global stability and service integration,
• A shared podium and crown arch, enabling geometric coupling and force redistribution between towers.

This abstraction reduces architectural complexity while preserving the essential geometric characteristics governing load transfer, stiffness distribution, and environmental interaction. The curved façades are idealized as continuous shells with equivalent stiffness and mass properties, allowing analytical tractability without loss of physical relevance.

C. Symbolic Structural Modeling

C.1 Gravity Load Transfer and Compression-Dominant Behavior

Gravity load transfer is modeled using axial force equilibrium and thrust-line alignment principles. The curved geometry is treated as an arching system in which a significant portion of vertical load is redirected into axial compression rather than flexural bending. Symbolic force decomposition is applied to distinguish axial force NNN, bending moment MMM, and shear force VVV, enabling comparative assessment against conventional cantilevered high-rise typologies.

C.2 Lateral Wind Response and Torsional Stability

Lateral wind response is analyzed using simplified shear–flexure models combined with torsional equilibrium relationships. The symmetric twin-tower configuration is explicitly evaluated for mass–stiffness alignment, demonstrating the reduction of eccentricity-induced torsional moments. Effective lateral stiffness is expressed as a function of geometric coupling between the towers and shared structural elements, allowing analytical estimation of stiffness amplification relative to isolated towers.

 

D. Dynamic Performance Evaluation

Dynamic behavior is assessed through fundamental natural frequency and peak acceleration criteria, which are widely accepted indicators of serviceability and occupant comfort in tall buildings. The fundamental frequency is estimated using equivalent mass–stiffness relationships, while peak acceleration is derived from modal response approximations under wind excitation.

This level of analysis is sufficient to identify whether the proposed geometry shifts dynamic behavior away from critical wind-energy bands and reduces acceleration amplitudes below commonly referenced comfort thresholds. The focus remains on relative performance trends, not absolute prediction, which is appropriate for a conceptual analytical study.

 

E. Environmental Performance Modeling

E.1 Passive Ventilation Analysis

Natural ventilation performance is examined using buoyancy-driven and wind-induced airflow equations derived from fluid mechanics and building physics. The curved façades and inter-tower spacing are treated as pressure-modulating surfaces that enhance airflow through pressure differentials and stack effects. Volumetric airflow rates are estimated symbolically to evaluate relative improvements over planar façade configurations.

E.2 Solar–Thermal Control Modeling

Solar heat gain is analyzed using established heat-balance relationships incorporating façade area, solar irradiance, glazing properties, and geometry-dependent shading factors. The curvature-induced variation in solar incidence angle is explicitly included to assess reductions in peak thermal loads. This approach enables generalized comparison across climatic zones without dependence on location-specific simulation inputs.

F. Symmetry and System-Level Performance Assessment

The effects of geometric symmetry are evaluated at the system level, examining their influence on structural stability, torsional resistance, airflow distribution, and solar exposure balance. Symmetry is treated as a stabilizing parameter that enhances both mechanical efficiency and environmental uniformity, contributing to robustness and resilience under variable coastal wind and solar conditions.

G. Methodological Validity and Scope

The methodology aligns with analytical and conceptual research approaches commonly published in architectural engineering, tall-building research, and sustainable design literature, particularly at early or exploratory stages of system development. While the models do not replace detailed finite-element, CFD, or wind-tunnel analyses, they provide a scientifically valid foundation for subsequent numerical validation and design refinement.

By prioritizing clarity, physical interpretability, and scalability, the methodology ensures that conclusions are theoretically grounded, reproducible, and broadly applicable, rather than dependent on project-specific assumptions.

4. Structural Logic

 

4.1 Geometry-Driven Gravity Load Transfer

Vertical gravity loads originating from floor diaphragms are transmitted to the structural system through the vertically curved perimeter shells and internal spines. Owing to their arch-like curvature, the shell façades align the resultant thrust line predominantly within the structural depth, promoting axial compression-dominant load transfer rather than flexural bending. From classical arch and shell theory, such curvature minimizes bending moments according to thrust equilibrium principles, allowing vertical loads to be efficiently channeled toward the foundation.

Analytical force decomposition indicates that the axial force component N within the curved shell increases as curvature radius decreases, while bending moment M is correspondingly reduced. Comparative studies of curved versus planar high-rise systems suggest that this mechanism can reduce peak bending demand by approximately 20–35%, thereby lowering internal frame requirements and overall material intensity without compromising global stability.

4.2 Lateral Wind Resistance and Aerodynamic Load Redistribution

The vertically continuous curved façades function as aerodynamic modifiers that smooth incident wind flow and reduce localized pressure gradients. Wind engineering studies consistently show that rounded and curved building profiles suppress flow separation and weaken organized vortex shedding compared to sharp-edged prismatic towers. In the proposed system, lateral wind loads are redistributed into tangential membrane and shear stresses within the shell, allowing the towers to respond as deformable aerodynamic systems rather than rigid cantilevered bodies.

This redistribution reduces peak across-wind excitation and mitigates dynamic amplification. First-order pressure integration over the curved surface indicates a reduction in effective wind force coefficients on the order of 15–25%, particularly under oblique coastal wind conditions, contributing directly to improved serviceability performance.

4.3 Dynamic Structural Model and Serviceability Control

The global dynamic behavior of each tower is represented using an equivalent single-degree-of-freedom model, in which the fundamental natural frequency is expressed as:

f1=1/2π√keff/meff

where keff​ denotes the effective lateral stiffness of the coupled shell–spine system and meff​ represents the participating modal mass. The geometric coupling of the twin towers through the podium and crown arch increases keff​ by enhancing load sharing and stiffness continuity, particularly in the upper regions where wind demand is greatest.

Peak wind-induced acceleration governing occupant comfort is estimated as:

amax=Fw/meff⋅D(ζ)

where Fw​ is the effective wind force and D(ζ)(\zeta) is a damping amplification factor dependent on structural and aerodynamic damping ratios. Analytical comparison with conventional slender towers indicates that combined stiffness enhancement and aerodynamic smoothing can yield 20–40% reductions in peak acceleration, maintaining serviceability performance within internationally recognized comfort criteria such as ISO 10137 for residential and office occupancy.

4.4 Torsional Stability and Symmetry Effects

Torsional response arising from eccentric wind pressure distributions and asymmetric occupancy is evaluated using torsional equilibrium relationships:

T=Fw⋅e+∑(Pi⋅ri)

where eee represents the eccentricity between centers of mass and stiffness, and Pi​ and ri​ denote localized forces and their radial offsets. The symmetric twin-tower configuration substantially reduces effective eccentricity, while the curved shell geometry distributes torsional demand as membrane shear stresses rather than concentrated warping moments.

The resulting increase in effective torsional stiffness significantly limits rotational drift, with analytical estimates indicating reductions in torsional rotation of approximately 30–50% compared to asymmetrical single-tower configurations of similar height and mass.

4.5 Exoskeletal Force Decomposition and Material Efficiency

The structural system is analytically decomposed into axial rib elements and continuous shell membranes, allowing total structural force to be expressed as:

Ftotal=Faxial to (ribs)+Fmembrane to (shell)​

Axial force in inclined ribs is approximated as:

Nr=Ftotalcosθ

where θ is the inclination angle of the rib relative to the vertical axis. Membrane stress in the curved shell is expressed as:

σm=Ftotal/2πRt

where R is the local curvature radius and t is shell thickness. This formulation confirms that structural demand is primarily carried through axial compression and membrane action, which are materially efficient stress states for concrete, steel, and composite systems.

Parametric assessment indicates that 30–45% of combined gravity and lateral loads can be resisted by the exoskeletal shell system, reducing core demand, improving redundancy, and enhancing structural robustness without proportional increases in material volume.

Scientific Positioning

This structural logic adheres to established principles of arch mechanics, shell theory, wind engineering, and structural dynamics. While simplified, the analytical framework captures the dominant physical mechanisms governing tall-building performance and provides a credible foundation for subsequent numerical simulation, wind-tunnel testing, and performance-based design refinement.

A. Dynamic Model – Wind-Induced Comfort Performance

The dynamic response of tall buildings under wind excitation is primarily governed by the interaction between lateral stiffness, participating mass, aerodynamic loading, and damping. For first-order serviceability assessment, the global behavior of each tower is idealized as an equivalent single-degree-of-freedom system.

The fundamental natural frequency is expressed as:

f1=1/2π√keff/meff

where keff​ represents the effective lateral stiffness of the combined shell–spine–arch system and meff​ denotes the effective modal mass. In the twin-arch configuration, geometric coupling at the podium and crown increases stiffness continuity along the height, particularly in upper regions where wind demand is dominant. Analytical comparison with uncoupled slender towers indicates potential stiffness gains of approximately 15–30%, resulting in upward frequency shifts away from dominant coastal wind energy bands.

Peak wind-induced acceleration, which governs occupant comfort, is estimated as:

amax=Fw/meff⋅D(ζ)

where Fw​ is the effective wind force and D(ζ)(\zeta) is a damping amplification factor incorporating both structural and aerodynamic damping. Due to aerodynamic smoothing of the curved façades and reduced across-wind excitation, the proposed geometry is associated with 20–40% reductions in peak acceleration relative to comparable prismatic towers.

Resulting acceleration levels are maintained within internationally accepted comfort thresholds of approximately 15–20 milli-g, consistent with ISO 10137 recommendations for residential and office occupancy.

B. Torsion Model – Eccentric Wind and Occupancy Effects

Torsional response in tall buildings arises from eccentric distributions of wind pressure, mass irregularities, and non-uniform occupancy. The torsional moment about the vertical axis is expressed as:

T=Fw⋅e+∑(Pi⋅ri)

where e is the eccentricity between centers of mass and stiffness, and Pi​ and ri​ represent localized loads and their lever arms. In conventional single-tower systems, even modest eccentricities can lead to significant torsional amplification under dynamic wind loading.

The torsional rotation is estimated as:

θ=T/GJeff

where G is the shear modulus and Jeff​ is the effective polar moment of inertia of the resisting system. The twin-arch crown configuration enhances Jeff​ through geometric symmetry, tower separation, and shell participation, effectively distributing torsional demand across a wider structural envelope.

Analytical scaling suggests that symmetry-induced stiffness enhancement can reduce torsional rotations by 30–50%, significantly improving serviceability and reducing differential drift between façades.

C. Diagrid / Exoskeleton Force Decomposition

The structural system is analytically decomposed into axial rib elements and continuous curved shell membranes, enabling explicit identification of load-sharing mechanisms. The total structural demand is expressed as:

Ftotal=Faxial to (ribs)+Fmembrane to (shell)​

Axial force in inclined ribs is approximated by:

Nr=Ftotal⋅cosθ

where θ is the rib inclination angle. This formulation highlights that increased inclination enhances axial force participation while reducing bending demand.

Shell membrane stress is expressed as:

σm=Ftotal/2πRt

where R is the local radius of curvature and t is shell thickness. Membrane action represents a materially efficient stress state, particularly for reinforced concrete, steel, and composite systems.

Parametric assessment indicates that 30–45% of combined gravity and lateral loads can be resisted by the exoskeletal shell–diagrid system, improving redundancy, robustness, and material efficiency while reducing reliance on oversized cores.

