Research On The Long-term Performance And Sectional Optimization Of Rubber Gasket Of Utility Tunnel’s Lining Joint

In recent years,with the rapid development of economy and culture,China’s urbanization has made great progress.At the same time,the improvement of urbanization rate also brings about relevant problems that cannot be ignored,such as dense population,traffic pressure and increasingly insufficient ground space.The concept of underground utility tunnel provides a new direction to solve the above problems.The underground utility tunnel has become a symbol of the modernization of municipal construction management in developed cities at home and abroad as well as an important part of modern urban public management.Compared with the cast in place utility tunnel,prefabricated technology has the unique advantages of high efficiency,high precision and low impact,which gradually becomes the main direction of the development of utility tunnel.Based on a comprehensive pipe gallery project in Guangzhou,on the one hand,this paper carries out the research of the basic and long-term performance test of the EPDM gasket at the joint.On the other hand,relies on the existing theories,the finite element model of gasket was established to explore the optimization direction of the gasket section form,the grooves of the segments and the amount of dislocation.The main works are as follow:(1)In order to establish the finite element model and gain the load-displacement curve as well as the assembly force and the contact stress,the basic performance tests of EPDM materials were carried out,including uniaxial tensile and uniaxial compression tests.(2)Carrying out the long-term performance tests of EPDM materials,using the experimental data to fit the decreasing function and ageing coefficient,and then verify whether this section form of the rubber gasket can meet the waterproofing requirement of 100 years.(3)Through establishing the two-dimensional finite element model of rubber gasket,this paper will explore the influence of the section form and the grooves of the segments on the contact stress,and then defines some design recommendations and optimization direction.On the other hand,aimed to provides some reference for the monitoring and early warning during the gasket assembly process and operation stage,this paper simulate the compression process of segment joints with different amount of dislocation,and the influence of the amount of staggered joints on the contact stress of gasket will be explored.