Abstract:

Ground conditioning is paramount for successful EPB tunneling in sand strata. Additives like bentonite slurry, foam and polymer are commonly used for ground conditioning in various sand strata, so as to guarantee safe and smooth tunneling. In the paper, the problems encountered during shield tunneling in sand strata in Nanchang, Zhengzhou and Xi’an are presented and the ground conditioning technologies used are described. The ground conditioning measures for shield tunneling in sand strata are summarized, and the stateofart of ground conditioning technology is discussed. 

Key words: EPB shield, and strata, round conditioning, dditives