Seismic Design of Building Basement Structures and Underground Structures

This chapter discusses earthquake-resistant design approaches for common underground structures such as basement walls for buildings, retaining walls, tunnels, boxes constructed by cut-and-cover construction, and shafts. The assessment of seismic hazard, the characterization of underground sites, and performance objectives for structural design are considered. Classical methods for determining the dynamic pressures on walls are presented, along with a description of the numerical methods that are currently available. Simplified methods and numerical modeling techniques for determining the ovaling displacements and design actions for tunnels are also presented. A simplified method for determining the racking deformations and design actions for underground box structures during earthquakes is reviewed, and numerical modeling techniques are discussed. Examples of the design of the basement walls of a tall building using a force-based approach and the proportioning of an underground box structure using a displacement-based technique are presented.