What are diaphragm walls commonly used for in construction?

• A. To enhance the thermal insulation of buildings
• B. To prevent excavation walls from collapsing
• C. To provide a decorative finish to the exterior of structures
• D. To support heavy machinery during construction

Answer: (B)

Diaphragm walls are primarily used in construction to provide stability and support for deep excavations, particularly in urban environments where adjacent structures may be at risk of collapse due to soil removal. By using diaphragm walls, engineers create a robust barrier that helps retain soil and groundwater, effectively preventing the collapse of excavation walls during construction activities.

These walls are typically made of reinforced concrete and are installed deep into the ground. Their design allows them to withstand lateral earth pressures and any hydrostatic pressures that may be present, which is crucial during excavation work. This function is particularly important in sites where limited space or close proximity to other buildings makes traditional bracing systems impractical.

The other options do not accurately reflect the primary functions of diaphragm walls. Enhancing thermal insulation aligns more with building envelope materials, decorative finishes relate to aesthetic elements rather than structural support, and supporting heavy machinery pertains to different construction solutions such as foundations or rigs, rather than the role of diaphragm walls.