Numerical Simulation Of Interfaces In Concrete Dams And Its Application

Joints such as transverse and longitudinal joints, and cracks caused by all kinds of factors are quite common in concrete dams. All these joints and cracks may open, or slide or keep sticking under different loading conditions. When analyzing structures with joints or cracks, state changing of these interfaces will affect stress and displacement of contact surface. It's important to simulate occuring, propagating and state changing of cracks by numerical method and analyze their effects on stress and deformation so as to gain the real behavior of a concrete dam.The studies are financed with the project of Safety Analysis of Chencun Arch Dam. Iterative algorithm is studied in this dissertation to simulate the state changing. Keys, grouting, water pressure on contact faces, and filling material etc. are also considered in the interface model so that it can be used to simulate most of interfaces in concrete dam and study their impacts on behavior of dam. Studies on hydraulic fracture of high concrete gravity dam were carried out with the interface model developed.The main achivements in this dissertation are as follows:1. On model development and computing method studying: â‘ Open-close iterative algorithm of interface was studied, based on which zero-thickness interface model was built to simulate state changing of contact faces, and the referential value range of normal and tangential stiffness coefficient of the model was given in the dissertation. â‘¡The influence of fissure filling was considered in the interface model to simulate the opening increase of cracks. â‘¢The constitutive relation of keys with shape of trapezia, triangle and sphere was deduced and added to the interface model. Conditions against sliding of contact faces were presented and numerical methods to simulate opposite sliding of the contact faces were discussed primarily. â‘£ Mass calculations of key by fine FE model were carried out through which the shearing stiffness coefficient of trapezia key was suggested.2. On computing program compiling: Program was compiled and five instances were built to test the correctness and astringency of the interface model, in which open-close state change, effects of fissure filling and key model were tested to be...