Experimental Study And Analysis On Seismic Performance Of Multi-story Brick Structures With Bottom-frame Designed By Two Different Versions Of Codes

The multi-story brick structures with bottom-frame are widely used in small and medium-sized towns in China.The bottom of this kind of structure is a frame layer,which can be used for commercial purposes of large bay,and the upper masonry layer can be used as a residential or office building.In recent years,earthquake damage shows that the failure modes of multi-story brick structures with bottom-frame designed by two different versions of codes are different.In order to clarify the difference between the failure mode and the seismic performance of the multi-story brick structures with bottom-frame designed by two different versions of codes,the seismic shaking table test and numerical simulation analysis are carried out in this paper.The main work done in this paper is as follows:(1)The earthquake damage phenomena of the multi-story brick structures with bottom-frame built in different periods are summarized.The failure mode of the multistory brick structures with bottom-frame is preliminarily understood,and the cause of failure is analyzed,mainly the relation between the failure mode and lateral stiffness ratio.The research status of seismic performance of those is reviewed.(2)Two multi-story brick structures with bottom-frame are designed by "code for seismic design of buildings GB50011-2010" or 10 code for short and "code for seismic design of buildings GBJ11-89" or 89 code for short,and two shaking table test models are made according to the scale of 1/5,the seismic performance tests on the multi-story brick structures with bottom-frame designed by two different versions of code are completed.The failure mode and seismic performance of two models are studied?(3)The experimental phenomena and experimental data of the two models are analyzed and compared in detail,and their failure modes and failure mechanisms are studied.The results show that the failure of the model designed by the 89 code first appears in the bottom frame layer,and with the increase of the amplitude of the ground motion,the damage is still mainly concentrated in the bottom frame layer,while the upper masonry layer is basically intact.The failure of the multi-story brick structures with bottom-frame according to the 10 code first appears in the transition masonry layer,and then develops the bottom frame layer.In addition,under the same level of rare earthquake,The damages of the multi-story brick structures with bottom-frame designed according to the 10 code is lighter than the model designed according to the 89 code,and the seismic performance is greatly improved.(4)Using the solid element in the ABAQUS finite element software,the analysis models of the two multi-story brick structures with bottom-frame are established respectively,and the elastoplastic time history analysis under the earthquakes is carried out.Taking the maximum interlayer displacement angle as the failure index,the failure modes of the structure are analyzed and compared with the test results and the test phenomena.The results show that the simulation results are similar to the experimental results,and the validity of the analysis model is verified.The modeling method provides an analytical method for the study of the failure mode of the multi-story brick structures with bottom-frame.