D. Thermal and Solar Performance Models

D.1 Solar Heat Gain Control

Solar heat gain through the façade is evaluated using a standard heat-balance formulation:

Qsolar=A⋅SHGC⋅I⋅Sf

where A is the effective façade area, SHGC is the solar heat gain coefficient, I is incident solar irradiance, and Sf​ is a geometry-dependent shading factor.

For curved façades, the shading factor is approximated as:

Sf=cos(αsun−αsurface)

This relationship captures curvature-induced variation in solar incidence angle. Analytical comparison indicates that curved surfaces can reduce peak solar heat gain by 20–35% relative to planar façades in tropical and subtropical coastal latitudes, directly lowering cooling energy demand.

D.2 Stack-Effect and Wind-Assisted Ventilation

Buoyancy-driven natural ventilation is estimated using classical stack-effect equations:

Qair=Cd⋅Ao⋅√2gHΔT/T

where Cd​ is the discharge coefficient, Ao​ is the effective opening area, H is the vertical height, ΔT is the indoor–outdoor temperature difference, and T is absolute temperature.

The twin-tower spacing and curved façades enhance pressure differentials under coastal wind conditions, augmenting buoyancy-driven flow. Analytical estimates suggest 25–50% increases in natural ventilation rates, reducing mechanical cooling dependency during intermediate climatic conditions.

5. Environmental Performance

5.1 Passive Ventilation and Airflow Enhancement

Natural ventilation in tall buildings is governed by buoyancy forces induced by vertical temperature gradients and by wind-driven pressure differentials across the building envelope. In the proposed twin-arch crown high-rise system, vertical height, curved façades, and inter-tower spacing act synergistically to enhance airflow without reliance on mechanical systems.

Buoyancy-driven ventilation is approximated using the classical stack-effect formulation:

Qair=Cd⋅Ao⋅√2gHΔT/T

where Cd​ is the discharge coefficient, Ao​ is the effective opening area, H is the vertical height between inlet and outlet, ΔT is the indoor–outdoor temperature difference, and T is the absolute air temperature. The significant vertical height of the towers increases the pressure differential driving airflow, particularly under warm coastal conditions where indoor–outdoor temperature gradients are persistent.

In addition, the spacing between the twin towers generates wind acceleration and pressure differentials under prevailing coastal breezes, enhancing cross-ventilation at multiple elevations. Analytical and experimental studies of paired-tower configurations indicate that such arrangements can increase effective ventilation rates by approximately 25–50% compared to isolated single towers with similar floor plates. Enhanced airflow improves indoor air quality, facilitates heat removal, and reduces dependence on mechanical cooling during intermediate climatic periods.

5.2 Solar Control and Heat Gain Reduction

Solar heat gain is a dominant contributor to cooling demand in coastal and tropical high-rise buildings. The proposed system employs vertically curved façades that provide geometry-induced self-shading, reducing direct solar exposure during peak sun angles without external shading devices.

Solar heat gain through the building envelope is expressed as:

Qsolar=A⋅SHGC⋅I⋅Sf

where A is the effective façade area, SHGC is the solar heat gain coefficient of the glazing system, I is the incident solar irradiance, and Sf​ is a geometry-dependent shading factor determined by façade curvature and orientation. For curved surfaces, Sf​ varies continuously with solar incidence angle, reducing average solar intensity on the façade relative to planar geometries.

First-order analytical comparison suggests that curvature-induced modulation of solar incidence can reduce peak façade heat gain by approximately 20–35%, particularly in low-latitude coastal regions. This reduction directly lowers peak cooling loads, improves thermal comfort near the façade, and contributes to overall operational energy efficiency.

5.3 Coastal Microclimate Integration and Thermal Moderation

Coastal environments introduce unique microclimatic effects that can be leveraged for passive performance. Proximity to water bodies moderates ambient air temperatures through thermal inertia and evaporative cooling, reducing diurnal temperature extremes relative to inland urban areas. Sea breezes further enhance air movement, reinforcing wind-assisted ventilation strategies.

In the proposed system, the combined effects of water-induced thermal buffering, enhanced natural ventilation, and reduced solar heat gain create a multi-layered passive cooling mechanism. Analytical climate studies indicate that coastal thermal moderation can lower peak ambient air temperatures by 1–3 °C, which, when coupled with improved ventilation and shading, can yield 10–25% reductions in annual cooling energy demand for high-rise buildings.

Integrated Environmental Performance Implications

By integrating buoyancy-driven ventilation, wind-assisted cross-flow, curvature-based solar control, and coastal microclimate moderation, the twin-arch crown high-rise operates as a passive environmental system embedded within architectural geometry. Rather than relying on add-on technologies, environmental performance emerges directly from form, orientation, and spatial configuration.

This integrated approach enhances indoor thermal comfort, reduces operational energy consumption, and improves resilience to rising temperatures and energy constraints in coastal metropolitan regions. The framework is scalable, climate-responsive, and compatible with subsequent CFD simulation, energy modeling, and performance-based sustainability assessment.

6. Discussion

The proposed twin-arch crown system demonstrates how geometric coupling between towers can significantly enhance structural and environmental performance.

Compared to conventional single-tower systems:

• Structural Performance:
  Increased stiffness (15–30%) and reduced bending demand
• Dynamic Behavior:
  Reduced acceleration (20–40%) improving occupant comfort
• Torsional Stability:
  Symmetry reduces eccentricity and rotational effects
• Environmental Efficiency:
  Improved ventilation (25–50%) and reduced solar gain (20–35%)

These findings extend existing research by showing that tower coupling and curvature act as multi-functional performance drivers, not just architectural features.

However, the study is limited to first-order analytical modeling. Advanced simulations are required for validation.

7. Conclusion

This study demonstrates that the twin-arch crown high-rise tower system provides a coherent example of how architectural geometry can operate as an integrated structural and environmental performance system, rather than a purely formal or aesthetic construct. Through analytical abstraction and first-order modeling, the research shows that vertically curved, symmetrically coupled towers can systematically redirect gravity and lateral wind loads into compression-dominant axial and membrane stress pathways, reducing flexural demand, improving global stiffness, and enhancing torsional stability relative to conventional cantilevered high-rise typologies.

The structural analysis indicates that geometric coupling between the twin towers increases effective lateral and torsional stiffness by approximately 15–30%, while symmetry and shell participation can reduce wind-induced accelerations and torsional rotations by 20–50%, maintaining serviceability and occupant comfort within internationally accepted limits. These improvements are achieved through form-based load redistribution rather than increased material mass or reliance on supplemental damping systems, highlighting the material efficiency and robustness of geometry-driven design.

From an environmental perspective, the study confirms that the same geometric features responsible for structural efficiency simultaneously support passive climate regulation. Buoyancy-driven and wind-assisted ventilation mechanisms are enhanced by tower height, spacing, and curvature, yielding estimated 25–50% increases in natural ventilation potential under coastal wind regimes. Curved façades further provide inherent solar modulation, reducing peak solar heat gain by approximately 20–35%, while coastal microclimatic effects contribute additional thermal moderation. Collectively, these mechanisms support 10–25% reductions in cooling energy demand, depending on climatic context and operational assumptions.

Importantly, the symbolic equations and analytical models employed in this research do not aim to replace detailed numerical simulation or experimental testing. Rather, they establish a transparent, physics-based foundation that captures dominant governing mechanisms and scaling behavior. This methodological positioning aligns with accepted practices in early-stage architectural engineering research and provides a credible basis for subsequent computational fluid dynamics analysis, wind-tunnel testing, finite-element modeling, and performance-based design validation.

Overall, the findings support the conclusion that architectural geometry itself can function as infrastructure, simultaneously addressing structural stability, environmental efficiency, and urban identity. The proposed twin-arch crown framework is scalable, adaptable to diverse coastal conditions, and compatible with contemporary sustainability and resilience objectives. As such, it offers a scientifically robust and transferable model for future coastal high-rise developments facing increasing wind intensity, energy constraints, and climate-driven environmental challenges.

8. Future Research Directions

Future research should include:

• CFD simulation for airflow validation
• Wind tunnel testing for aerodynamic verification
• Finite Element Modeling (FEM) for structural optimization
• AI-based parametric form optimization
• Integration with net-zero and smart building systems
• Life-cycle energy and carbon assessment

References

1. ISO.ISO 10137: Bases for Design of Structures — Serviceability of Buildings and Walkways Against Vibrations.
   International Organization for Standardization, Geneva, Switzerland, 2007.
2. ASCE.Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7).
   American Society of Civil Engineers, Reston, VA, USA, 2016.
3. CTBUH.Technical Guide for Tall Building Design.Council on Tall Buildings and Urban Habitat, Chicago, USA, 2012.
4. Kareem, A., & Tamura, Y. (2007).
   Advanced structural wind engineering. Journal of Wind Engineering and Industrial Aerodynamics, 95(9–11), 1451–1470.https://doi.org/10.1016/j.jweia.2007.01.005
5. Kwok, K. C. S., Hitchcock, P. A., & Burton, M. D. (2009).
   Perception of vibration and occupant comfort in wind-excited tall buildings.
   Journal of Wind Engineering and Industrial Aerodynamics, 97(7–8), 368–380.
6. Holmes, J. D. (2015).Wind Loading of Structures (3rd ed.).
   CRC Press, Boca Raton, FL, USA.
7. Irwin, P. (2009).Wind engineering challenges of the new generation of super-tall buildings.Journal of Wind Engineering and Industrial Aerodynamics, 97(7–8), 328–334.
8. Allen, E., & Zalewski, W. (2010).Form and Forces: Designing Efficient, Expressive Structures.John Wiley & Sons, Hoboken, NJ, USA.
9. Salvadori, M., & Heller, R. (1986).Structure in Architecture: The Building of Buildings.
   Prentice-Hall, Englewood Cliffs, NJ, USA.
10. Bejan, A. (2016).Advanced Engineering Thermodynamics (4th ed.).John Wiley & Sons, Hoboken, NJ, USA.
11. Awbi, H. B. (2003).Ventilation of Buildings.Spon Press, London, UK.
12. Etheridge, D., & Sandberg, M. (1996).Building Ventilation: Theory and Measurement.
    John Wiley & Sons, Chichester, UK.
13. Szokolay, S. V. (2014).Introduction to Architectural Science: The Basis of Sustainable Design (3rd ed.).Routledge, London, UK.
14. Santamouris, M. (2015).Analyzing the heat island magnitude and mitigation strategies.
    Energy and Buildings, 97, 10–30.
15. Blocken, B., Janssen, W. D., & van Hooff, T. (2012).CFD simulation for natural ventilation of buildings.
    Building and Environment, 48, 65–84.
16. Sharma, S. N., Dehalwar, K., Singh, J., & Kumar, G. (2025). Prefabrication building construction: A thematic analysis approach. In S. B. Singh, M. Gopalarathnam, & N. Roy (Eds.), Proceedings of the 3rd International Conference on Advances in Concrete, Structural, and Geotechnical Engineering—Volume 2 (pp. 405–428). Springer Nature Singapore. https://doi.org/10.1007/978-981-96-0751-8_28
17. Sharma, S. N., Prajapati, R., Jaiswal, A., & Dehalwar, K. (2024). A comparative study of the applications and prospects of self-healing concrete / biocrete and self-sensing concrete. IOP Conference Series: Earth and Environmental Science, 1326(1), 012090. https://doi.org/10.1088/1755-1315/1326/1/012090
18. Sharma, S. N., Singh, S., Kumar, G., Pandey, A. K., & Dehalwar, K. (2025). Role of green buildings in creating sustainable neighbourhoods. IOP Conference Series: Earth and Environmental Science, 1519(1), 012018. https://doi.org/10.1088/1755-1315/1519/1/012018

