Designing For Seismic Events – A Case Study

Frances Badelow and Simon Cloherty

This paper presents a case study of the seismic design for a multi-level car park constructed over soft Holocene alluvial deposits in Brisbane. The paper presents the design approach and the structural and geotechnical analysis undertaken to assess the earthquake induced impacts on the structure to demonstrate the adequacy of the proposed foundation design.

The paper highlights the following design aspects:

  1. The requirements of Clause 5.2.2 of the Australian Standards AS1170.4:2007 to provide tie beams may not be appropriate in all cases.
  2. The use of elastic response spectrum analysis using modal superposition methods can result in refined inertia forces on the foundation compared to those computed using pseudo-static methods.
  3. The earthquake-induced kinematic effect should not be overlooked with respect to total deformation of the foundation.