Theoretical Basis of a Structural Strategy for a Modular Steel-Framed Exhibition Pavilion

Modular Prefabrication and Lightweight Steel Framing

The pavilion’s structural strategy capitalizes on modular prefabrication, utilizing light, self-supporting cassettes composed of pressed metal sections with sheathing boards. This approach aligns with principles of modern modular construction, which enhances speed, quality control, and sustainability by transferring significant assembly work off-site (Smith, 2010; Lawson et al., 2014). Lightweight steel framing is especially suitable in temperate climates due to its durability and flexibility, providing both structural strength and ease of transportation and assembly (Kronenburg, 2007). The use of hot-rolled square hollow sections (SHS) as the primary external frame optimizes resistance to axial, bending, and torsional forces while maintaining a slender profile ideal for the tower form (Regan, 2013). The perimeter load transfer mechanism, where vertical loads are taken at module corners and transferred to pad supports at the base, is efficient in minimizing concentrated stresses and enabling foundation adaptability across diverse urban sites (Evans, 2016). This strategy avoids heavy or permanent foundations, critical for temporary urban installations.

Structural Stability Through Combined Module and Frame Interaction

The combination of self-supporting modules stabilized internally by floor diaphragms and infill facade panels, with an external steel frame, exemplifies a hybrid load-resisting system (Hyde, 2000). This synergy between internal module rigidity and external frame bracing: Enhances lateral stability against wind and seismic forces. Distributes loads evenly through the interconnected modules. Provides redundancy by sharing load paths between modules and the frame (Smith, 2010). The external steel frame’s consoles and outriggers play a crucial role in stabilizing the slender tower against overturning moments and lateral displacement, allowing the pavilion to safely interact with its urban context without permanent ground anchoring (Kronenburg, 2007; Petrescu and Trogal, 2017).

Sequence of Assembly and Structural Design for Rapid Deployment

The onsite assembly strategy—building modules piece-by-piece rather than hoisting pre-assembled volumes—favors lighter components, reducing dependency on heavy lifting machinery and enabling more flexible urban deployment (Gibb, 1999). This incremental assembly approach benefits structural design by allowing smaller, manageable steel frame sections to be sequentially connected and stabilized, minimizing risks associated with temporary instability during erection (Lawson et al., 2014). Structurally, this demands robust modular connection details, such as bolted flange joints or mechanical fasteners, designed to allow multiple assembly cycles without degradation and to ensure precise alignment under field conditions (Smith, 2010).

Variations in Structural Configurations and their Design Implications

The three design options presented illustrate important structural design opportunities:

Option 1’s division into three separate frames responding to volumetric differences introduces complexity and additional steelwork due to less efficient load distribution. This necessitates detailed analysis of joint forces and member sizing to avoid redundancy while maintaining modular flexibility (Regan, 2013).

Option 2 consolidates service cores centrally, enabling more regular beam-column grids and prefabricated frame sets, thus reducing steel tonnage and fabrication complexity. This regularity promotes efficiency in structural detailing and simplifies transport logistics (Lawson et al., 2014).

Option 3 creates a nested double-structural layer system, enhancing the overall rigidity and robustness of the tower. This dual frame approach supports not only vertical and lateral loads but also integrates stair and mechanical service frames (‘backpacks’), which act as external bracing elements, increasing torsional resistance and providing opportunities for architectural expression (Kronenburg, 2007).

Integration of Circulation and M&E ‘Backpacks’ as Structural Elements

Attaching prefabricated steel-framed mechanical and electrical (M&E) service units as ‘backpacks’ to the tower’s exterior exemplifies functional structural integration. These units contribute to the building’s lateral load resistance while enabling rapid installation and servicing (Petrescu and Trogal, 2017). Such integration allows the main tower frame to be optimized for pure structural performance, while the external M&E modules serve dual purposes of enclosure and stiffening, reducing the need for additional internal bracing (Zardini, 2005).

Concealed Bracing and Visual Transparency

Cross bracing concealed behind stretched fabric and lift assemblies maintains structural stability while addressing aesthetic and experiential goals. This solution enables: Clear glazed facades on the exhibition sides without intrusive structural elements. Concealed vertical supports to avoid visual clutter and to frame the displayed products effectively. The use of fabric tension systems to conceal bracing also aligns with innovative lightweight design trends where structure and architecture coexist seamlessly (Hyde, 2000; Gehl, 2010).

Structural Considerations for Temporary Urban Installations

The pavilion’s lightweight, demountable steel frame and modular cassettes facilitate its temporary yet resilient presence in variable urban contexts, allowing it to conform to site-specific constraints without permanent foundation works (Evans, 2016). Its capacity to be bolted together on-site mirrors the logic of temporary construction equipment (e.g., cranes), supporting the notion of architecture as an adaptable, transient urban intervention (Bishop and Williams, 2012).

References

Bishop, P. and Williams, L. (2012) The Temporary City. London: Routledge.

Evans, J. (2016) ‘Temporary Urbanism: Alternative Planning and the Creation of a New Urbanism’, Urban Studies, 53(6), pp. 1176–1191.

Gehl, J. (2010) Cities for People. Washington, DC: Island Press.

Gibb, A.G.F. (1999) Off-site Fabrication: Prefabrication, Pre-assembly and Modularisation. Chichester: Wiley-Blackwell.

Hyde, R. (2000) Climate Responsive Design: A Study of Buildings in Moderate and Hot Humid Climates. London: E & FN Spon.

Kronenburg, R. (2007) Flexible: Architecture That Responds to Change. London: Laurence King.

Lawson, R.M., Ogden, R.G. and Bergin, R. (2014) Modular Construction in High-Rise Buildings: Proceedings of the Institution of Civil Engineers. London: ICE Publishing.

Petrescu, D. and Trogal, K. (2017) The Social (Re)Production of Architecture: Politics, Values and Actions in Contemporary Practice. London: Routledge.

Regan, P. (2013) Structural Steel Design. London: Wiley.

Smith, R.E. (2010) Prefab Architecture: A Guide to Modular Design and Construction. Hoboken: Wiley.

Zardini, M. (ed.) (2005) Sense of the City. Montreal: Canadian Centre for Architecture.