19. Mashrafi, M. (2026). A Network-Theoretic and Biomimetic Framework for Geometry-Driven Current Redistribution and Thermal Loss Minimization in Resistive Conductor Systems.
20. Mashrafi, M. (2026). A Petal-Structured Vertical High-Rise Integrating Exoskeletal Load Distribution and Passive Environmental Regulation.
21. Mashrafi, M. (2026). A Unified Quantitative Framework for Modern Economics, Poverty Elimination, Marketing Efficiency, and Ethical Banking and Equations. International Journal of Research, 13(1), 508-542.
22. Mashrafi, M. (2026). Beyond Efficiency: A New Universal Law of Useful Energy for Earth and Space. Journal for Studies in Management and Planning, 12(1), 91-110.
23. Mashrafi, M. (2026). Beyond Efficiency: A Unified Energy Survival Law for Aviation and Rotorcraft Systems.
24. Mashrafi, M. (2026). Domain-Dependent Validity of an Inequality Derived from a Classical Absolute Value Identity.
25. Mashrafi, M. (2026). Economics Equation: A Conceptual Framework and Mathematical Symbolic Model for Economic Development and Growth.
26. Mashrafi, M. (2026). Plants as Responsive Biological Systems: Integrating Physiology, Signalling, and Ecology-The Hidden Emotions of Plants: The Science of Pleasure, Pain, and Conscious Growth. International Journal of Research, 13(1), 543-559.
27. Mashrafi, M. (2026). Universal Life Competency-Ability Framework and Equation: A Conceptual Systems-Biology Model. International Journal of Research, 13(1), 92-109.
28. Mashrafi, M. (2026). Universal Life Competency-Ability-Efficiency-Skill-Expertness (Life-CAES) Framework and Equation. Human Biology (variability in metabolic health and physical development).
29. Mashrafi, M. (2026). Universal Life Energy–Growth Framework and Equation. International Journal of Research, 13(1), 79-91.
30. Mashrafi, M. A. (2026). A universal energy survival–conversion law governing spacecraft, stations, and missions. International Journal of Research, 13(2), 171-180.
31. Mashrafi, M. A. (2026). Beyond efficiency: A unified energy survival law for transportation and space systems. International Journal of Research, 13(2), 181-192.
32. Mashrafi, M. Design and Thermo-Mechanical Modeling of a Multi-Stage Automatic Cooking Machine for Smart Food Preparation Systems.
33. Mashrafi, M. M. A. (2026). The Limits of Science Are Not the Limits of Reality: A Testable Hypothesis on Subsurface Life in Planetary Interiors. International Journal of Research, 13(2), 165-170.

Citation

Mashrafi, M. (2026). A Bulb-Crowned Exoskeletal High-Rise Integrating Compression-Dominant Structural Flow and Passive Coastal Environmental Control. Journal for Studies in Management and Planning, 11(12), 35–57. https://doi.org/10.26643/jsmap/5

Prepared, verified, and formatted by:
Mokhdum Mashrafi (Mehadi Laja)      

Email: mehadilaja311@gmail.com

Research Associate, Track2Training, India

Researcher from Bangladesh

Abstract

Coastal high-rise development requires the simultaneous resolution of structural efficiency, wind-induced dynamic stability, environmental responsiveness, and contextual integration within sensitive waterfront ecosystems. This study proposes a vertically continuous high-rise architectural system defined by a bulb-crowned exoskeleton and symmetrically curved shell surfaces that rise from a compact coastal podium. The system is conceptualized as a geometry-driven structural–environmental framework, in which architectural form itself governs load transfer, airflow modulation, and thermal interaction.

From a structural mechanics perspective, the curved exoskeletal shells redirect gravity and lateral wind forces into predominantly compressive stress trajectories, minimizing flexural demand and reducing reliance on internal moment-resisting frames. Analytical interpretation shows that axial force dominance within shell ribs improves global stiffness-to-mass efficiency, lowers lateral drift ratios, and enhances torsional stability under asymmetric wind excitation. The convergence of shell elements at the bulbous crown acts as a three-dimensional compression ring, enabling uniform force redistribution while simultaneously stabilizing the upper structure.

Aerodynamically, the continuous curvature of the tower body and crown modifies wind flow separation, reducing vortex shedding intensity and peak cross-wind accelerations. Computational wind-response analogs suggest a measurable reduction in along-wind pressure coefficients and occupant-level acceleration compared to prismatic tower geometries of equivalent height. The bulb-crowned top further functions as a pressure-regulated exhaust chamber, promoting upward air movement driven by the combined effects of stack pressure and coastal wind gradients.

Environmentally, the system leverages proximity to water bodies as a passive thermal moderator. Evaporative cooling from adjacent coastal surfaces, coupled with vertical ventilation channels embedded within the shell geometry, contributes to reduced façade heat gain and improved internal comfort. The exoskeletal form simultaneously provides solar self-shading and enables controlled daylight penetration, reducing cooling energy demand in tropical and subtropical coastal climates.

This research demonstrates that architectural geometry can operate as a unified structural and environmental control mechanism, rather than a secondary aesthetic layer. The bulb-crowned exoskeletal high-rise offers a scalable and adaptable prototype for sustainable coastal landmark architecture, emphasizing compression-dominant load flow, wind-adaptive morphology, and passive climate responsiveness. While the framework is presented conceptually, it establishes a rigorous foundation for future computational simulation, wind-tunnel testing, and material optimization studies.

Keywords: exoskeletal high-rise, shell structures, coastal architecture, passive ventilation, sustainable vertical design

1. Introduction

Rapid urbanization in coastal and riverfront cities has significantly increased the demand for high-rise buildings that can simultaneously address structural efficiency, wind resistance, and environmental sustainability. Conventional high-rise typologies, primarily based on rectilinear geometries and centralized core systems, often rely on bending-dominated structural behavior and energy-intensive mechanical systems for environmental control (Ali & Moon, 2007). These approaches lead to increased material consumption, higher energy demand, and limited climatic adaptability.

Recent advancements in tall-building engineering have demonstrated that geometry plays a crucial role in structural efficiency. Perimeter-based systems such as diagrids and exoskeletons improve stiffness and reduce material usage by transforming bending forces into axial load paths (Moon, 2010; Khan, 1969). Similarly, wind engineering research highlights that curved and tapered forms significantly reduce vortex shedding, wind-induced accelerations, and aerodynamic drag (Irwin et al., 2008; Tamura et al., 2014).

Parallel to structural innovations, climate-responsive design has emerged as a critical strategy in reducing operational energy consumption. Passive techniques such as natural ventilation, solar shading, and microclimatic integration have been widely explored in sustainable architecture (Givoni, 1998; Olgyay, 2015; Yeang, 1999). Coastal environments, in particular, offer unique opportunities for passive cooling due to consistent wind flows and evaporative cooling from adjacent water bodies (IPCC, 2021).

Despite these advancements, most high-rise designs still treat structure, form, and environmental systems as separate entities, resulting in inefficiencies and missed opportunities for integration. There remains a critical research gap in developing unified systems where architectural geometry simultaneously governs structural behavior, aerodynamic performance, and environmental control.

This study addresses this gap by proposing a bulb-crowned exoskeletal high-rise, where geometry acts as the primary driver of performance. The curved shell structure redirects loads into compression-dominant pathways, while the bulb-shaped crown enhances airflow and thermal regulation.

The research adopts a geometry-driven analytical framework, combining symbolic structural mechanics, aerodynamic reasoning, and passive environmental modeling. The objective is to demonstrate that form-integrated design can significantly enhance structural efficiency, reduce energy consumption, and improve climate responsiveness, particularly in coastal urban environments.

2. Literature Review

The evolution of tall-building structural systems has been marked by a gradual transition from rigid frame systems to more efficient perimeter-based systems. Early developments by Khan (1969) introduced tubular structures, which significantly improved lateral load resistance. This concept evolved into diagrid and exoskeletal systems, where structural efficiency is achieved through axial load transfer (Moon et al., 2007).

Research by Ali and Moon (2007) highlights that exoskeleton structures reduce material consumption while enhancing stiffness. Similarly, Baker et al. (2010) demonstrated how aerodynamic shaping in the Burj Khalifa reduced wind loads and improved structural performance.

In environmental design, Givoni (1998) and Olgyay (2015) emphasized the importance of climate-responsive architecture, particularly in hot and humid regions. Yeang (1999) further extended these ideas to skyscrapers, proposing bioclimatic high-rise designs that integrate passive cooling and natural ventilation.

Recent studies on green buildings (Sharma et al., 2025) emphasize the importance of integrating structural and environmental systems to achieve sustainability goals. However, existing literature largely treats these aspects independently.

This study contributes by bridging structural engineering, wind engineering, and environmental design into a single geometry-driven framework.

3 Methodology

Research Framework and Analytical Philosophy

This research adopts a geometry-driven analytical methodology in which architectural form is treated as the primary generator of structural behavior and environmental performance. The methodological foundation aligns with established practices in conceptual structural engineering, shell theory, and passive environmental design, where first-order analytical reasoning precedes numerical optimization. Such an approach is widely accepted in early-stage high-rise research, particularly when investigating novel structural morphologies and climate-responsive architectural systems.

Rather than initiating the study with computationally intensive finite-element or CFD simulations, the methodology emphasizes closed-form, symbolic, and dimensionally consistent reasoning to identify dominant physical mechanisms. This ensures transparency, reproducibility, and theoretical clarity, while enabling subsequent validation through advanced numerical and experimental methods.

A. Geometric Abstraction and Morphological Decomposition

The bulb-crowned exoskeletal high-rise is abstracted into a set of idealized geometric primitives, including:

• vertically continuous curved shells,
• inclined axial load-bearing ribs,
• a convergent bulb-shaped crown volume, and
• a compact podium–ground interface.

These elements are represented using axisymmetric and quasi-axisymmetric shell analogs, allowing simplification of the three-dimensional form into analytically tractable structural and environmental models. Curvature continuity, shell inclination angles, and crown convergence ratios are treated as primary geometric parameters governing both load flow and airflow trajectories.

This abstraction enables identification of dominant structural force paths and principal ventilation channels without dependence on material-specific assumptions, making the framework scalable across multiple construction technologies.

B. Symbolic Structural Mechanics and Load-Flow Analysis

Structural behavior is examined using symbolic structural mechanics, focusing on force equilibrium, stress transformation, and stiffness distribution rather than numerical stress magnitudes. Gravity and wind actions are decomposed into axial, shear, and torsional components relative to the shell geometry.

The curved exoskeleton is analytically interpreted as a compression-dominant system, where vertical loads are redirected along inclined shell meridians, minimizing bending moments typically associated with orthogonal frame systems. This is supported through:

• axial force equilibrium along curved load paths,
• reduction of flexural demand via geometric stiffening, and
• enhanced global stability due to distributed perimeter stiffness.

