盾构机近距离侧穿初支状态下暗挖隧道施工技术研究

Research on the Construction Technology of Shield Tunnelling Side-crossing Close to Mined-excavation Tunnel at the Initial Stage

以郑州某标段盾构机在进洞过程中近距离侧穿暗挖初支隧道为背景,研究暗挖区间与盾构区间近距离之间增设隔断桩+土体变位跟踪分析施工技术。结果表明:该技术妥善解决了地面旋喷加固困难的问题,避免了盾构机近距离平行侧穿暗挖初支隧道的风险,省略了地面开挖、进场设备旋喷加固、等待强度,施工协调、盾构停工等一系列繁琐工序,确保了盾构机安全、快速的通过暗挖初支隧道,缩短盾构施工工期近2个月。同时,该技术获得了业主及业内人士的高度评价,综合效益显著,也为类似地铁施工提供了借鉴和参考。

Relying on a certain constructing shield tunnelling machine of Zhengzhou metro side-crossing close to a mined- excavation tunnel at the initial stage, this paper studied the construction technology of adding partition pile plus tracking the soil displacement between the excavation interval and shield interval. The results showed that the technique could properly solve the problem of ground reinforcement by jet-grouted pile, avoid the risk of shield tunnelling parallel side-crossing close to a mined-excavation tunnel at the initial stage, and skip a serious of tedious procedures such as ground excavation, ap- proach equipment reinforcement by jet-grouted method, waiting strength, construction coordination and shield stoppage. It could ensure the shield machine quickly passing through the initial mined-excavation tunnel in a safety manner, shorten the shield construction period of nearly two months. Meanwhile, the technology was highly praised by the owners and the indus- try, and yielded significant comprehensive benefits, which could be served as a reference for similar subway construction.