盾构隧道局部渗漏水对其力学特性的影响

The Influence of Partial Water Leakage on the Mechanical Properties of Shield Tunnels

针对盾构隧道接头渗漏水导致结构长期运营安全性能降低这一问题,文章建立了接头渗漏水数值计算模型,对接头局部渗漏水条件下管片结构的力学响应进行分析。结果表明:接头渗漏水会导致接头附近管片所承担的外水压力明显减小,且减小量值随着渗流量的增加而增加;管片结构内力随着渗流时间的增加,体现为快速增加、缓慢增加和趋于稳定的三阶段变化特征;结构弯矩与轴力的量值与接头渗漏量呈现正相关性;当接头总的渗漏量相同时,外侧受拉区接头处渗漏水对结构内力的影响大于内侧受拉区接头处渗漏,且单一接头漏水时,接头处的水压力减小量值大于多接头渗漏工况;对于多接头渗漏而言,渗水条件下结构渗漏侧的弯矩值大于未渗漏侧的弯矩值,表现出明显的非对称分布特征。

To address the problem of long-term operational safety degradation caused by water leakage in the joints of shield tunnels,this paper develops a numerical calculation model for joint leakage and analyzes the me⁃chanical response of the segment structure with water leakage in the joints.The results show that water leakage in the joints could lead to a significant reduction in the external water pressure borne by the segments in the vicinity of the joints,and the reduction increases with the increase in the amount of leakage;the variation of internal force of the segment structure would experience three stages of rapid increase,slow increase and stabilization along with con⁃tinuous leakage;a positive correlation exists between the magnitude of structural bending moments and axial forces and the amount of joint leakage;when the total leakage volume in the joints is the same,the leakage at the joints in the external tension zone has greater effect on the internal forces of the structure compared with that of leakage at the joints in the inner tension zone,and the reduction value of water pressure at the joints,when a single joint is leaking,is greater than that of multi-joint leakage;for multi-joint leakage condition,the bending moments on the leaking side of the structure under leakage condition are greater than those on the non-leaking side,showing an ob⁃vious asymmetric distribution.