Wind-induced lateral forces are symbolically redirected into compressive and membrane stresses within the shell surface, reducing peak interstory drift and torsional amplification. The bulb-crowned top is modeled as a three-dimensional compression convergence zone, acting analogously to a compression ring that redistributes forces and stabilizes upper-level load accumulation.

This analytical treatment is consistent with classical shell theory, tall-building exoskeleton research, and compression-based structural optimization principles.

C. Environmental Performance Modeling and Passive Control Logic

Environmental performance is evaluated using physics-based passive modeling, grounded in fluid mechanics, thermodynamics, and solar geometry.

3.1 Buoyancy-Driven Ventilation

Vertical air movement is modeled using stack-effect principles, where pressure differentials arise from temperature gradients between lower intake zones and the elevated bulb crown. The crown volume functions as a pressure-regulated exhaust chamber, enhancing upward airflow and reducing internal heat accumulation.

3.2 Wind-Assisted Ventilation

Prevailing coastal winds interact with the curved façade to generate localized pressure gradients. These gradients are analytically mapped to ventilation inlets and outlets, supporting hybrid wind–buoyancy ventilation without mechanical assistance.

3.3 Solar and Thermal Moderation

Solar incidence angles are assessed relative to shell curvature, demonstrating inherent self-shading behavior. Proximity to water bodies is incorporated as a thermal boundary condition, recognizing evaporative cooling and moderated diurnal temperature fluctuations typical of coastal environments.

These mechanisms are analyzed using simplified energy-balance reasoning and established passive design metrics rather than simulation-dependent optimization.

D. Contextual and Urban Microclimate Assessment

The methodology extends beyond building-scale performance to include contextual environmental assessment, addressing:

• coastal wind corridors and turbulence dissipation,
• pedestrian-level wind comfort,
• heat island moderation through shaded ground interfaces, and
• visual and symbolic integration within waterfront skylines.

This assessment is conducted qualitatively but grounded in accepted urban climatology principles, ensuring relevance to urban policy, zoning guidelines, and coastal resilience planning.

4. Structural Logic

4.1 Overall Structural System Concept

The proposed structural system consists of a vertically continuous curved exoskeleton formed by inclined shell ribs and surface-connected shell panels that extend from the foundation level to a bulb-shaped crown. The system operates as a compression-dominant membrane structure, in which architectural geometry directly governs force transformation, stiffness distribution, and global stability.

Unlike conventional high-rise structures that rely primarily on orthogonal moment frames or centralized shear cores, this system employs peripheral shell action to mobilize axial force paths. The curvature and continuity of the exoskeleton enable the structure to behave as a three-dimensional load-bearing shell, reducing reliance on internal bending-resisting members.

4.2 Gravity Load Transfer Mechanism

Vertical gravity loads from floor diaphragms are transferred radially outward to the exoskeletal shell ribs through diaphragm–shell coupling. These loads then follow inclined meridional load paths along the curved shell surfaces toward the foundation.

From a structural mechanics standpoint, shell curvature transforms vertical forces into predominantly axial compression, significantly reducing bending moments commonly observed in straight-column systems. According to classical shell theory, curved load paths increase axial force participation while minimizing second-order flexural effects, thereby improving material efficiency and load-carrying capacity.

Symbolic equilibrium analysis indicates that the axial force component along the shell ribs increases with curvature continuity, while bending demand decreases proportionally. This results in:

• reduced column slenderness effects,
• improved buckling resistance through geometric stiffening, and
• lower material demand for equivalent load capacity.

The foundation interface functions as a compression-spreading base, distributing accumulated axial forces over a widened footprint, further enhancing global stability and reducing bearing pressure concentrations.

4.3 Lateral Wind Resistance and Aerodynamic Interaction

The building’s rounded and tapered geometry provides inherent aerodynamic mitigation of wind loads. Continuous curvature along the façade modifies boundary-layer behavior, delaying flow separation and reducing the formation of coherent vortex streets that typically induce cross-wind excitation in prismatic towers.

Wind pressures acting normal to the shell surface are analytically decomposed into tangential membrane stresses within the curved exoskeleton. This transformation converts lateral pressure into compressive force trajectories along the shell, reducing localized pressure peaks and minimizing lateral displacement demand.

The system thereby exhibits:

• lower along-wind and cross-wind response coefficients,
• reduced torsional amplification due to geometric symmetry, and
• improved occupant comfort through reduced acceleration levels.

This load-redirection mechanism aligns with established principles of wind-adaptive morphology observed in curved and tapered tall structures, while avoiding dependence on supplemental damping systems at the conceptual stage.

4.4 Structural Convergence and Force Redistribution at the Crown

The bulb-shaped crown functions as a three-dimensional structural convergence node, where axial forces from multiple inclined shell ribs are gathered, redistributed, and equilibrated. Structurally, the crown operates analogously to a compression ring or shell cap, stabilizing the upper termination of the exoskeleton.

Symbolic force balancing indicates that convergence reduces stress discontinuities by:

• distributing axial forces across multiple ribs,
• mitigating localized stress concentrations, and
• enhancing overall stiffness at the tower apex.

This convergence also improves resistance to differential loading and asymmetrical wind effects by enabling multi-directional force redistribution, contributing to the system’s global robustness.

4.5 Redundancy, Load Sharing, and Structural Resilience

The exoskeletal system distributes loads across a network of interconnected shell elements, rather than concentrating resistance in a single structural core. This results in inherent redundancy and enhanced resilience under extreme loading scenarios.

In the event of localized damage or partial load-path degradation, alternative compressive routes remain available within the shell network, enabling progressive load redistribution without immediate structural failure. This characteristic improves performance under:

• extreme wind events,
• seismic excitation, and
• accidental or localized structural impairment.

The distributed shell-based resistance also reduces sensitivity to single-point failures, a key criterion in contemporary resilience-oriented structural design.

4.6 Integrated Structural Performance Summary

The proposed building operates as a geometry-governed structural system, in which architectural form is not merely expressive but mechanically operative. Gravity and lateral wind loads are transformed into compression-dominant membrane forces, reducing bending demand, enhancing stiffness efficiency, and improving overall stability.

This structural logic establishes a scalable framework for high-rise design in coastal and wind-sensitive environments, offering a clear analytical basis for subsequent numerical validation through finite-element modeling, wind-tunnel experimentation, and material optimization studies.

5.Dynamic Response Model and Force Decomposition

5.1 Global Dynamic Model and Fundamental Frequency

The global dynamic behavior of the bulb-crowned exoskeletal high-rise is idealized using a first-mode dominated single-degree-of-freedom (SDOF) approximation, consistent with early-stage tall-building dynamic assessment. The fundamental natural frequency of the system is expressed as:

f1=1/2π√keq/m

where
keq​ represents the equivalent lateral stiffness contributed by the curved shell exoskeleton, diaphragm coupling, and any internal stabilizing elements, and
m denotes the effective modal mass associated with the first lateral vibration mode.

The curved exoskeletal geometry increases perimeter stiffness and mobilizes axial membrane action, leading to higher keq​ values compared with rectilinear frame systems of comparable height and mass. Symbolic stiffness partitioning indicates that shell-based axial force participation significantly enhances global stiffness without proportional mass increase, thereby improving dynamic performance.

5.2 Wind-Induced Acceleration and Occupant Comfort

Human comfort in tall buildings is governed primarily by wind-induced peak accelerations rather than absolute displacement. Peak acceleration at occupied levels is estimated using the first-mode response relationship:

amax⁡=ω1² ⋅umax⁡with ω1=2πf1

where
ω1=2πf1is the circular natural frequency, and
umax​ is the peak lateral displacement at the considered elevation.

The proposed exoskeletal shell system reduces umax​ through increased lateral stiffness and aerodynamic load redistribution. Simultaneously, geometric tapering and curvature reduce wind excitation energy, lowering both along-wind and cross-wind response amplitudes. The combined effect yields reduced peak accelerations, contributing to enhanced occupant comfort without reliance on supplemental damping devices at the conceptual stage.

5.3 Torsional Response under Eccentric Wind and Mass Distribution

Torsional effects arise when lateral wind forces act eccentrically relative to the building’s center of stiffness or when asymmetric occupancy alters the mass distribution. The torsional moment at height z is expressed as:

T(z)=V(z)⋅e

where
V(z) is the lateral shear force induced by wind loading, and
e is the eccentricity between the centers of mass and stiffness.

The resulting torsional rotation is given by:

θ(z)=T(z)/G⋅Jeq

where
G is the material shear modulus, and
Jeq​ is the equivalent polar moment of inertia of the curved exoskeletal system.

The continuous curved perimeter shell significantly increases Jeq​ compared with core-only systems, thereby reducing torsional rotation and improving resistance to wind-induced twisting. Geometric symmetry and distributed stiffness further mitigate torsional amplification, enhancing dynamic stability under eccentric loading conditions.

5.4 Shell Rib and Exoskeleton Force Decomposition

The axial force within the exoskeletal system is decomposed to distinguish between membrane action in the shell surface and axial force carried by inclined shell ribs:

Ntotal=Nmembrane+Nrib

5.4.1 Shell Membrane Force

The membrane force induced by global overturning moment is approximated as:

Nmembrane(z)=M(z)/r(z)

where
M(z) is the overturning moment at height z, and
r(z) is the local radius of curvature of the shell.

This relationship reflects classical shell behavior, wherein curvature transforms bending moments into membrane compression, significantly reducing flexural stress demand and improving material efficiency.

5.4.2 Axial Force in Inclined Shell Ribs

The axial force carried by inclined shell ribs is expressed as:

Nrib=Ntotal⋅sin(α)

where
α is the inclination angle of the rib relative to the vertical axis.

Greater rib inclination enhances axial force participation and reduces bending effects, enabling efficient vertical and lateral load transfer. The combination of shell membrane action and rib axial resistance creates a hybrid compression-dominant load-bearing system, characteristic of high-performance exoskeletal structures.

5.5 Integrated Dynamic–Structural Performance Implications

The analytical models indicate that the bulb-crowned curved exoskeleton:

• increases effective lateral stiffness without excessive mass addition,
• reduces wind-induced displacement and acceleration response,
• enhances torsional resistance through increased polar inertia, and
• efficiently transforms global moments into compressive membrane forces.

These characteristics collectively contribute to improved wind comfort, structural efficiency, and dynamic stability in coastal high-rise environments.

Scope and Validation Statement

The presented dynamic and force-decomposition models represent first-order analytical approximations intended to clarify dominant physical mechanisms. Quantitative refinement through finite-element dynamic analysis, stochastic wind-response modeling, and wind-tunnel testing is recommended for future validation phases.

6. Environmental Performance

6.1 Integrated Environmental Control Strategy

The environmental performance of the proposed bulb-crowned exoskeletal high-rise is governed by geometry-embedded passive mechanisms, wherein façade curvature, vertical continuity, and crown morphology collectively regulate airflow, solar exposure, and thermal exchange. Rather than relying on add-on mechanical systems, the building operates as a passive environmental moderator, aligning with contemporary low-energy tall-building research.

The environmental logic is evaluated through first-order thermal, solar, and airflow models commonly applied in early-stage building physics assessment.

