Study On The Force Performance About Joint Of Prefabricated Integrated Pipe Gallery Connected By PC Steel Bar

The underground comprehensive pipe gallery of the city is the direction for the development of municipal infrastructure construction,and it is also the need to promote the economic development of the city.From the aspects of construction period,economy,and quality,precast comprehensive pipe gallery have greater advantages over cast-in-place comprehensive pipe gallery.The importance of joints in the deformation and stress of precast comprehensive pipe gallery is undoubted.In terms of the study on the performance of precast comprehensive pipe gallery,there is a lack of available reference data.Based on the existing related theories and experiments,this paper relies on the comprehensive pipe gallery project of the wisdom city of Tianhe City in Guangzhou.And carrying out the research from the pressure performance and cross-section design of the joint rubber gasket and the force performance of the transverse joint and the longitudinal joint.The research was conducted in various aspects,mainly focused on in the following aspects:(1)A rubber gasket compression test was conducted to determine the maximum pressure at which the vertical compression displacement of the rubber gasket reached 50% compression,and get the load-displacement curve and the assembly force the rubber gasket required.(2)Establishing a finite element model of the rubber gasket compression plane,using the experimental data to select the appropriate constitutive model and parameters,simulating the compression process of the rubber gasket,and then studying the effect of different slotting and opening forms on the compressive performance of the rubber gasket to guiding the section design.The results of the study showed that the increase of the slotted area and the opening area can reduce the assembly force of the rubber gasket.The number and shape of the slots and the number and arrangement of the openings have a certain influence on the assembly force.(3)Establish a three-dimensional finite element model of a precast comprehensive pipe gallery's transverse joint,find a reasonable loading method,and study the shear and bending properties at the joint of the pipe gallery: including deformation characteristics,stress distribution,shear stiffness and bending stiffness.Then the influences of factors such as horizontal axial force,distance between steel rods,concrete thickness,mortise length,mortise width and mortise angle were studied to provide reference for the design of transverse joints.The results of the study show that increasing horizontal axial force,reducing the spacing between steel bars and increasing the thickness of concrete can increase the shear and bending stiffness of transverse joints.(4)Based on the study of transverse joints,establish a three-dimensional finite element model of precast comprehensive pipe gallery's longitudinal joints to study the shear and bending properties at the joints of the pipe gallery: including deformation characteristics,stress distribution,shear stiffness,bending stiffness.Then the factors such as the horizontal axial force,the presence or absence of transverse joints and the number of subdivisions were studied to provide reference for the design of longitudinal joints.The results of the study indicate that increasing horizontal axial force and the number of cabins in the comprehensive pipe gallery can improve the shear and bending stiffness of the longitudinal joints;When there are no transverse joints,the shear and bending stiffness of the longitudinal joints is slightly greater than that of the transverse joints.