基于流固耦合的双线盾构隧道施工诱发地表沉降分析

Surface settlement induced by double-line shield tunnel construction based on fluid-solid coupling theory

富水地区盾构掘进时,受地下水渗流影响,土体骨架中孔隙水消散产生土体固结,引起地表沉降明显增加。分析渗流条件下盾构隧道施工诱发的地表沉降对控制施工安全具有重要意义。在流固耦合影响下,本文基于厦门市轨道交通2号线东孚站—马銮北站区间某区间段双线盾构隧道工程,研究了隧道盾构施工过程所引发的地表动态沉降问题。通过建立有限差分三维数值计算模型,分析了隧道施工过程中地表沉降、管片变形和隧道洞周孔隙水压变化的规律。计算结果与工程实测数据规律吻合较好,可为类似工程施工提供指导。

In the construction of shield tunnels in coastal and groundwater-rich areas,groundwater seepage leads to the dissipation of pore water in the soil skeleton,resulting in soil consolidation,which will cause a significant increase in surface subsidence.It is of great value to accurately analyze the surface subsidence induced by shield tunnel construction under the condition of seepage.Based on the double-line shield tunnel project of Dongfu Station to Maluan North Station of Xiamen Rail Transit Line 2,the surface subsidence caused by shield tunnel construction under fluid-solid coupling is studied in this paper.Through the finite difference three-dimensional numerical calculation model,the basic laws of surface settlement,segment deformation,and pore water pressure around the tunnel during tunnel construction are analyzed.The calculated results are in good agreement with the measured data.