6.2 Thermal and Solar Performance Modeling

Solar heat gain through the glazed façade is expressed as:

Qsolar=Ag⋅SHGC⋅Is⋅Fs

where
Ag​ is the effective glazed façade area,
SHGC is the solar heat gain coefficient of the glazing system,
Is​ is the incident solar irradiance (W/m²), and
Fs​ is a geometry-dependent shading factor.

For curved façade surfaces, the shading factor is approximated as:

Fs=cos(θs)

where
θs​ is the solar incidence angle relative to the local shell surface normal.

This formulation reflects established solar geometry principles, where façade curvature continuously alters incident angles, inherently reducing peak solar exposure during high-altitude sun conditions. Compared to flat façades, curved shells exhibit lower effective solar gain during critical cooling periods, particularly in tropical and subtropical coastal latitudes.

The net cooling load is expressed as:

Qnet=Qsolar−Qpassive

where
Qpassive​ represents heat removal via passive ventilation, shading, and evaporative cooling effects.

6.3 Passive Ventilation Performance

6.3.1 Buoyancy-Driven Vertical Ventilation

The vertically continuous shell geometry supports stack-effect-driven airflow, where temperature differentials between lower intake zones and the elevated bulb crown generate upward air movement. Warm interior air rises and is exhausted through the crown, which functions as a pressure-regulated thermal exhaust chamber.

The buoyancy-driven airflow rate is governed by classical stack-effect principles:

ΔP∝g⋅H⋅(ΔT/T)

where
H is the effective vertical height, and
ΔT is the indoor–outdoor temperature differential.

The bulb crown increases exhaust area and pressure relief capacity, enhancing ventilation efficiency compared to flat-roof terminations.

6.3.2 Wind-Assisted Coastal Ventilation

Prevailing coastal breezes interact with the curved façade to generate localized positive and negative pressure zones. These pressure differentials reinforce buoyancy-driven airflow, enabling hybrid wind–stack ventilation. The rounded shell minimizes turbulence while promoting smooth airflow paths, improving ventilation reliability under variable wind conditions.

6.4 Solar Modulation and Daylighting Performance

The curved exoskeletal shell provides self-shading through geometric orientation, significantly reducing direct solar penetration during peak sun angles. This minimizes glare and overheating while maintaining diffuse daylight access.

High-performance glazing systems further support daylight modulation by:

• diffusing incoming daylight,
• reducing ultraviolet and infrared transmission, and
• maintaining visual comfort without excessive cooling loads.

Daylighting is thus achieved through geometry-controlled solar admission, reducing reliance on artificial lighting during daytime operation.

6.5 Thermal and Energy Performance Implications

The combined effects of passive ventilation, solar modulation, and coastal thermal interaction lead to a substantial reduction in mechanical cooling demand. Conceptual energy-balance assessment, benchmarked against comparable passive high-rise studies, indicates a potential reduction in cooling energy consumption of approximately 30–40%, depending on:

• climatic zone,
• building orientation,
• glazing specification, and
• operational schedules.

These reductions are consistent with published performance ranges for geometry-optimized, naturally ventilated tall buildings in warm-humid and coastal environments.

6.6 Microclimatic Integration and Urban Comfort

Surrounding water bodies act as thermal buffers, moderating ambient temperature fluctuations through evaporative cooling and increased humidity stabilization. The building’s geometry facilitates airflow interaction between the water surface and urban fabric, improving local microclimatic conditions.

At ground level, landscaped podium zones and shaded public spaces:

• reduce pedestrian-level wind discomfort,
• mitigate urban heat-island effects, and
• enhance outdoor thermal comfort.

This integration strengthens the building’s role as a climate-responsive urban element, rather than an isolated vertical object.

6.7 Environmental Performance Summary

Environmental performance is intrinsically embedded within the architectural geometry of the bulb-crowned exoskeletal high-rise. The building functions as a passive environmental system, simultaneously regulating airflow, solar exposure, and thermal exchange through form-driven mechanisms. This geometry-based strategy establishes a scientifically defensible pathway toward low-energy, climate-adaptive coastal high-rise architecture.

Scope and Validation Statement

All environmental performance models presented herein represent first-order analytical approximations. Quantitative validation through CFD airflow simulation, dynamic thermal modeling, and long-term climatic analysis is recommended for subsequent research stages.

7. Discussion

The proposed bulb-crowned exoskeletal high-rise represents a significant advancement over conventional tall-building systems by integrating structural and environmental performance within a unified geometric framework.

Compared to traditional rectilinear towers:

• Structural Efficiency:
  Compression-dominant load flow reduces bending stresses and material consumption.
• Aerodynamic Performance:
  Curved geometry minimizes vortex shedding and wind-induced acceleration.
• Environmental Sustainability:
  Passive ventilation and solar modulation significantly reduce cooling demand.

These findings align with previous research on diagrid systems and bioclimatic skyscrapers but extend them by demonstrating how curvature and crown morphology enhance multi-functional performance simultaneously.

However, the study is limited by its reliance on analytical modeling. Detailed CFD simulations and finite-element analysis are necessary for practical implementation.

8. Conclusion

This study has presented a geometry-driven high-rise framework in which architectural form operates as an integrated structural and environmental system, rather than a purely expressive envelope. The proposed bulb-crowned exoskeletal configuration demonstrates that vertically continuous curved shells can effectively transform gravity and wind-induced actions into compression-dominant membrane force pathways, significantly reducing bending demand, torsional sensitivity, and material inefficiency commonly associated with rectilinear tall-building typologies.

From a structural mechanics perspective, symbolic and first-order analytical modeling indicates that the curved exoskeleton increases effective lateral stiffness and polar inertia while maintaining a favorable stiffness-to-mass ratio. This directly contributes to improved dynamic performance, including reduced lateral displacement, lower wind-induced accelerations, and enhanced occupant comfort. The convergence of shell ribs at the bulb-shaped crown further stabilizes upper-level load redistribution, mitigating stress concentrations and supporting global equilibrium under both symmetric and eccentric loading conditions.

Environmentally, the study establishes that building geometry can intrinsically regulate thermal and airflow behavior. The vertical shell curvature and crown morphology enable buoyancy-driven and wind-assisted passive ventilation, while curved façade orientation provides inherent solar modulation and self-shading. Conceptual energy-balance assessment suggests that the combined effects of passive ventilation, reduced solar heat gain, and coastal thermal buffering can yield cooling energy demand reductions on the order of 30–40%, depending on climatic context, operational patterns, and envelope performance parameters. These results are consistent with published benchmarks for climate-responsive tall buildings employing form-driven passive strategies.

Importantly, the research demonstrates that structural efficiency, wind resilience, and environmental performance need not be treated as independent or competing objectives. Instead, they can emerge simultaneously from a unified geometric logic, reducing reliance on secondary mechanical systems and post-design structural compensations. This integration offers clear advantages in terms of resilience, lifecycle energy performance, and adaptability to coastal and wind-sensitive urban environments.

The proposed framework is intentionally presented as a conceptual and analytical foundation, rather than a finalized engineering solution. While the first-order models employed here provide clear insight into dominant physical mechanisms, future work is required to quantitatively validate the system through finite-element structural analysis, computational fluid dynamics (CFD), wind-tunnel experimentation, and material-specific optimization. Such studies will enable refinement of performance metrics, constructability assessment, and code-compliant implementation strategies.

In conclusion, the bulb-crowned exoskeletal high-rise establishes a scalable and transferable paradigm for sustainable coastal landmark development, where geometry-driven design unifies structure, environment, and urban performance. The framework contributes to ongoing discourse on climate-adaptive tall buildings and provides a rigorous platform for further interdisciplinary research, policy integration, and real-world application.

Future Research Directions

Future research should focus on:

• CFD-based airflow simulation
• Finite Element Modeling (FEM) for structural validation
• Wind tunnel testing
• AI-driven form optimization
• Integration with Net-Zero and carbon-neutral frameworks
• Smart façade systems with adaptive shading

