团九二期输水隧洞近距离下穿桥梁桩基技术方案研究

Research on the technical scheme of pile foundation of bridge under Tuanjiu Phase II tunnel by shield tunneling

摘要

随着市政基础设施建设快速发展，新建隧洞与既有工程之间的交叉穿越愈发常见。盾构法近距离下穿桥梁桩基不可避免对周围地层产生一定扰动，导致线路不平稳，威胁其正常运行。为探究盾构法对桥梁桩基的影响，并提出具备参考意义的解决措施。以团九二期输水隧洞近距离下穿北京五环路红山口桥工程为背景，在评估得出红山口桥应满足的变形控制技术指标后，提出隧洞侧穿桥桩设计方案，并通过Midas/GTS有限元分析软件进行全过程施工模拟确定桥梁结构是否满足技术指标。结果表明：采取克泥效注浆、洞内深孔注浆、增强二衬分缝止水能力的设计方案对在建隧道进行加固，可减小施工对红山口桥桩基稳定性的影响；将Midas/GTS模拟得到的施工过程红山口桥变形值与控制技术指标对比，结果显示团九二期输水隧洞正常施工条件下，不会影响红山口桥的结构安全。研究成果可为同类型工程施工设计提供参考。

Abstract

With the rapid development of municipal infrastructure construction, crossing between new tunnels and existing projects is becoming more common. The shield tunneling method will inevitably cause some disturbance to the surrounding strata, which leads to the instability of the line and threatens its normal operation. In order to explore the influence of shield method on bridge pile foundation, and put forward some solutions with reference significance. Based on the Hongshankou Bridge project of the second phase of Tuan Ninth-phase water transmission tunnel under the Beijing Fifth Ring Road in a short distance, after evaluating the deformation control technical indicators that Hongshankou bridge should meet, the design scheme of lateral tunnel bridge piles is proposed, and the three-dimensional whole process construction simulation is carried out by Midas/GTS to determine whether the bridge structure meets the technical indicators. The result show that the influence of construction on the stability of Hongshankou bridge pile foundation can be reduced by adopting the design scheme of grouting with mud effect, deep hole grouting in the tunnel and strengthening the water sealing capacity of the second lining. By comparing the deformation value of Hongshankou Bridge in the construction process with the control technical index obtained by Midas/GTS simulation, the result show that the structural safety of Hongshankou bridge will not be affected under normal construction conditions of TuanninII water transmission tunnel. The research result can provide reference for the construction design of similar projects.

关键词

团九二期 / 盾构 / 下穿桥梁桩基 / Midas/GTS有限元

Key words

Tuanjiu Phase Ⅱ / shield machine / underpass bridge pile foundation / Midas/GTS finite element

Author summay

李 悦(1997—), 女, 工程师, 硕士, 主要从事水工结构设计。E-mail: [e-mail]