盾构在高水头粉土粉砂及淤泥地层始发时易出现各种安全事故,工程上常采用地表注浆、地层冻结等方法预先对始发端地层进行加固处理。本文结合望江路盾构隧道地层特点,提出了一种三轴搅拌桩、高压旋喷桩及局部冻结相结合的联合加固方法,并系统介绍了该方法加固参数的确定和加固效果评价。经现场检测表明,各项条件均满足设计要求,盾构顺利始发,以期为类似工程提供借鉴。

There were various accidents likely to occur when shield tunnel launching in high water head and slit strata. Surface grouting, freezing and other methods were often used to pre-reinforce the initial strata in Shield Launching Hole. Combined with strata characteristics in tunnel of Wangjiang road, this paper put forward a combined reinforcement of triaxial mixing pile, high pressure jet grouting pile as well as local freezing. This paper introduced the determination principle of reinforcement parameters and effect evaluation. Field test showed that all the conditions meet the design requirements. Tunnel launched successfully and it can be a reference for similar projects.

U455.49