Study On The Influence Of Infill Wall Stiffness Effect On The Seismic Collapse Resistance Of RC Frame Structure

The results of successive earthquakes and studies show that there is an obvious stiffness effect of the infill wall,and the unreasonable arrangement of the infill wall can cause serious local damage to the structure and even lead to the collapse of the structure.In order to study the influence of the stiffness effect of the infill wall on the seismic collapse resistance performance of the RC frame structure,this paper takes the external corridor RC frame structure teaching building with typical earthquake damage in the Wenchuan earthquake Xuankou Middle School as the research object,and explores the mechanism of infill wall stiffness effect on the collapse mechanism of RC frame structure through a combination of experimental research,statistical data fitting and numerical simulation,and provides suggestions for quantifying the stiffness effect of the infill wall in the layout of the structural design.The main work of the thesis is as follows:(1)Based on the collapsed teaching building in Wenchuan Earthquake Xuankou Middle School,designing and completing a 1:4 scaled-down three-story infill wall exterior gallery type RC frame structure for earthquake simulation shaker tests.Based on the test results,analyzing the macroscopic damage and the subsequent collapse process of the test model,explaining the influence of the stiffness effect of the infill wall on the failure mode of the frame structure under strong earthquake,and revealing the collapse mechanism in the earthquake damage of prototype structures,which provides a reference for the conceptual design of collapse resistance of this type of building.(2)This paper reviews the calculation methods of elastic lateral stiffness of infill walls proposed by scholars,sorts out the measured values of lateral stiffness of 36 infill walls at home and abroad,and verifies the accuracy of each calculation method by comparing the theoretical calculated values with the measured values.According to the statistical test data,based on the three factors of block type,mortar compressive strength and wall aspect ratio,giving a recommendation for the calculation methods of lateral stiffness resistance of infill walls in yielding stage and peak bearing capacity stage through data fitting.(3)Based on the teaching building of Xuankou Middle School,designing six infill wall RC frame structure models with different stiffness distribution along each axis of the plane by changing the arrangement of infill walls on the plane while the overall structural stiffness remained basically unchanged.In order to compare and analyze the seismic collapse resistance of each model,conducting IDA analysis of six models and providing data support for how to consider the stiffness effect of the infill wall in the structural design through the quantitative comparison of the stiffness distribution of the infill wall.