Analysis of the Mechanical Behavior of Segments of the Shield-driven Metro Tunnel beneath River Bottom
(1 Key Laboratory of Highway Engineering Ministry of Educationin Special Areas, Chang′an University, Xi′an 710064; 2 Management Department of the First Phase of CCCC Foshan Urban Rail Transit Line 2, Foshan 528000)
Abstract:
Compared with other sections of a shield tunnel, the engineering geology and hydrogeological conditions of the shield tunnel section passing through river are more complex, especially in southern China where the seasonal precipitation is large, the surface and underground water levels change obviously. Taking certain section of the shield tunnel on Foshan metro line 2 as the research object, it carries out a numerical analysis on segments usingAbaqus finite element software based on a beam-spring model, and verifies with the measured axial forces of segments. The results show the earth pressure on segment is slightly smaller than that calculated by the full-covered earth pressure method; water pressure around the shield tunnel has great influence on internal force of segment, the fissure water and confined water in rock stratum should be taken into account in the design of segment even if the rock layer above shield tunnel is poor in water permeability,and the earth pressure acting on segment is calculated with the full-covered earth pressure for the sake of security.
ZHANG Bingwu1 ZHANG Peng1 DAI Zhenhua2 WU Yinghe2 LUO Wei2
.Analysis of the Mechanical Behavior of Segments of the Shield-driven Metro Tunnel beneath River Bottom[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(3): 85-90