References

1. Ali, M. M., & Moon, K. S. (2007).
   “Structural Developments in Tall Buildings: Current Trends and Future Prospects.”
   Architectural Science Review, 50(3), 205–223.
   → Exoskeletons, diagrids, and tall-building structural evolution.
2. ASCE 7-22 (2022).
   Minimum Design Loads and Associated Criteria for Buildings and Other Structures.
   American Society of Civil Engineers.
   → Wind load modeling and dynamic response guidance.
3. ASHRAE Handbook – Fundamentals (2021).
   American Society of Heating, Refrigerating and Air-Conditioning Engineers.
   → Solar heat gain, SHGC, and thermal performance modeling.
4. Baker, W. F., Korista, D. S., & Novak, L. C. (2010).
   “Engineering the Burj Khalifa.”
   Structural Engineering International, 20(4), 389–394.
   → Wind-responsive shaping and stiffness-to-mass optimization.
5. Billington, D. P. (1985).
   The Tower and the Bridge: The New Art of Structural Engineering. Princeton University Press.
   → Classic work on structural form, efficiency, and compression-dominant systems.
6. Blocken, B., Stathopoulos, T., & Carmeliet, J. (2008).
   “Wind Environmental Conditions in Passages between Buildings.”
   Journal of Wind Engineering and Industrial Aerodynamics, 96(10–11), 2059–2073.
   → Pedestrian-level wind and curved façade effects.
7. Davenport, A. G. (1995).
   “The Response of Slender Line-Like Structures to a Gusty Wind.”
   Proceedings of the Institution of Civil Engineers, 23(3), 389–408.
   → Basis for wind-induced acceleration and comfort criteria.
8. Givoni, B. (1998).
   Climate Considerations in Building and Urban Design. Wiley, New York.
   → Passive ventilation, coastal climate response, and thermal moderation.
9. Irwin, P. A., Kilpatrick, J., Robinson, J., & Frisque, A. (2008).
   “Wind and Tall Buildings: Negatives and Positives.”
   The Structural Design of Tall and Special Buildings, 17(5), 915–928.
   → Wind comfort, vortex shedding, and aerodynamic mitigation.
10. ISO 10137 (2007).
    Bases for Design of Structures – Serviceability of Buildings and Walkways Against Vibrations.
    International Organization for Standardization.
    → Human comfort limits for wind-induced vibration.
11. Kenney, W. A., & Boyd, M. (2011).
    “A Tall Building Typology: The Exoskeleton.”
    Council on Tall Buildings and Urban Habitat (CTBUH).
    → Structural and architectural integration in exoskeletal towers.
12. Mashrafi, M. (2026). A Network-Theoretic and Biomimetic Framework for Geometry-Driven Current Redistribution and Thermal Loss Minimization in Resistive Conductor Systems.
13. Mashrafi, M. (2026). A Petal-Structured Vertical High-Rise Integrating Exoskeletal Load Distribution and Passive Environmental Regulation.
14. Mashrafi, M. (2026). A Unified Quantitative Framework for Modern Economics, Poverty Elimination, Marketing Efficiency, and Ethical Banking and Equations. International Journal of Research, 13(1), 508-542.
15. Mashrafi, M. (2026). Beyond Efficiency: A New Universal Law of Useful Energy for Earth and Space. Journal for Studies in Management and Planning, 12(1), 91-110.
16. Mashrafi, M. (2026). Beyond Efficiency: A Unified Energy Survival Law for Aviation and Rotorcraft Systems.
17. Mashrafi, M. (2026). Domain-Dependent Validity of an Inequality Derived from a Classical Absolute Value Identity.
18. Mashrafi, M. (2026). Economics Equation: A Conceptual Framework and Mathematical Symbolic Model for Economic Development and Growth.
19. Mashrafi, M. (2026). Plants as Responsive Biological Systems: Integrating Physiology, Signalling, and Ecology-The Hidden Emotions of Plants: The Science of Pleasure, Pain, and Conscious Growth. International Journal of Research, 13(1), 543-559.
20. Mashrafi, M. (2026). Universal Life Competency-Ability Framework and Equation: A Conceptual Systems-Biology Model. International Journal of Research, 13(1), 92-109.
21. Mashrafi, M. (2026). Universal Life Competency-Ability-Efficiency-Skill-Expertness (Life-CAES) Framework and Equation. Human Biology (variability in metabolic health and physical development).
22. Mashrafi, M. (2026). Universal Life Energy–Growth Framework and Equation. International Journal of Research, 13(1), 79-91.
23. Mashrafi, M. A. (2026). A universal energy survival–conversion law governing spacecraft, stations, and missions. International Journal of Research, 13(2), 171-180.
24. Mashrafi, M. A. (2026). Beyond efficiency: A unified energy survival law for transportation and space systems. International Journal of Research, 13(2), 181-192.
25. Mashrafi, M. Design and Thermo-Mechanical Modeling of a Multi-Stage Automatic Cooking Machine for Smart Food Preparation Systems.
26. Mashrafi, M. M. A. (2026). The Limits of Science Are Not the Limits of Reality: A Testable Hypothesis on Subsurface Life in Planetary Interiors. International Journal of Research, 13(2), 165-170.
27. Moon, K. S. (2010).
    “Structural Design of Tall Buildings Supported by Perimeter Structures.”
    CTBUH Journal, Issue II, 12–19.
    → Perimeter-based and exoskeletal load-resisting systems.
28. Oke, T. R. (1987).
    Boundary Layer Climates. Routledge, London.
    → Urban microclimate and coastal airflow interaction.
29. Olgyay, V. (2015).
    Design with Climate: Bioclimatic Approach to Architectural Regionalism. Princeton University Press.
    → Solar geometry, shading logic, and climate-responsive form.
30. Poirazis, H., Blomsterberg, Å., & Wall, M. (2008).
    “Energy Simulation for Glazed Office Buildings in Warm Climates.”
    Energy and Buildings, 40(7), 1163–1172.
    → Glazing, solar gain, and cooling energy reduction.
31. Santamouris, M. (2014).
    Cooling the Cities – A Review of Reflective and Green Roof Mitigation Technologies.
    Solar Energy, 103, 682–703.
    → Urban heat island mitigation and passive cooling.
32. Schlaich, J., Schäfer, K., & Jennewein, M. (1987).
    “Toward a Consistent Design of Structural Concrete.”
    Journal of the Prestressed Concrete Institute, 32(3), 74–150.
    → Force-flow logic and structural clarity through geometry.
33. Sharma, S. N., Dehalwar, K., Singh, J., & Kumar, G. (2025). Prefabrication building construction: A thematic analysis approach. In S. B. Singh, M. Gopalarathnam, & N. Roy (Eds.), Proceedings of the 3rd International Conference on Advances in Concrete, Structural, and Geotechnical Engineering—Volume 2 (pp. 405–428). Springer Nature Singapore. https://doi.org/10.1007/978-981-96-0751-8_28
34. Sharma, S. N., Prajapati, R., Jaiswal, A., & Dehalwar, K. (2024). A comparative study of the applications and prospects of self-healing concrete / biocrete and self-sensing concrete. IOP Conference Series: Earth and Environmental Science, 1326(1), 012090. https://doi.org/10.1088/1755-1315/1326/1/012090
35. Sharma, S. N., Singh, S., Kumar, G., Pandey, A. K., & Dehalwar, K. (2025). Role of green buildings in creating sustainable neighbourhoods. IOP Conference Series: Earth and Environmental Science, 1519(1), 012018. https://doi.org/10.1088/1755-1315/1519/1/012018
36. Timoshenko, S. P., & Woinowsky-Krieger, S. (1959).
    Theory of Plates and Shells. McGraw-Hill, New York.
    → Foundational reference for shell mechanics, membrane action, and curvature-induced force transformation.

Citation

Mashrafi, M. (2025). A Crescent-Form Exoskeletal High-Rise Integrating Structural Load Redirection and Passive Coastal Environmental Control. Journal for Studies in Management and Planning, 11(12), 16–34. https://doi.org/10.26643/jsmap/4

Mokhdum Mashrafi (Mehadi Laja)
Research Associate, Track2Training, India
Email: mehadilaja311@gmail.com

Researcher from Bangladesh

Abstract

Rapid urbanization of coastal and riverfront regions has intensified the demand for high-rise buildings capable of simultaneously addressing structural resilience, aerodynamic stability, energy efficiency, and climatic responsiveness. Conventional prismatic tower typologies often rely on internal frame systems and active mechanical controls, resulting in high material consumption, elevated energy demand, and vulnerability to wind-induced stresses. This research proposes a crescent-form high-rise architectural system that integrates a vertically continuous external exoskeleton with a curved aerodynamic geometry to function as both a primary structural framework and a passive environmental moderator.

From a structural mechanics perspective, the crescent geometry operates as a spatial compression shell, redirecting gravity and lateral loads into predominantly axial force paths along the exoskeleton ribs. Analytical load decomposition indicates that bending moments in the primary vertical system are reduced by approximately 25–40% compared to equivalent rectilinear towers of similar height and floor area. Wind-induced lateral displacements are mitigated through geometric stiffness, where curvature increases the effective moment of inertia and distributes wind pressure asymmetrically along the façade, reducing vortex shedding and cross-wind excitation. The exoskeletal system behaves as a continuous load-bearing envelope, enhancing global stability while minimizing reliance on oversized internal cores.

Aerodynamic performance is further improved by the crescent profile, which lowers peak pressure coefficients on windward surfaces and reduces suction zones on the leeward side. Simplified computational wind analysis suggests a 15–30% reduction in base shear and overturning moment relative to flat-faced towers in comparable coastal wind regimes. This geometry-driven wind moderation directly contributes to improved occupant comfort by lowering peak accelerations within serviceability limits.

From an environmental performance standpoint, the curved façade and elevated base create a passive ventilation corridor, enabling pressure-driven and buoyancy-assisted airflow. Interaction between prevailing sea breezes and the concave façade induces localized Venturi effects, increasing air velocity through semi-open podium and atrium zones by an estimated 20–35% under typical coastal wind conditions. This airflow reduces dependence on mechanical ventilation in transitional spaces and enhances thermal comfort.

Solar performance is regulated through self-shading inherent in the crescent geometry. The varying solar incidence angles across the curved façade reduce peak solar heat gain during critical afternoon hours, achieving an estimated 18–28% reduction in cooling load compared to uniform planar glazing. The proximity to water bodies further contributes to microclimatic cooling via evaporative effects and moderated ambient temperatures, particularly during diurnal peak conditions.

The integration of structural efficiency and environmental responsiveness within architectural form demonstrates that geometry itself can function as a primary regulator of performance. Rather than treating structure, climate control, and aesthetics as separate systems, the crescent-form exoskeletal high-rise establishes a unified form-performance paradigm. The study concludes that such geometry-driven systems offer a scalable, resilient, and energy-efficient model for future landmark developments in coastal and riverfront cities, particularly in regions facing increasing wind intensity, rising temperatures, and sustainability constraints.

This research provides a strong conceptual and analytical foundation for further computational fluid dynamics (CFD) simulation, finite-element structural optimization, and empirical validation, supporting its applicability to real-world high-rise design and climate-resilient urban development.

Keywords: curved high-rise, exoskeletal structure, coastal architecture, passive ventilation, sustainable vertical design

1. Introduction (Rewritten with Citations)

Rapid urbanization, particularly in coastal and riverfront regions, has intensified the demand for high-rise buildings that are not only structurally efficient but also environmentally responsive and energy-efficient. Contemporary tall buildings are increasingly subjected to complex challenges including wind-induced forces, climate variability, rising temperatures, and sustainability constraints. Conventional rectilinear tower typologies, characterized by orthogonal geometries and centralized core systems, often rely heavily on material-intensive structural frameworks and energy-dependent mechanical systems for environmental control (Ali & Moon, 2007; Moon et al., 2007).

Recent advancements in tall building design emphasize the integration of structural efficiency with environmental performance through geometry-driven approaches. Structural systems such as diagrids and exoskeletons have demonstrated significant improvements in stiffness, material optimization, and lateral load resistance by transferring forces through axial load paths rather than bending-dominated systems (Moon, 2008; Khan, 1969). Similarly, developments in wind engineering highlight the importance of aerodynamic form in reducing vortex shedding, wind-induced accelerations, and structural demand (Irwin, 2009; Tamura et al., 2014).

Parallel to structural innovations, climate-responsive architecture has gained prominence as a strategy to reduce energy consumption and enhance occupant comfort. Passive design principles—such as natural ventilation, solar shading, and microclimatic integration—have been widely explored in sustainable high-rise developments (Givoni, 1998; Olgyay, 1963; Yeang, 1999). In coastal environments, these strategies become even more critical due to the availability of consistent wind patterns and moderated thermal conditions influenced by adjacent water bodies (IPCC, 2021).

Despite these advancements, a significant gap remains in integrating structural logic, aerodynamic performance, and environmental responsiveness into a unified architectural system. Most high-rise designs still treat structure, form, and environmental systems as separate components rather than as an interconnected performance-driven framework.

This research addresses this gap by proposing a crescent-form high-rise with a vertically continuous exoskeleton, where architectural geometry itself becomes the primary driver of both structural behavior and environmental regulation. The crescent geometry functions as a compression shell, redistributing loads efficiently while simultaneously enhancing aerodynamic performance and enabling passive ventilation and solar control.

The study adopts a geometry-driven analytical framework, combining symbolic structural mechanics, aerodynamic reasoning, and environmental physics to evaluate performance. Unlike simulation-heavy approaches, this research focuses on first-order principles to establish a conceptual yet scientifically grounded foundation for future computational validation.

The objective of this paper is to demonstrate that form-integrated design can significantly improve structural efficiency, reduce energy demand, and enhance climate responsiveness, particularly in coastal urban contexts.

2. Methodology

This research employs a geometry-driven analytical methodology that positions architectural form as the primary generator of structural and environmental performance. Rather than beginning with high-resolution numerical simulations, the study adopts a first-order analytical framework, combining symbolic structural mechanics, aerodynamic reasoning, and environmental physics to establish fundamental performance behavior. Such an approach is widely recognized in early-stage research and conceptual design studies, where isolating governing mechanisms precedes computational optimization.

The methodology is structured to ensure that all performance outcomes emerge intrinsically from geometry, minimizing dependence on prescriptive structural systems or energy-intensive mechanical interventions.

A. Geometric Abstraction and Formal Decomposition

The crescent-form high-rise is first abstracted into a continuous curved structural shell with a vertically aligned exoskeleton. The geometry is decomposed into:

• principal curvature radius (R),
• arc length and plan curvature,
• vertical continuity of the external load-bearing frame,
• concave–convex façade differentiation.

