Effect Analysis Of Infilled Wall On The Seismic Performance Of Reinforced Concrete Frame Structure

Frame structure with infilled walls is a bearing system usually used in multi-storied buildings and high-rise buildings currently.The interaction between frame and infilled wall is complex when the structure is under horizontal load.So the analysis about the anti-seismic effect of frame structure with infilled walls is very difficult and lengthy.Although many scholars have done much research and got many precious results on frame structure with infilled walls, on the whole there are still many problems to solve. This paper has mainly done the following research work:1.Based on the previous research, this paper expounded the interaction between frame and infilled wall when frame structure with infilled walls is under horizontal load,which contains the effect of frame on infilled wall and the effect of infilled wall on frame. Frame has the constraint function to infilled wall,which can greatly improve the resistance capability and the deformation performance of infilled wall when it is under horizontal load. Infilled wall not only has advantageous effect,but also has disadvantageous effect.2.This paper discussed two methods of structural nonlinear seismic response analysis,which are elastic-plastic time history analysis procedure and static elasto-plastic analysis (Pushover analysis) procedure. This paper made comprehensive comparison between the two methods and finally determined the seismic response analysis method of the frame structure with infilled walls in the article,which is static elasto-plastic analysis procedure.3.Based on the discussion about the failure modes of infilled wall under horizontal earthquake effect and the quality evaluation to the existing simplified models of infilled wall, this paper put forward a more reasonable simplified model—cross spring supporting model. Infilled wall is simplified to be cross link spring elements in this model.When the infilled wall has holes, hole stiffness influence parameter is raised to cut the wall stiffness. With the help of the finite element analysis software SAP2000 and the existing test data,the simplified model and the simplified calculation formula about hole stiffness influence parameter are proved to be reasonable and effective.4.This paper established the five layers framework with infilled walls model and the pure frame model,and worked at the earthquake response analysis to a plane framework separately from the two models,which is based on the cross spring supporting simplified model mentioned previously and the structure analysis software SAP2000. Through the analysis,this paper compared the natural vibration periods,the displacements and the interlayer shears of the two models. Analysis results show that the vibration period adjustment coefficient of the frame with infilled walls in the code is not reasonable,which underestimated the earthquake effect. This paper suggests the vibration period adjustment coefficient should be 0.5～0.6 to the framework with more and uniform distributed infilled walls along the height. In addition analysis results further prove that the seismic performances of frame structure with infilled walls,like the bearing capacity,the deformation capacity and so on, are better than pure framework.The results, meanwhile, further prove the disadvantageous effect of infilled wall to framework and point out that the influence of infilled wall should be considered comprehensively and accurately in design.