地铁工程盾构接收渗漏险情的处理实践

Practice of Emergency Treatment for Sudden Leakage of Metro Shield Receiving

为研究地铁盾构接收洞门渗漏处理的措施,保护周边复杂环境安全,以某盾构接收端突发⑦1-2砂质粉土层中的承压水穿透⑥粉质黏土层从洞门涌出的险情处置为例,通过对渗漏成因的分析、各处置方案进行比选,提出盾构停止掘进、盾壳内壁冻结封堵渗漏通道的处理方案,达到封水条件后抽干接收井内的积水,将盾壳留置在地层中并施工隧道衬砌,最终完成盾构接收。研究结果表明:地面引孔注聚氨酯的措施对洞门渗漏承压水层突涌的封堵效果不佳,通过冷板冻结可有效冻结漏水通道,但须考虑水体流动带来的冷量损失。

The sudden confined water inrush emergency of⑦1-2 sandy silt layer pressure water that penetrates through the(6)silty clay layer and gushes out of the tunnel portal is studied to find out the leakage treatment measures and protect the safety of surrounding complex environment.Based on the analysis of the causes of the leakage and the comparison of various treatment schemes,the scheme of freezing on the inner wall of the shield shell and sealing the leakage path without shield driving is proposed.When the water leakage channel is blocked,the water in shield receiving shaft is drained,the shield is retained in the soil layer and cast-in-place reinforced concrete tunnel lining is constructed,and finally the shield is received.The study results show that the polyurethane injection is not effective in blocking the water inrush of the leakage of confined water layer at the tunnel portal,while the leakage channel could be effectively frozen by the cold plate freezing,but the cooling loss caused by the water flow should be considered.