大直径土压平衡盾构掘进引起的地表沉降分析

Numerical Simulation Analysis of Ground Surface Settlement Caused by Large Diameter EPB Shield Tunneling

为研究大直径土压平衡盾构掘进对地表沉降的影响,以迎宾三路隧道新建工程为背景,基于ANSYS与FLAC3D软件,建立了大直径土压平衡盾构穿越地层的三维模型。数值模拟结果表明,大直径土压平衡盾构施工会引起较明显的地表位移;数值模拟结果与经验公式及实测数据相吻合,证明了该数值模拟结果的可靠性以及等代层在本模型中的适用性;土仓压力取值过大或者过小会破坏土体极限平衡,造成过大的地表位移;当土仓压力在适当的范围内取值时,其大小变化对地表沉降基本无影响。

To study the influence of large diameter EPB shield tunneling through shallow covering area on the ground surface settlement, three -dimensional model is established based on ANSYS and FLAC3D in the background of new tunnel construction project of Yingbinsan Road, Shanghai. It is revealed that the large diameter EPB shield driving can cause obvious displacement of ground surface. Numerical results are similar with those by empirical for- mula and measured data, which identifies their reliability and the applicability of equivalent layer. Too large or small soil pressure of the chamber will destroy the limit equilibrium of soil and lead to excessive displacement of the ground surface, but changes of the chamber soil pressure in appropriate range will not affect the settlement results.