| Structural system of prefabricated shear wall does have a great number of joints,the connection performance of which directly determines the overall performance andseismic effect of the structure. Vertical joint, a part of assembly wall horizontalconnection, is usually configurated with a certain amount of horizontal connectingsteel bars so as to ensure the connection performance of joints. This thesis is thusintended to carry out a further study on the relationship between vertical joints andconnecting steel reinforcement ratio, and ensure the safety threshold value ofconnecting steel reinforcement ratio.Theoretical study on the cohesive performance of prefabricated shear wall jointsurface gives a detailed analysis of the factors influencing the cohesive performanceand the composition of cohesive force. The cohesive force of joint surface is made upof two parts: concrete cohesive force and reinforcement effect. Concrete cohesiveforce plays a major role before the joint surface cracks and slides. Once there is anoccurrence of slide between the walls on both sides, the cohesive force of concreteimmediately disappears. Reinforcement effect shoulders the main load after theinterface slides.This thesis is intended to give a clear explanation of the joint surface shearingperformance through designing the finite element model Z with the help of finiteelement software. Through using spring element to simulate the connectingrelationship between concrete and steel bars, and considering the factors influencingthe strength of concrete, the author analyzes the shearing performance of joint surfaceunder five different reinforcement ratios. With the infinite element analysis of jointsurface, this thesis comes up with load--shear displacement curves of differentreinforcement ratios under three degrees of concrete strength: C30, C40, C50, and theminimum reinforcement ratios under these three circumstances:0.238%，0.338%，0.382%.On the basis of joint surface finite element analysis and the results that have been achieved so far, this thesis sets up a finite element model of prefabricated shearwall, taking the influences of vertical joints into consideration. Finite elementanalysis studies the influence of joint connection reinforcement ratio towards theperformance of walls under different axial compression ratios. Through analyzing thefinite element result of prefabricated shear wall, the author finds out a threshold valuein the connection steel reinforcement ratio. When the reinforcement ratio ofconnection steel is smaller than that of threshold, the connection between wallscollapses; when the former is bigger than the latter, the degree of collapse is as sameas that of cast-in-place shear wall. Research finds that because certain collide happenswhen prefabricated shear wall joint is under pressure, its stiffness and bearingcapacity are smaller than those of cast-in-place shear wall. With the finite elementanalysis of prefabricated shear wall, the author finds out that when the shearingstrength of joint concrete is0.4N/mm2, the threshold reinforcement ratios ofprefabricated shear wall vertical joints, whose axial compression ratios are0.17,0.33,0.55, are0.33%,0.382%, and0.35%respectively. |
