考虑尾隙的盾构隧道土压力离散元数值分析  

Numerical Simulation on Earth Pressure for Shield Tunnels Incorporating Tail Gaps by DEM

作　　者：蒋明镜[1,2] 王富周[1,2] 朱合华[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《地下空间与工程学报》2010年第1期28-32,共5页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(50679057);国家自然科学基金(10972158);国家863计划(2006AA11Z102)

摘　　要：采用改进的离散元商业软件PFC2D对砂土层中管片周围的土压力进行了大量的数值模拟,重点研究了埋深、尾隙等因素对管片周围土压力分布的影响。研究结果表明:尾隙存在时,隧道顶部的土体产生了不均匀沉降,导致压力拱效应的产生;隧道顶部至地表出现转动加剧区域;应力路径变化过程表明,隧道周围土体经历了先卸载后加载的变化过程;在应变路径变化曲线上可将管片周围土体的变形划分为三个变化阶段。Lots of numerical investigation were carried out on the earth pressure around the tunnel segments in granular materials by PFC2D. The key research work is about the distribution of earth pressure considering the factors of buried depth and ground loss. It was indicated that the soil arching took place owing to the non - uniform displacement of the soil above the tunnels when the tail gap exists. A significantly rotating region was formed from the head of the tunnel to ground surface. During the tunneling, an unloading -loading process was observed from the variation of stress paths. The strain of the soil around the tunnel can be divided into three phases on the strain paths curve.

关 键 词：盾构隧道 离散元 土压力 尾隙 

分 类 号：U451[建筑科学—桥梁与隧道工程]