Research on joint deformation characteristics of prefabricated diaphragm walls
In order to study the influence of joints on the deformation characteristics of prefabricated diaphragm wall and take reasonable improvement measures,the cast-in-place wall was replaced by prefabricated diaphragm wall by field test method,and the measured deformation data were compared and analyzed.Based on the analysis of measured data,PLAXIS2 D finite element software was used to simulate and analyze the influence of transverse joints at different depths on the deformation characteristics of prefabricated diaphragm walls.PLAXIS3 D finite element software was used to compare the horizontal and vertical deformation patterns of cast-in-place wall and prefabricated diaphragm wall,and the influence of vertical joints on the deformation characteristics of prefabricated diaphragm wall was analyzed.Finally,aiming at the problem of large deformation shown by the measured data,four improvement measures were proposed to change the stiffness of crown beam,the stiffness of enclosing purlin,the width of wall,and the support position,which were verified by the finite element software PLAXIS3 D.The results show that the joints of prefabricated diaphragm walls weaken the stiffness of wall and increase the deformation degree.When the transverse joint above the bottom of the pit fails,the horizontal displacement of the wall will increase significantly,while when the transverse joint below the bottom of the pit fails,the horizontal displacement of the wall will not increase significantly.The vertical joint will significantly reduce the overall stiffness of the prefabricated diaphragm walls,making its collaborative deformation capacity worse and deformation more difficult to control.Properly adjusting the support position can effectively alleviate the dislocation between the wall and reduce the deformation of the wall.