沉管隧道接头非线性力学性能模拟方法

摘要

A criterion for seismic safety for immersed tunnels is important for their design.The nonlinear analyses of the materials and the contact are important for simulation of the nonlinear behaviors of joints using the finite element method.To simplify the calculation,an adjustment factor is introduced to modify the judgment condition in the contact algorithm,with consideration of the nonlinear contact between boundaries.The nonlinear behaviors of Gina gasket are also taken into account.By modeling,the axial stiffness,the flexural stiffness and the coupled shear stiffness of the immersion joint are obtained.A quasi-static analysis based on the numerical simulation is presented,in which different water pressures are considered due to the significant variations of the water depth,and the stiffness of the immersion joint under multi-level loads is also studied.%沉管隧道柔性接头的力学性能是其抗震设计的关键准则.用有限元方法模拟接头的非线性力学性能需要解决接头处材料非线性和接触非线性两个问题.为简化分析计算,该文采用分段线性化的方法表征接头的材料非线性问题,引进调整因子改进接触算法中的判断条件,处理接头的边界非线性问题.通过沉管隧道接头的三维精细化建模,研究了沉管隧道接头在拟静力载荷下的响应,获得了接头的轴向等效刚度曲线、抗弯刚度曲线和非线性耦合的剪切特性曲线,进而分析了不同轴向压力对接头剪切特性的影响.