上软下硬地层盾构施工技术研究

Study of Shield Construction Technology in Soft Upper Stratum and Hard Under Stratum

依托深圳地铁2号线东延线土建2222标侨香站—香蜜站盾构区间,分析了在上软下硬地层中盾构法施工存在进度缓慢、刀具磨损严重、喷涌等难点和风险。为提高上软下硬地层盾构施工的掘进效率,文章给出了具体的盾构掘进参数;针对上软下硬地层盾构施工易发生结泥饼和喷涌等问题,从其发生机理出发,研究了相应碴土改良技术;针对上软下硬地层周边环境复杂、开舱作业风险高的问题,研究了带压开舱换刀技术。

Based on the construction of the shield tunnel from the Qiaoxiang Station to the Xiangmi Station of Lot 2222 of the Shenzhen Metro line 2,this paper analyzes the difficulties and risks of slow progress,serious cutter wearing,and blow-out in the soft upper stratum and hard under stratum.Concrete parameters of shield driving are given.In light of the mechanism of mud cake and blow-out occurring,the techniques of soil improvement were studied.Furthermore this paper addresses cutter change techniques in a pressurized chamber.