Research on Leakage Treatment Technology for Deep and Large Foundation Excavation of Subway in Complex and Water Rich Strata
Qingdao is close to the coastline,and its groundwater is abundant;therefore,the deep and large foundation excavation of the subway is prone to groundwater leakage problems when it encounters complex strata such as soft and hard composite strata and tectonic fracture zones,etc.Based on the foundation excavation project of Zhoucun Station of Qingdao Metro Line 7,in accordance with engineering investigation,field testing,and field monitoring,the characteristics of water leakage in deep and large foundation excavation through unfavorable geological sections are studied,and the system grouting process of external grouting+in-excavation grouting under a CSM waterproof curtain is proposed.The results show that the structural fracture zone is a good channel for groundwater,and the side wall of the foundation excavation is prone to water leakage.The grouting process of segmented grouting and the combination of surface and in-excavation grouting can effectively deal with the problem of large-scale leakage of groundwater and make up for the shortcomings of the CSM waterproof curtain.The maximum grouting amount of the surface in the whole process of grouting is 410.5m3,and the maximum horizontal displacement of the pile is 26.4mm,which occurs at the position where the fault fracture zone is connected with the foundation pit retaining pile.When the foundation excavation is re-excavated,there is no seepage point on the side wall of the foundation excavation.The actual grouting water stop effect is good.
subway stationsdeep foundation excavationcomplex geologywaterproof curtaingroutingleakageconstruction
万方数据
维普
