Geotechnical Engineering Journal of the SEAGS & AGSSEA ISSN 0046-5828
Vol. 46 No.3 September 2015
Soil Deformation Induced by Underground Tunnel Construction
L. Wang1, *R. Liu2, and G. G. Wang3
1,2State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China
3The Third Railway Survey and Design Institute Group Corporation, Tianjin 300142, China
Email: 375217932@qq.com
ABSTRACT: Development and utilization of underground railways can effectively ease the problem of urban traffic congestion. However, surrounding soil disturbance during tunnel excavation is likely to cause serious accidents. Thus, analyzing soil deformation during tunnel excavation is important. Through numerical simulation, this paper analyzes the influence of the step distance of a single-bore tunnel on the disturbance of the surrounding soil. Based on research on a single-bore tunnel, this paper further examines the effects of various spacing, locations, and excavation methods on the deformation of surrounding soils during parallel tunnel excavation. The results show that longer excavation steps lead to more intense disturbance to the surrounding soils. The most intense disturbance occurs at the ends of the tunnel. During new tunnel excavation, the tunnel crossing angle has stronger influence than the tunnel spacing on the original tunnel. Among the four excavation methods, single-bore advanced through is the most secure, whereas simultaneous excavation from opposite directions can cause the most intense disturbance to the surrounding soils. In practical operations, corresponding excavation methods can be employed according to specific conditions. Moreover, in-situ monitoring at key positions should be enhanced to avoid accidents.
KEYWORDS: Parallel tunnels; Numerical simulation; Excavation space; Tunnel spacing; Tunnel crossing angle; Soil deformation
