大流速强透水砂卵石地层地铁联络通道冻结法设计及施工问题处治技术研究

Study on Technical Solutions to the Problems in Freezing Method Design and Construction of Subway Cross Passages in Sandy Cobble Stratum with High Flow Rate and High Permeability

南水北调工程的实施,使北京地区地下水得到大量的补给,地下水水位急剧上升,给轨道交通建设带来一定难度。通过地铁12号线某区间隧道联络通道冻结法设计和施工的工程实践,提出大流速、强透水砂卵石地层冻结施工保障措施,同时对冻结过程冻结壁不交圈原因进行分析与处理,确定出冻结壁薄弱位置并提出相应工程对策,进而分析大流速、强透水砂卵石地层冻结技术可行性,为类似冻结工程设计施工提供参考。

Attributed to construction of the South-to-North Water Diversion Project,the groundwater supply in Beijing area has been replenished amply and consequently the groundwater level has risen sharply,which makes rail transit system construction more difficult.After practical design and construction of the cross passages using freezing method in a running tunnel section of the Metro Line 12,the supporting measures for freezing method construction in sandy cobble stratum with high flow rate and high permeability have been proposed.Besides,the cause of freezing wall failing to be closured has been analyzed,the weak parts of freezing wall have been identified and thus the engineering solutions have been proposed.Then the technical feasibility of the freezing method used in sandy cobble stratum with high flow rate and high permeability is analyzed.The results will be used for reference in engineering design and construction of the similar projects that use the freezing method.