Experimental Research And Damage Analysis Of Seismic Performance Of The Short-Leg Shear Wall

Short-leg shear wall(in short SLW) is a new type structure form, it is widely used and developed in our country for its reasonable architectural function, mechanical performance and engineering cost. But SLW is seldom applied in earthquake area for lacking deep investigation and strong earthquake test. Technical specification for concrete structures of tall building makes strict requirements of seismic design of SLW for security. Comprehensive experimental research and theoretical analysis of SLW can improve the design theory and the relevant provisions of the Specifications. To achieve the above goals, the following works have been done.Firstly, six 1:2 scale T-shaped and six L-shaped SLW specimens subjected to low cyclic loading are conducted. The influence of axial compression ratio, sectional depth-thickness ratio, shear span ratio to bearing capacity, ductility, hysteretic characteristics, energy dissipation capacity and failure mechanism of SLW are investigated, the applicability of plane section assumption and shear lag effect are also investigated.Secondly, nonlinear finite element analysis to test is conducted to prove reliability of the model. To expand the test results, the influence of axial compression ratio, concrete strength, strength of longitudinal reinforcement, hoop strength to seismic performance of SLW are conducted, some useful design proposals are proposed.Thirdly, by adding the square steel tube to web to make a new structure-steel tube reinforced concrete short-leg shear wall, the structure shows superior seismic performance with nonlinear finite element analysis.Fourthly, restoring force model of SLW member is established, model can be used to conduct elastic-plastic seismic response analysis of SLW for its better reflecting hysteretic characteristics of SLW member.Fifthly, the limit values of axial compression ratio of T shaped SLW are proposed in accordance with stirrup characteristic values, height -width ratio and the expected elastic-plastic displacement angle. Results are listed with the forms of table for design reference.Lastly, the practical damage assessment model is proposed based on theoretical analysis and test data, model provides reference to assess damage of structure. The relationship of performance level, inter-story displacement angle and damage index is established that could be useful to seismic design based on damage performance.