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3D FEM Analysis of the Positive Bending Capacity for Rectangular Shield Tunnel Segment Joints with a Connector Box
(1 School of Highway, Chang′an University, Xi′an 710064; 2 Department of Geotechnical Engineering, Tongji University, Shanghai 200092; 3 Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University, Shanghai 200092;4 Shanghai Urban Construction Design & Research Institute, Shanghai 200011)
Abstract A large bending moment with a small axial force brings big challenges to the structural design of largesection rectangular segment joints. As one kind of embedded part, the connector box′s design and mechanical mechanism should be studied since the force is also shared by the concrete. As for a beam-spring model, the bending resistance rotational spring stiffness presents obvious nonlinear behavior and is presently acquired mainly by fullscale mechanical tests of the segment joint. Because of the convenience of FEM simulation, a fined 3D calculation model of the rectangular shield tunnel segment′ s longitudinal joint with a connector box was established by ABAQUS based on the mechanical test data. The rationality of the joint structure design was reviewed under the positive moment, the influence of the axial force on the positive bending capacity of the segment joint was studied and the segment joint failure mode was analyzed. The results show that the bending moment-rotation curve can be simplified as a triple-line model; in a certain range, the axial force can effectively delay the plastic and destructive processes of the segment joints while it has little influence on the numerical values of the bending stiffness at different stages.
Abstract：
A large bending moment with a small axial force brings big challenges to the structural design of largesection rectangular segment joints. As one kind of embedded part, the connector box′s design and mechanical mechanism should be studied since the force is also shared by the concrete. As for a beam-spring model, the bending resistance rotational spring stiffness presents obvious nonlinear behavior and is presently acquired mainly by fullscale mechanical tests of the segment joint. Because of the convenience of FEM simulation, a fined 3D calculation model of the rectangular shield tunnel segment′ s longitudinal joint with a connector box was established by ABAQUS based on the mechanical test data. The rationality of the joint structure design was reviewed under the positive moment, the influence of the axial force on the positive bending capacity of the segment joint was studied and the segment joint failure mode was analyzed. The results show that the bending moment-rotation curve can be simplified as a triple-line model; in a certain range, the axial force can effectively delay the plastic and destructive processes of the segment joints while it has little influence on the numerical values of the bending stiffness at different stages.
.3D FEM Analysis of the Positive Bending Capacity for Rectangular Shield Tunnel Segment Joints with a Connector Box[J] MODERN TUNNELLING TECHNOLOGY, 2018,V55(4): 122-131
2018, Vol. 55 