Abstract:

The construction of the vertical shafts and the shield launching sections of Nanjing Weisanlu Yangtze River Crossing Tunnel produced a huge amount of waste clay. On the other hand, 40% of the shieldbored section of the mentioned tunnel is located in fine silty sand strata, which requires that the slurries to be used need not have high performance. As a result, the waste clay produced is reused to prepare slurries for slurry shield boring. The waste clay is mixed with fill, muddysilty clay and bentonite to prepare slurry. The filter loss and filter membrane quality of the slurry prepared are tested by means of selfmade slurry infiltration testing device. The mixing proportion of the slurry is verified by the site monitoring data. The study shows that the mentioned slurry with waste clay mixed has such advantages as good stability, compact filter membrane and low slurry loss, and it can meet the requirements of shield boring in fine silty sand strata.

Key words: Nanjing Weisanlu Yangtze River Crossing Tunnel, waste clay, fine silty sand strata, slurry, filter membrane