Seismic Behavior Comparion And Collapse Mechanism Analysis Of Multi-story Masonry Structure With First Story Used As Shops

A large number of Multi-story masonry buildings with first story used as shopsexist in small and medium-sized cities in south of China. This kind of buildings have ahigh collapse rate and will cause a lot of loss once it collapses. The seismic situation issevere. Earthquake damage investigation points out that most of Multi-story masonrybuildings with first story used as shops collapsed in the longitudinal direction and theframe columns are used as the bearing members and anti-literal force members in thefirst longitudinal wall. The first longitudinal wall of remaining buildings is made up ofconcrete column and wing wall. For example, staff apartment block of BeichuanTelecommunication Bureau, only suffered moderate damage in Wenchuan earthquake.So it is important to make a comparision between two models in seismic performanceand analyze the collapse mechanism of multi-story masonry buildings with first storyused as shops.Taking staff apartment block of Beichuan Telecommunication Bureau as theprototype structure, the thesis mainly makes a comparision between two models inseismic performance by the shaking table testing, studys the three longitudinal walls,mechanical properties by pseudo-static testing and summarizes the collapse mechanismof multi-story masonry buildings with first story used as shops. The main results are asfollows:1) This chapter analyzes the reasons of earthquake damage to the multi-storymasonry structure and the multi-story masonry structure with frame in lower storiesdeeply and summarizes earthquake damage that were caused by violating the principleof seismic concept design of buildings and propose improvement measures.2) The shaking table testing of two models shows that the seismic performance ofthe model structure with wing wall is better than that of the model structure withoutwing wall in terms of the test phenomenon, displacement response and the lateralstiffness ratio.3) The researchers obtain bearing capacity, stiffness, deformation of the threelongitudinal walls of the model structure with wing wall by pseudo-static testing. Thestiffness of the pure frame of the model structure without wing wall was obtained bycalculation. All those lay the foundation for summarizing the collapse mechanism ofthe model structure without wing wall.4) The collapse testing shows that the collapse of the model structure withoutwing wall has four steps, which contains cracks appearance, cracks extension, thevertical walls fall by pieces and cracks of horizontal walls extension. 5) Studying the mechanical properties of three longitudinal walls proves that thethree longitudinal walls failed to develop horizontal resisting force because of themismatch of stiffness and ductility which lead to be damaged one by one.