Experimental On Seismic Performance Of T-shaped Double Corrugated Steel Plate Concrete Composite Shear Wall

In the super high-rise building,the structure is subjected to the combined action of vertical load and horizontal load,and the effect of horizontal load increases with the increase of height.The rationality and economy of super highrise building structure are closely related to the performance of structure lateral force resistance system.Therefore,it is significant to develop high-performance structural lateral force system.Double steel plate concrete composite shear wall has been widely used in super high-rise buildings.However,the current design code lacks the bearing capacity calculation method of steel plate concrete composite shear wall with special-shaped section,and the theoretical research is relatively lagging behind the engineering application.In view of this situation,a new type of T-shaped double corrugated steel plate concrete composite shear wall with restrained concrete-filled square steel tube column is proposed by using corrugated steel plate with greater lateral stiffness as the outer steel plate of composite shear wall.Based on the low cycle repeated loading test of 10 composite shear walls,combined with theoretical analysis,the failure mechanism is revealed,and the influence law of various parameters on its seismic performance is analyzed,and the bearing capacity calculation formula is proposed,and the restoring capacity model is established.The main research results are as follows:(1)Based on the quasi-static test of composite wall,the failure process and final failure mode of the composite wall under horizontal repeated load are observed.The hysteretic curve,skeleton curve and stress-strain curve are obtained.The seismic performance indexes such as deformation capacity,ductility,stiffness degradation and energy dissipation capacity are studied.The failure mechanism of composite wall under repeated load is revealed,and the influence of various parameters on it is analyzed The influence law of seismic performance.The results show that the bending failure occurs under horizontal repeated load,and the hysteretic curve is asymmetric,which can be divided into tensile failure and compressive bending failure according to the failure characteristics;the average elastic interlaminar displacement angle of the specimens is about 1/156,the average elastic-plastic interlayer displacement angle is 1/43,and the average ductility coefficient is 3.7.The shear walls have good deformation ability.(2)T-shaped double corrugated steel plate concrete composite shear walls have good stiffness and bearing capacity.Axial compression ratio and shear span ratio are the key factors to determine the initial stiffness and ultimate horizontal bearing capacity of the specimen.The larger the axial compression ratio is,the greater the initial stiffness of the specimen with smaller shear span ratio is,but the degradation of stiffness and bearing capacity is more serious at the later stage of loading.In a certain range,increasing axial compression ratio can improve the ultimate horizontal bearing capacity of the specimen,but the deformation capacity becomes worse;when the shear span ratio decreases,the horizontal bearing capacity of the specimen increases greatly.(3)By observing the failure mode of the specimen in the whole process of loading,combined with the analysis of the distribution law of stress and strain,the stress mechanism of composite shear wall is revealed.The results show that the failure load of specimen under compression and bending failure depends on the bearing capacity of normal section,and the stress mechanism is similar to that of eccentric compression column.The results show that the height of the compression zone of the specimen under low cyclic loading is different from that of the flange under tension and compression,so the peak load is different and should be discussed separately.After theoretical derivation,a formula for calculating the bearing capacity of T-shaped double corrugated steel plate concrete composite shear wall is proposed.The results of the formula are in good agreement with the test results.(4)Based on the analysis of hysteretic curve and skeleton curve,a trilinear skeleton curve model is proposed by using the experimental fitting method,and the calculation formula of each key point and each stage stiffness on the skeleton curve is given.The regression analysis of the stiffness degradation data of the specimen is carried out,and the calculation formula of the stiffness degradation is summarized,and the restoring force model is established.The results show that the skeleton curve model and restoring force model are in good agreement with the experimental results.