Abstract The integrity and reliability of shield-tail sealing are very important to the safety of shield tunnelling, and tail-seal brushes need to be replaced quickly in case of any damage; therefore the sealing of underground water is key to success in these cases. Taking line N of the Nanjing Weisan Road river-crossing project as an example, and considering the characteristics and requirements of replacing a tail-seal brush in a strong, permeable strata with high water pressure, an improved grouting technique was adopted for stopping water: 1) the primary water-stopping system was formed by strengthening the synchronous grouting; 2) the shield-tail part was consolidated by grouting via two special segments with additional reserved holes; and 3) the B-ring of the shield was grouted with polyurethane to avoid leakage from the front of the slurry chamber. Using this method, a complete water-sealing system characterized by its thickness, high density and strength is formed, ensuring successful replacement of the tail-seal brushes in a dry environent.
Abstract：
The integrity and reliability of shield-tail sealing are very important to the safety of shield tunnelling, and tail-seal brushes need to be replaced quickly in case of any damage; therefore the sealing of underground water is key to success in these cases. Taking line N of the Nanjing Weisan Road river-crossing project as an example, and considering the characteristics and requirements of replacing a tail-seal brush in a strong, permeable strata with high water pressure, an improved grouting technique was adopted for stopping water: 1) the primary water-stopping system was formed by strengthening the synchronous grouting; 2) the shield-tail part was consolidated by grouting via two special segments with additional reserved holes; and 3) the B-ring of the shield was grouted with polyurethane to avoid leakage from the front of the slurry chamber. Using this method, a complete water-sealing system characterized by its thickness, high density and strength is formed, ensuring successful replacement of the tail-seal brushes in a dry environent.
.Application of Grouting and Water-Blocking Techniques to the Replacement of Shield Tail Seal Brushes in a Permeable Strata with High Water Pressure[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(4): 190-194
2015, Vol. 52 