Shaking table tests and numerical analysis of an over-track multi-tower building

This article aims to investigate the seismic performance of a four-tower (frame-shear wall) building with a large frame podium at bottom sitting on a metro depot through shaking table test and numerical simulations. Technical problems generally exist in this type of buildings due to irregularity in elevation and plan, tower offset, and structural transfer. These problems bring challenges to engineers when analysing and predicting dynamic responses under earthquakes which is crucial for structural safety. To evaluate the seismic performance of the building, a comprehensive study which includes a shake table test of the scaled model and time history analyses using a finite-element model is conducted. The shake table test model is designed based on the similitude law with a 1:40 scale. The dynamic characteristics, cracking pattern, failure mechanism, as well as maximum acceleration and deformation response are investigated. The corresponding finite-element analysis shows a good agreement with experimental results. It is concluded that this type of building can achieve the predefined performance objectives with well-behaved transfer floors. Shear failure at weak story is considered as a main failure mode of the structure. The whipping effect of stories on the top of structure is remarkable. There is no severe damage in steel reinforced concrete beams. Finally, some design suggestions are also proposed to improve the seismic performance of this type of buildings.