大型围堰平面应变问题的一种算法

An Algorithm for the Plane Strain Problem of Huge Cofferdams

对大型围堰施工过程采用逐级施加载荷进行模拟，支配方程在空间上采用有限元法离散，配合载荷的逐级施加用静态近似求解．对土体的应力应变关系，采用邓肯—张的非线性弹性模型，用于其增量型应力应变关系的切线模量及泊松比．考虑混凝土防渗墙与土体的相互作用，在接触面上采用了古德曼单元．计算了堰体与防渗墙的位移及应力。

For simulating construction procedure of huge cofferdam, the load is added stage by stage. The solving process involves the finite element programming in space and the time stepping scheme with static approximation associated with the stage load. The stiffness matrix in each increment analysis is not changed. The stress strain increment dependence adopts a nonlinear model, the modulus and Poisson’s ratio given by Duncan Zhang are expressed. Considering the interaction between concret water tight core wall and soil, a Goodman contact element B given on the contact surface between wall and soil. The displacement and stress of the body of cofferdam and the water tight core wall are given. The results consist with pratice qualitatively.