Effects of Nonlinear Soil-Foundation-Structure Interactions on a Multi-Storey Building during Earthquakes

 

Effects of Nonlinear Soil-Foundation-Structure Interactions on a Multi-Storey Building during Earthquakes

 

Mohammad Sarrafzadeh1a, Victoria Shrimpton1b, Ellys Lim2a, Xiaoyang Qin2b and Nawawi Chouw3

 

1Undergraduate Student, Emaila: msar713@aucklanduni.ac.nz, b: vshr001@aucklanduni.ac.nz

 

2PhD candidate, Emaila: elim882@aucklanduni.ac.nz, b: xqin009@aucklanduni.ac.nz

 

3Associate Professor, Email: n.chouw@auckland.ac.nz

 

Department of Civil and Environmental Engineering, University of Auckland, Auckland, New Zealand

 
Abstract
During earthquake events, soil and structural plastic deformation can occur. Previous studies focused mostly on the effects of soil nonlinearity on the seismic response of elastic multi degree-of-freedom (MDOF) systems. However, little work has been done on the combined effect of structural plastic hinge development and nonlinear soil deformation. This study focuses on the response of a multi-storey building with nonlinear soil-foundation-structure interaction (NSFSI), i.e. soil plastic deformation, foundation uplift and plastic hinge development in the structure. The development of bending moments, kinetic energy and induced earthquake energy in the structure were investigated. Experiments were performed on a shake table with a scaled MDOF model. The soil plastic deformation was simulated by placing the structure on sand in a laminar box. Plastic hinge development in the structure was permitted. Response of the model under fixed-based conditions was used as a reference case. The response of the structure with NSFSI was compared to that of its fixed-based counterpart. It was found that the maximum bending moments at the column-foundation connection and the kinetic energy in the structure were reduced when NSFSI was considered.
 
Keywords: Soil-foundation-structure interaction, plastic hinge, plastic soil deformation