不良地质条件下盾构机整体下沉处理技术——基于冻结帷幕加固技术

Treatment Technology of Frozen Curtain-based Reinforcement on Integral Subsidence of Shield Machine under Unfavorable Geological Conditions

针对现有城市轨道地下工程中盾构施工方法在不良地质条件下易发生盾构机整体下沉等工程事故,提出了适用于流塑状淤泥地层、富水含砂地层的积极冻结技术。通过对某地铁工程盾构机整体下沉事故的成功处理,验证了冻结帷幕加固技术的有效性。工程事故处理结果表明,采用冻结加固处理技术将盾体、盾体周边土体及接收端的地连墙冷冻胶结成一体,可以提高盾体周围地层的承载力,有效地防止水土流失与盾构机整体下沉。

In view of the shield technology in the existing urban rail underground engineering, under the adverse geological conditions, the overall sinking of the shield machine is easy to occur, and the active freezing technology suitable for the flow-plastic silt stratum and the water-rich sand-bearing stratum is proposed.Through the successful treatment of the overall sinking accident of a subway engineering shield machine, the effectiveness of the frozen curtain reinforcement technology was verified.The results of engineering accident treatment show that the frozen and reinforced treatment technology is used to freeze and cement the shield body, the surrounding soil of the shield body and the grounding wall of the receiving end, which can improve the bearing capacity of the surrounding layer of the shield,and effectively prevent soil erosion and the shield machine sink as a whole.