超浅埋大盾构近距离下穿市政隧道控制技术

The control technology of ultra-shallow buried large-diameter shield under-pass existing municipal tunnel at close distance

摘要

以广州地铁十二号线云溪公园站—小金钟站区间左线大盾构下穿金园路隧道为例，研究了在上软下硬复杂地层条件下大盾构近距离下穿对既有市政隧道沉降变形的影响。通过采取不同阶段的保护对策及技术方案，对大盾构下穿金园路隧道设计和施工进行了指导。综合运用理论分析，通过对金园路隧道保护设计方案的比选论证，最终确定采用在变形缝位置设置混凝土箱涵的方案。在大盾构下穿金园路隧道的施工过程中，采取了掘进控制、径向孔注浆、管片壁后深孔注浆及加密监测频率等措施，有效解决了沉降变形控制技术难题，为类似工程提供了借鉴参考。

Abstract

Taking the left line of the section from Yunxi Park Station to Xiaojinzhong Station on Guangzhou Metro Line 12 as an example, the impact of large-diameter shield under-passing on the settlement and deformation of the existing municipal tunnel under complex geological conditions of upper soft and lower hard layers was investigated. By adopting protection measures and technical solutions at different stages, guidance was provided for the design and construction of the large-diameter shield under-passing. Based on the theoretical analysis, through the comparison and demonstration of the protection design scheme of Jinyuan Road Tunnel, the scheme of setting concrete box culvert at the deformation joint is finally determined. Based on the theoretical analysis, through the comparison and demonstration of the protection design scheme of Jinyuan Road Tunnel, the project adopted the scheme of setting concrete box culverts at the deformation joint. During the process of under-passing, measures such as excavation control, radial hole grouting, deep borehole grouting behind the segment, and increased monitoring frequency were taken, effectively solving the technical difficulties of settlement deformation control and providing reference for similar projects.

关键词

大盾构 / 近距离 / 下穿 / 上软下硬 / 沉降变形

Key words

large-diameter shield / close distance / underpass / upper soft and lower hard layers / settlement deformation

Author summay

温晓虎(1982—), 男, 高级工程师, 硕士, 主要从事地铁建设工作。E-mail: [e-mail]