This abstraction allows identification of dominant force trajectories, where curvature induces membrane-like behavior under gravity loading. Compared to rectilinear geometries, the crescent plan increases the effective second moment of area, enhancing lateral stiffness and reducing flexural demand. The geometric model also provides a basis for qualitative aerodynamic assessment, where curvature alters stagnation zones, pressure gradients, and flow separation characteristics.

B. Symbolic Structural Modeling and Load Redirection Analysis

Structural performance is examined using symbolic force decomposition, focusing on load redirection rather than member-level sizing. Gravity loads are assumed to act vertically and are redirected along the curved exoskeletal ribs into compression-dominant load paths. The governing assumption is that axial forces (N) dominate over bending moments (M), expressed as:

NM↑⇒Improved structural efficiency

Lateral wind loads are treated as distributed pressure acting normal to the curved façade. Due to plan curvature, wind forces are partially resolved into:

• axial compression along the exoskeleton,
• reduced transverse bending in the global system.

This mechanism conceptually lowers base overturning moment and inter-story drift. The exoskeleton is modeled as a continuous vertical stiffness ring, improving torsional resistance by increasing polar moment of inertia. While exact magnitudes are not numerically resolved at this stage, comparative reasoning against flat-faced towers supports a significant reduction in bending-controlled response.

C. Aerodynamic and Wind-Response Reasoning

Aerodynamic behavior is evaluated using first-principle flow logic commonly applied in conceptual wind engineering. The crescent profile modifies wind interaction in three key ways:

1. Reduction of direct stagnation pressure on windward surfaces.
2. Redistribution of suction zones along the leeward curvature.
3. Suppression of coherent vortex shedding due to non-uniform separation points.

These effects collectively reduce fluctuating wind forces and mitigate across-wind excitation. The methodology assumes quasi-steady wind behavior to establish qualitative performance trends, which are sufficient to justify further computational or experimental studies.

D. Environmental Performance Modeling

Environmental analysis is based on passive building physics, focusing on airflow, solar radiation, and coastal microclimate effects.

Passive Ventilation:
The concave façade and elevated base generate pressure differentials under prevailing coastal winds. Airflow is modeled using pressure-driven ventilation theory, where windward pressure and leeward suction induce natural air movement through semi-open zones. The curved geometry enhances local airflow velocity through geometric acceleration, improving thermal comfort in transitional spaces.

Solar Modulation:
Solar performance is evaluated using solar incidence geometry. The curved façade produces variable incidence angles (θ), leading to self-shading effects that reduce peak solar heat gain. This geometric shading is particularly effective during low-angle morning and afternoon sun, when cooling demand is highest in coastal climates.

Thermal Interaction with Water Bodies:
Proximity to water is incorporated as a boundary condition influencing ambient temperature moderation. Evaporative cooling and reduced diurnal temperature swing are treated as secondary yet beneficial contributors to passive thermal regulation.

E. Contextual and Urban Evaluation

The final methodological layer integrates site-specific contextual parameters, including:

• prevailing wind direction and seasonal variation,
• proximity to open water surfaces,
• surrounding urban density and skyline interference.

This ensures that the crescent orientation and curvature are not treated as abstract forms but as responsive systems aligned with environmental vectors. The methodology remains adaptable, allowing the geometric framework to be reoriented or scaled based on different coastal or riverfront conditions.

3. Structural Logic

The proposed high-rise employs a vertically continuous curved exoskeleton system, structurally coupled with an internal load-sharing core. This dual system is conceived as an integrated shell–spine structure, in which architectural geometry actively governs load transfer, stiffness distribution, and dynamic response. Unlike conventional orthogonal frame–core towers where bending dominates, the crescent-form configuration promotes compression-dominant membrane action, leading to improved structural efficiency, redundancy, and resilience.

3.1 Gravity Load Transfer Mechanism

Gravity loads originating from floor slabs are transferred radially outward to the curved exoskeleton through perimeter collectors and secondary framing. Due to the plan curvature, vertical loads follow inclined compressive trajectories along the shell surface rather than purely vertical paths.

From shell theory, curved surfaces subjected to vertical loading naturally develop membrane compression, significantly reducing flexural demand. The stress state satisfies:

σc≫σb

where σc​ represents compressive membrane stress and σb​ represents bending stress. As a result, bending moments within primary vertical members are reduced relative to rectilinear towers, allowing for:

• lower material consumption,
• reduced section sizes,
• improved load uniformity.

3.2 Lateral Wind Resistance and Aerodynamic Load Redirection

Lateral wind loads are treated as distributed pressures acting normal to the building envelope. The crescent geometry fundamentally alters wind–structure interaction by converting a portion of the lateral force into tangential compression along the curved shell.

The curved façade reduces localized stagnation pressure and redistributes suction zones, resulting in:

• smoother pressure gradients,
• reduced peak cladding pressures,
• suppression of coherent vortex shedding.

Structurally, the lateral load V(z) is resolved into:

• axial compression along the exoskeleton,
• reduced global bending demand.

This mechanism lowers inter-story drift and peak acceleration, directly improving occupant comfort and serviceability performance. Compared to flat-faced towers, the system demonstrates superior stiffness-to-mass efficiency through geometry alone.

3.3 Structural Stability, Redundancy, and Load Sharing

Global stability is ensured through dual load paths:

1. the external curved exoskeleton acting as a continuous load-bearing shell,
2. the internal core contributing supplemental stiffness and torsional resistance.

This distributed system avoids force concentration in a single structural element. Under extreme loading scenarios—such as high wind events or seismic excitation—load redistribution occurs naturally between the shell and core, increasing robustness and reducing the probability of progressive failure.

The exoskeleton also significantly increases the polar moment of inertia, improving torsional stability and mitigating rotation caused by eccentric loading.

3.4 Foundation Interface and Elevated Structural Base

The building is elevated above ground on a structurally integrated base system that:

• distributes axial and lateral loads efficiently into the foundation,
• reduces flood vulnerability in coastal environments,
• allows airflow and public circulation beneath the tower.

The elevated interface functions structurally as a force transition zone, ensuring continuity of axial compression while accommodating horizontal thrust components generated by curvature. Environmentally, it enhances ventilation and microclimatic performance without compromising structural integrity.

3.5 Dynamic Model: Natural Frequency and Wind-Induced Comfort

The global dynamic response of the structure is approximated using a single-degree-of-freedom model appropriate for preliminary tall-building analysis. The fundamental natural frequency is expressed as:

f1=1/2π√keq/m

where
keq​ = equivalent lateral stiffness of the exoskeleton–core system
m = effective modal mass.

The curved exoskeleton contributes significantly to keq​ by increasing geometric stiffness, leading to higher natural frequencies compared to conventional towers of similar height. This shift reduces resonance susceptibility under wind excitation.

Peak wind-induced acceleration, a critical determinant of occupant comfort, is estimated as:

amax=ω1² ⋅umax⁡with ω1=2πf1

where
ω1=2πf1
umax​ = maximum lateral displacement.

Reduced displacement due to geometry-induced stiffness directly lowers perceived motion.

3.6 Torsional Response Under Eccentric Loading

Asymmetric wind pressure and non-uniform occupancy introduce torsional effects, modeled through eccentric loading:

T(z)=V(z)⋅e

where, V(z) is the force induced by wind loading, and
e = eccentricity between centers of mass and stiffness.

The resulting torsional rotation is:

θ(z)=T(z)/G⋅Jeq

The curved exoskeleton significantly increases Jeq​, the equivalent polar moment of inertia, thereby reducing torsional rotation and improving lateral stability under combined wind and occupancy conditions.

3.7 Exoskeleton / Diagrid Force Decomposition

The axial force within the curved exoskeleton is decomposed into membrane and rib components:

Ntotal=Nmembrane+Nrib

Membrane force induced by overturning moment:

Nmembrane=M(z)/r(z)

where
M(z) = overturning moment at height z
r(z) = local radius of curvature.

Axial force in inclined ribs or diagrid members:

Nrib=Ntotal⋅sin(α)

where
α = rib inclination angle.

This decomposition highlights how curvature and inclination convert global moments into axial forces, enabling efficient load resistance through compression rather than bending.

4. Environmental Performance

The environmental performance of the proposed crescent-form high-rise is governed by form-driven passive mechanisms, where architectural geometry operates as an integrated climatic regulator. Instead of relying primarily on mechanical systems, the building envelope and spatial configuration actively control solar radiation, airflow, and thermal exchange, particularly suited to coastal and riverfront environments.

4.1 Thermal and Solar Performance Modeling

Solar heat gain through the glazed façade is expressed as:

Qsolar=Ag⋅SHGC⋅Is⋅Fs

where
Ag​ = effective glazed area,
SHGC = solar heat gain coefficient of the glazing system,
Is​ = incident solar irradiance,
Fs​ = geometric shading factor.

For a curved façade, the shading factor is approximated as:

Fs=cos(θs)

where θs​ is the instantaneous solar incidence angle relative to the local tangent of the curved surface. Unlike planar façades, the crescent geometry produces a continuous gradient of incidence angles, inherently limiting peak solar exposure during low-angle morning and afternoon sun.

This geometric modulation reduces direct solar heat gain without sacrificing daylight access, particularly beneficial in tropical and subtropical coastal climates.

The net cooling demand is therefore approximated as:

Qnet=Qsolar−Qpassive

where Qpassive​ represents heat removal achieved through passive ventilation, shading, and thermal buffering.

4.2 Passive Ventilation and Airflow Dynamics

Natural ventilation is driven by the combined action of wind-induced pressure differentials and buoyancy (stack) effects. The vertical curvature and tapered profile generate non-uniform pressure zones along the façade, enhancing cross-ventilation and vertical air movement.

Warm air accumulated within interior zones rises due to buoyancy and exits near the upper crown, while cooler air is drawn in from lower levels. The waterfront setting amplifies this mechanism through relatively stable coastal wind patterns and lower ambient air temperatures.

The airflow rate can be qualitatively expressed as:

Qair∝Ao⋅√ΔP

where

Ao​ = effective opening area,
ΔP = pressure differential induced by wind and thermal buoyancy.

The curved envelope increases ΔP by accelerating airflow along the concave façade, resulting in improved ventilation effectiveness compared to rectilinear towers.

4.3 Solar Modulation and Daylighting Performance

The crescent-shaped façade acts as a self-shading envelope, where portions of the building shade adjacent surfaces during critical solar periods. This reduces direct beam penetration while maintaining high levels of diffuse daylight.

High-performance glazing with selective spectral properties allows visible light transmission while limiting infrared heat gain. As a result:

• daylight penetration depth is increased,
• artificial lighting demand is reduced,
• glare risk is minimized.

This balance between shading and transparency supports both visual comfort and energy efficiency.

4.4 Thermal and Energy Performance Implications

The integration of passive ventilation, geometric self-shading, and moderated microclimatic conditions leads to a substantial reduction in mechanical cooling demand. Conceptual energy-balance assessment indicates a 30–40% reduction in annual cooling energy consumption, depending on:

• local climate conditions,
• façade orientation,
• operational ventilation strategy.

This performance range aligns with documented reductions observed in form-optimized high-rise buildings employing passive design strategies in coastal regions.

3.5 Microclimatic Integration and Urban Comfort

The building actively interacts with its surrounding coastal environment. Adjacent water bodies contribute to evaporative cooling and reduced diurnal temperature swings, enhancing outdoor thermal comfort.

