岩土体开挖变形的分步模拟方法及其工程应用

本文提出了一种岩土体开挖变形的分步模拟方法;该方法以岩土体弹塑性参数和现场变形监测数据为基础,以开挖、施加支护等工程措施的实施为时间节点,以弹塑性荷载分步释放来表征岩土体荷载逐步释放的过程,模拟了岩土体开挖和支护前、后的变形效果,并近似地模拟出锚固、衬砌等措施的应力、变形状态,将岩土体复杂的粘弾塑性问题转化为了较简单的弹塑性问题。运用该方法模拟了涔天河水利枢纽右岸进口段密集洞室群的施工开挖和支护全过程,获取了施工过程中围岩的应力、变形及稳定特征,同时结合数值模拟的成果给出了相应的工程施工建议,可为工程的快速化施工提供参考。

Method of step by step simulation on rock and soil mass deformation during excavation and its application

A method of step by step simulation on the rock and earth deformation during excavation is proposed herein； by which the deformation effects before and after excavation and supporting of earth and rock mass are simulated by taking the implementation of engineering measures for excavation，supporting，etc.as the time nodes and characterizing the load gradually releasing process of earth and rock mass with the gradual release of the elastoplastic load in accordance with the elastoplastic parameters and the monitoring data of the in situ deformation of earth and rock mass，thus the complicated visco-elastoplastic problem is converted into a more simpler elastoplastic problem. This method is applied to simulate the whole process of the excavation and supporting of the tunnel-chamber group at the intake section on the right bank of Centianhe River Water Control Project，and then the stress，deformation and stability characteristics of the surrounding rock during the construction are obtained，meanwhile，the relevant suggestions for the construction are given out in combination with the achievements from the numerical simulation concerned，which can provide a reference for the rapid construction of the project.