Study on the replacement technology of shield tail brush by grouting for water plugging in weak and locally permeable stratum
In the construction of urban rail transit,due to the increasing number of long-distance and small-radius shield tunneling,the shield tail brush is worn because of in the long-time or uneven stressed state,which reduces or loses its sealing property,so it needs to be replaced in time.This study took the shield tail brush replacement project of the en-trance and exit line interval between Hudian Road Station and Huqiu Wetland Park Station of Suzhou Rail Transit Line Eight,as engineering background to analyze and compared the characteristics and applicable conditions of different water plugging methods based on various water plugging methods that can be used in the replacement of the shield tail brush.We combines with the fact that the project was located in the weak and locally permeable stratum to put forward and implement a replacement method of shield tail brush by multi-method grouting for water plugging.This method effectively seals off groundwater before and behind the shield tail by injecting polyurethane slurry,inert slurry and ce-ment-waterglass double slurry into the soil behind the shield tail,as well as by radially injecting inert slurry through the shield body into weak and locally permeable stratums.Then the first shield tail brush was replaced by tearing down the last ring of pipe segment to expose the first shield tail brush.At the same time,during the replacement of the shield tail rear pipe segment longitudinal tie,the jack support and other ways maintained stability.This replacement method provided a complete set of process and method for replacing the shield tail brush by grouting for water plug-ging in weak and locally permeable stratum.During the replacement of the shield tail brush,the measured surface data showed that the cumulative settlement of the surface and the daily settlement meet the control requirements.After the grouting reinforcement,the observation holes on the pipe segment were opened,and it was found that the effect of water plugging effect was satisfactory.It only took 14 d to resume tunneling,and better implementation results had been achieved,which could provide reference for similar projects in the future.
shield tunnelweak and locally permeable stratumshield tail brush replacementa variety of slurry cross groutinggrouting for water plugging
万方数据
维普