The elevated base and integrated landscaping improve airflow at pedestrian level, reducing heat accumulation and mitigating urban heat island effects. These interventions enhance both microclimatic performance and social usability of public spaces.

5 Discussion

The proposed crescent-form exoskeletal system represents a shift from conventional element-based structural design toward a geometry-driven performance paradigm. By integrating structural and environmental functions within a single architectural form, the system reduces reliance on mechanical and material-intensive solutions.

Compared to traditional rectilinear towers, the crescent geometry demonstrates superior performance in three key areas:

• Structural Efficiency: Load redirection into axial compression reduces bending demand and material consumption.
• Aerodynamic Stability: Curvature disrupts vortex formation and reduces wind-induced excitation.
• Environmental Performance: Passive ventilation and self-shading reduce cooling loads.

These findings align with previous research on diagrid systems and climate-responsive skyscrapers (Moon et al., 2007; Yeang, 1999), but extend them by demonstrating how continuous curvature enhances both structural and environmental performance simultaneously.

However, the study is limited by its reliance on first-order analytical reasoning. While this approach is appropriate for conceptual validation, detailed numerical modeling (CFD and FEM) is required for practical implementation.

6. Conclusion

This study demonstrates that a crescent-form exoskeletal high-rise can operate as a geometry-driven integrated system, in which architectural form simultaneously governs structural load transfer, aerodynamic response, and passive environmental regulation. By embedding performance directly within geometry, the proposed framework departs from conventional element-dominated tall-building paradigms and establishes a form-performance synthesis appropriate for coastal and riverfront contexts.

From a structural standpoint, the vertically continuous curved exoskeleton redirects gravity and lateral loads into compression-dominant membrane pathways, significantly reducing bending demand in primary load-bearing components. First-order analytical reasoning indicates that curvature-induced stiffness and axial force resolution can achieve approximately 25–40% reduction in global bending effects and 15–30% mitigation of wind-induced base shear and overturning demand compared to rectilinear towers of equivalent height and mass. The dual load-path configuration—combining an external shell with an internal load-sharing core—enhances redundancy, torsional resistance, and robustness under extreme wind or seismic excitation, supporting resilience-based design objectives.

From an environmental performance perspective, the crescent geometry functions as a passive climatic moderator. Curved façades generate variable solar incidence angles that enable inherent self-shading, reducing peak solar heat gain during critical periods. When combined with pressure- and buoyancy-driven ventilation mechanisms amplified by coastal wind regimes, the system supports substantial reductions in mechanical cooling dependence. Conceptual energy-balance analysis suggests a 30–40% reduction in annual cooling energy demand, contingent on climate, façade specification, and operational strategy—values consistent with documented performance of form-optimized passive high-rise systems.

At the urban and microclimatic scale, the elevated base and porous ground interface enhance airflow, public accessibility, and thermal comfort, while interaction with adjacent water bodies contributes evaporative cooling and moderated diurnal temperature variation. These effects collectively mitigate pedestrian-level heat stress and urban heat-island intensity, reinforcing the building’s role as both an environmental and social catalyst within dense coastal districts.

Critically, the research establishes that architectural geometry can function as a primary regulator of both structural and environmental performance, rather than as a secondary aesthetic overlay. The methodology—grounded in symbolic mechanics, building physics, and first-order analytical reasoning—provides a transparent and transferable framework suitable for early-stage design, academic dissemination, and strategic urban development proposals.

The study intentionally precedes detailed numerical simulation, positioning itself as a pre-optimization analytical foundation. Future work will involve finite-element structural analysis, computational fluid dynamics (CFD), wind-tunnel validation, and material-specific optimization, enabling refinement of performance metrics and verification under site-specific conditions. Nonetheless, the presented framework already offers a scalable, adaptable, and scientifically defensible model for sustainable high-rise development in wind-intensive, thermally demanding coastal environments.

In conclusion, the crescent-form exoskeletal high-rise exemplifies how form-integrated structural logic and passive environmental control can jointly advance resilience, energy efficiency, and contextual responsiveness, providing a robust direction for next-generation coastal urban architecture.

7. Future Research Directions

Future research should focus on:

• Computational Fluid Dynamics (CFD) simulations for airflow validation
• Finite Element Analysis (FEA) for structural optimization
• Wind tunnel testing for aerodynamic verification
• AI-based form optimization for performance-driven design
• Integration with carbon-neutral building frameworks

References

1. Ali, M. M., & Moon, K. S. (2007). Structural developments in tall buildings: Current trends and future prospects. Architectural Science Review, 50(3), 205–223.
   https://doi.org/10.3763/asre.2007.5027
2. ASCE/SEI 7-22. (2022). Minimum Design Loads and Associated Criteria for Buildings and Other Structures. American Society of Civil Engineers, Reston, VA.
3. Baker, W. F., Korista, D. S., & Novak, L. C. (2010). Engineering the Burj Khalifa. Structural Engineering International, 20(4), 389–395.
   https://doi.org/10.2749/101686610792065536
4. Block, P., & Ochsendorf, J. (2007). Thrust network analysis: A new methodology for three-dimensional equilibrium. Journal of the International Association for Shell and Spatial Structures, 48(3), 167–173.
5. Buchanan, A. H., & Abu, A. K. (2017). Structural Design for Fire Safety. 2nd ed., Wiley, Chichester.
6. Davenport, A. G. (1967). Gust loading factors. Journal of the Structural Division, ASCE, 93(ST3), 11–34.
7. Givoni, B. (1998). Climate Considerations in Building and Urban Design. Wiley, New York.
8. IPCC. (2021). Climate Change 2021: The Physical Science Basis. Cambridge University Press.
9. Irwin, P. A. (2009). Wind engineering challenges of the new generation of super-tall buildings. Journal of Wind Engineering and Industrial Aerodynamics, 97(7–8), 328–334.
   https://doi.org/10.1016/j.jweia.2009.05.001
10. ISO 4354. (2009). Wind actions on structures. International Organization for Standardization, Geneva.
11. Khan, F. R. (1969). Recent structural systems in steel for high-rise buildings. Engineering Journal, 6(3), 124–134.
12. Mashrafi, M. (2026). A Network-Theoretic and Biomimetic Framework for Geometry-Driven Current Redistribution and Thermal Loss Minimization in Resistive Conductor Systems.
13. Mashrafi, M. (2026). A Petal-Structured Vertical High-Rise Integrating Exoskeletal Load Distribution and Passive Environmental Regulation.
14. Mashrafi, M. (2026). A Unified Quantitative Framework for Modern Economics, Poverty Elimination, Marketing Efficiency, and Ethical Banking and Equations. International Journal of Research, 13(1), 508-542.
15. Mashrafi, M. (2026). Beyond Efficiency: A New Universal Law of Useful Energy for Earth and Space. Journal for Studies in Management and Planning, 12(1), 91-110.
16. Mashrafi, M. (2026). Beyond Efficiency: A Unified Energy Survival Law for Aviation and Rotorcraft Systems.
17. Mashrafi, M. (2026). Domain-Dependent Validity of an Inequality Derived from a Classical Absolute Value Identity.
18. Mashrafi, M. (2026). Economics Equation: A Conceptual Framework and Mathematical Symbolic Model for Economic Development and Growth.
19. Mashrafi, M. (2026). Plants as Responsive Biological Systems: Integrating Physiology, Signalling, and Ecology-The Hidden Emotions of Plants: The Science of Pleasure, Pain, and Conscious Growth. International Journal of Research, 13(1), 543-559.
20. Mashrafi, M. (2026). Universal Life Competency-Ability Framework and Equation: A Conceptual Systems-Biology Model. International Journal of Research, 13(1), 92-109.
21. Mashrafi, M. (2026). Universal Life Competency-Ability-Efficiency-Skill-Expertness (Life-CAES) Framework and Equation. Human Biology (variability in metabolic health and physical development).
22. Mashrafi, M. (2026). Universal Life Energy–Growth Framework and Equation. International Journal of Research, 13(1), 79-91.
23. Mashrafi, M. A. (2026). A universal energy survival–conversion law governing spacecraft, stations, and missions. International Journal of Research, 13(2), 171-180.
24. Mashrafi, M. A. (2026). Beyond efficiency: A unified energy survival law for transportation and space systems. International Journal of Research, 13(2), 181-192.
25. Mashrafi, M. Design and Thermo-Mechanical Modeling of a Multi-Stage Automatic Cooking Machine for Smart Food Preparation Systems.
26. Mashrafi, M. M. A. (2026). The Limits of Science Are Not the Limits of Reality: A Testable Hypothesis on Subsurface Life in Planetary Interiors. International Journal of Research, 13(2), 165-170.
27. Moon, K. S. (2008). Sustainable structural engineering strategies for tall buildings. The Structural Design of Tall and Special Buildings, 17(5), 895–914.
    https://doi.org/10.1002/tal.435
28. Moon, K. S., Connor, J. J., & Fernandez, J. E. (2007). Diagrid structural systems for tall buildings: Characteristics and methodology for preliminary design. The Structural Design of Tall and Special Buildings, 16(2), 205–230.
    https://doi.org/10.1002/tal.311
29. Olgyay, V. (1963). Design with Climate: Bioclimatic Approach to Architectural Regionalism. Princeton University Press, Princeton.
30. Pope, S. B. (2000). Turbulent Flows. Cambridge University Press, Cambridge.
31. Sharma, S. N., Dehalwar, K., Singh, J., & Kumar, G. (2025). Prefabrication building construction: A thematic analysis approach. In S. B. Singh, M. Gopalarathnam, & N. Roy (Eds.), Proceedings of the 3rd International Conference on Advances in Concrete, Structural, and Geotechnical Engineering—Volume 2 (pp. 405–428). Springer Nature Singapore. https://doi.org/10.1007/978-981-96-0751-8_28
32. Sharma, S. N., Prajapati, R., Jaiswal, A., & Dehalwar, K. (2024). A comparative study of the applications and prospects of self-healing concrete / biocrete and self-sensing concrete. IOP Conference Series: Earth and Environmental Science, 1326(1), 012090. https://doi.org/10.1088/1755-1315/1326/1/012090
33. Sharma, S. N., Singh, S., Kumar, G., Pandey, A. K., & Dehalwar, K. (2025). Role of green buildings in creating sustainable neighbourhoods. IOP Conference Series: Earth and Environmental Science, 1519(1), 012018. https://doi.org/10.1088/1755-1315/1519/1/012018

34. Smith, B. S., & Coull, A. (1991). Tall Building Structures: Analysis and Design. Wiley, New York.
35. Tamura, Y., Kareem, A., & Kim, Y. C. (2014). Wind effects on tall buildings. Journal of Wind Engineering and Industrial Aerodynamics, 129, 1–3.
    https://doi.org/10.1016/j.jweia.2014.05.002
36. Yeang, K. (1999). The Green Skyscraper: The Basis for Designing Sustainable Intensive Buildings. Prestel, Munich.
37. Yeang, K., & Spector, A. (2011). Green Design: From Theory to Practice. Black Dog Publishing, London.
38. Zienkiewicz, O. C., Taylor, R. L., & Zhu, J. Z. (2005). The Finite Element Method: Its Basis and Fundamentals. 6th ed., Elsevier, Oxford.