小曲线半径叠落盾构隧道侧穿桥桩响应分析

Analysis of displacement response of side-crossing bridge pile of overlapping shield tunnel with small curve radius

为明确小曲线半径叠落盾构隧道侧穿桥桩时其对邻近桥桩所造成的影响,文章以哈尔滨地铁3号线公路大桥站—河松街站区间小曲线半径叠落盾构隧道工程为依托,建立FLAC 3D数值模型,考虑同步注浆层厚度和浆液时效性因素,对叠落盾构隧道穿越过程中邻近桥桩的位移响应情况展开分析。结果表明:工况二、三下邻近桩基的竖向位移已满足安全要求,但个别承台水平位移始终大于安全要求,在实际施工中应对承台水平位移进行严格监测;在实际施工中应尽可能控制较小的盾尾空隙和使用快硬早强的同步注浆浆液,可有效减小邻近桩基位移响应。

In order to clarify the influence of the small curve radius overlapping shield tunnel on the adjacent bridge piles when it crosses the bridge piles.In this paper,based on the overlapping shield tunnel project with small curve radius between Highway Bridge Station and Hesong Street Station of Harbin Metro Line 3,FLAC 3D numerical model is established.Considering the thickness of synchronous grouting layer and the timeliness of slurry,the displacement response of adjacent bridge piles during the crossing process of overlapping shield tunnels are analyzed.The results show that the vertical displacement of the adjacent pile foundation under the second and third working conditions has met the safety requirements,but the horizontal displacement of some pile caps is always greater than the safety requirements,and the horizontal displacement of pile caps should be strictly monitored in actual construction.In the actual construction,the smaller shield tail gap should be controlled as much as possible and the synchronous grouting slurry with fast hardening and early strength should be used,which can effectively reduce the displacement response of the adjacent pile foundation.