Study On Linear Contact Normal Stiffness Of Shield Segment Joint

The ability of segment joint to fight the role of the external force is measured by the rotational stiffness of segment joint.But in the actual engineering the rotational stiffness of segment joint is only rely on experience or field test values,and there is no good way to determine.Therefore,to find a simple and reasonable method to determine the value of rotational stiffness of segment joint is particularly important.This article takes the stiffness to measure the stress characteristics of joints and the theoretical analysis of mechanical properties for segment joints.This method calculated the the analytic solution of the stiffness.The finite element analysis method and test are used to produce the reason and the measuring method of stiffness.The main works and research achievements include:(1)The joint model with no bolt is used to make mechanical analysis of segment joint, the relation between the bending moment, angle and the normal stiffness was obtained,and the effects of the bolt on the mechanical behavior of joint based on the existing test is studied.The results showed that the bolt has little effect on the mechanical behavior of bolted joint segment before reaching the ultimate bending moment.(2)The finite element simulation analysis was carried out on the direct head test,and the spring is used to simulate the normal stiffness values of the joint. The theoretical analysis is compared with experimental values, and to provide basis for reasonable the mechanical properties of the stiffness of segment joint.The damage resistance can be improved by the increase of normal stiffness,and The normal stiffness can be improved by the increase of axial force.(3)Firstly, contact surface roughness of joint for the influence of the stiffness are analyzed.Secondly,self loading instrument is used to test the stiffness values of the different contact surface flaw. Thirdly,roughness tester is used to test the corresponding concrete roughness, and the value of roughness is used to measure the normal stiffness of the joint.This paper presents a simple method to measure the capacity of joints to resist deformation.