电力盾构隧道近距离侧穿既有桥梁数值模拟分析

Numerical Simulation Analysis of Electric Shield Tunnel Side-crossing Existing Bridge at Close Distance

以某电力盾构隧道工程为背景,采用现场监测和数值模拟相结合的方法,得到隧道近距离变曲线侧穿时桥面和桥梁桩基位移、应力等变化规律,分析隧道侧穿的影响。研究结果表明,隧道侧穿过程中桥面和桥梁桩基水平和竖向位移均逐渐增大,且隧道侧穿阶段引起的位移较大,后期位移逐渐趋于稳定;盾构隧道开挖掘进造成桥梁下部围岩地层损失,靠近隧道侧土体发生非对称偏转,导致桥面整体发生不均匀竖向位移并向靠近隧道侧偏移。当盾构隧道近距离侧穿时,应选取合理的盾构掘进参数,以减小对桥面和桥梁桩基的扰动。

Based on the background of a electric shield tunnel project,this paper adopts the method of field monitoring and numerical simulation to obtain the variation law of displacement and stress of bridge deck and bridge pile foundation when the tunnel is close distance variable curve side-crossing,and analyzes the influence of tunnel side-crossing.The research results show that the horizontal and vertical displacements of the bridge deck and bridge pile foundation gradually increase during the tunnel side-crossing process,and the displacement caused by the tunnel side-crossing stage is larger,and the later displacement gradually tends to be stable.The excavation of the shield tunnel causes the loss of the surrounding rock stratum at the lower part of the bridge,and the soil near the tunnel side undergoes asymmetric deflection,resulting in uneven vertical displacement of the bridge deck as a whole and shifting to the side near the tunnel.When the shield tunnel is close distance variable curve side-crossing,reasonable shield tunneling parameters should be selected to reduce the disturbance to the bridge deck and bridge pile foundation.