地震作用下土质库岸边坡失稳运动及初始涌浪数值模拟方法

Numerical simulation of landsliding and initial surges for soil banks of reservoir under earthquake action

视库岸失稳、坡体滑动、首浪产生为完整连续的过程,建立地震作用下土质库岸边坡失稳运动及初始涌浪数值模拟方法。首先以动力时程强度折减法进行土质库岸边坡动力稳定分析,根据塑性区贯通确定可能的库岸失稳滑动范围。然后对滑坡体、库水和空气等三相介质采用统一的控制方程N-S方程及适当的本构关系来描述其运动,采用双重LEVEL SET函数追踪不同介质的分界面,反映滑坡体、库水和空气三者间强烈的耦合作用,实现地震作用下土质库岸边坡滑动过程及入水产生涌浪的数值模拟,在有限元框架内开发相应的三维计算程序进行数值分析。通过数值算例验证本文方法及计算程序的有效性。

A numerical method for simulation of landsliding and initial surges for soil reservoir banks under earthquake action was developed taking into account the full process of instability development,sliding and initial surge formation.A dynamic stability analysis of soil reservoir landslides was made with a time-dependent strength reduction method,and the scope of possible instable region was evaluated using plastic strain distribution.Then the N-S equations and a proper relationship were used to describe the fluid motions of landslides,water and air.A double level-set method was adopted to track the interface of different fluids in the simulation,and coupling of the three fluids in the full process of landsliding and surge formation was simulated.This method was implemented in the frame of a FEM code,and it was verified by a numerical example.