The cross passage of Zhangcun Station of Qingdao Metro Line 4 is located in shallow water-rich sand layer.In order to solve the problem of water and sand gushing in the excavation process,a multi-method composite grouting reinforcement technology is adopted.The mold bag pile is arranged on the outer contour of the key reinforcement area.The mold bag pile method can play a role in pile reinforcement,at the same time,it can control grouting diffusion and inhibit surface uplift.The segmented steel pipe piles are arranged in the key reinforcement area,and the segmented injection method is adopted.The uniform diffusion is beneficial to the reinforcement effect and can avoid the lifting problem caused by local uneven grouting.In the medium-coarse sand stratum,the infiltration effect of cement grout can not be ignored.The grouting diffusion radius is considered as 1.2m,which is proved to be reasonable in practice.After the grouting of shallow buried water-rich sand layer,combined with vacuum dewatering,the water-free construction environment in the tunnel is realized.The three methods of steel pipe pile,mold bag pile and grouting constitute a composite reinforcement technology.Combined with other auxiliary process methods,it effectively solves the problem of shallow buried water-rich sand layer treatment,which has reference significance for similar projects.
Mold bag pilSteel pipe pilesMulti-method composite grouting reinforcementInfiltration effect
万方数据
维普
