Abstract Assuring the stability of a tunnel face has always been one of the technical difficulties regarding shield tunnels in mixed ground. The Singapore Metro loop line is located in this type of earth, and for this project a slurry earth pressure balance shield was adopted in large scale for the first time. Based on Singapore Metro Lot C855, this paper discusses the stability of the excavated face and the setting of slurry pressure during the slurry shield construction in mixed ground. In addition, it introduces the concept of the stability coefficient Ns in light of the spheroid model proposed by Anagnostou and Kovari. The analysis and calculation of the slurry pressure of the excavated face along the line are also addressed. Moreover, a table of slurry pressure settings is given concerning such factors as equipment performance, ambient conditions, site organization and execution. Finally, the paper analyzes the problems encountered during construction, including the collapse of the excavated face, slurry running and precipitation.
Abstract：
Assuring the stability of a tunnel face has always been one of the technical difficulties regarding shield tunnels in mixed ground. The Singapore Metro loop line is located in this type of earth, and for this project a slurry earth pressure balance shield was adopted in large scale for the first time. Based on Singapore Metro Lot C855, this paper discusses the stability of the excavated face and the setting of slurry pressure during the slurry shield construction in mixed ground. In addition, it introduces the concept of the stability coefficient Ns in light of the spheroid model proposed by Anagnostou and Kovari. The analysis and calculation of the slurry pressure of the excavated face along the line are also addressed. Moreover, a table of slurry pressure settings is given concerning such factors as equipment performance, ambient conditions, site organization and execution. Finally, the paper analyzes the problems encountered during construction, including the collapse of the excavated face, slurry running and precipitation.
XIAO Xiao-Chun
.Analysis of the Excavation Face Stability and Slurry Pressure Setting in the Singapore Metro Lot C855[J] MODERN TUNNELLING TECHNOLOGY, 2012,V49(1): 20-26
2012, Vol. 49 