不同类型土体盾构开挖面破坏形态分析

Numerical analysis of failure mechanism of shield excavation face in different types of soil

利用FLAC^(3D)分别对中砂与粉质黏土条件下盾构开挖面的破坏形态进行分析。研究结果表明:中砂开挖面的破坏形式主要为坍塌破坏,土体位移有明显的突变迹象且主要分布在隧道断面中上部;粉质黏土则表现为开挖面局部土体"隆出"的情形,土体位移出现逐渐增长且位移主要分布在隧道断面中下部。

Due to high quality of mechanization and informatization, shield tunnel became the main construction method of urban subway. How to adapted to the demand of excavation in different strata has been a key point in research. Analysis of failure mechanism of shield excavation face in medium sand and silty clay has been showed in this paper by FLAC30. The results indicate that ： collapse is the main failure form of excavation face in medium sand and displacement of soil has obvious signs of mutation and mainly distribution in the upper part of tunnel section. “ Uplift” is the main failure form of excavation face in silty clay and displacement of soil increase gradually and mainly distribution in the mid-under part of tunnel section.