2D numerical investigation of segmental tunnel lining behavior

• Published in: Tunnelling and underground space technology 2013-08, Vol.37, p.115-127
• Main Authors: Do, Ngoc-Anh, Dias, Daniel, Oreste, Pierpaolo, Djeran-Maigre, Irini
• Format: Article
• Language: English
• Subjects: Applied sciences; Bending moments; Buildings. Public works; Computation methods. Tables. Charts; Concretes; Displacement; Earth; Exact sciences and technology; Joint stiffness; Lining force; Mathematical analysis; Mathematical models; Numerical model; Reduction; Segmental lining; Shield-driven tunnel; Shields; Space technology; Stiffness; Structural analysis. Stresses; Tunnelling; Tunnels (transportation); Tunnels, galleries; Two dimensional; Underground
• ISSN: 0886-7798; 1878-4364
• DOI: 10.1016/j.tust.2013.03.008

•The joint number increase results in a higher flexibility of the tunnel structure.•The tendencies of bending moments for odd or even joint number cases are opposite.•The axial and radial stiffness of the joint have an insignificant impact.•The high deformability of the soil increase the flexibility of the segmental tunnel lining.•The influence of the joint number on the bending moment depends on the K0 value. The application field of shield tunneling has extended in recent years. Most shield-driven tunnels are supported by segmental concrete linings. Although many well documented experimental, numerical and analytical results exist in literature concerning the functioning of segmental tunnel linings, their behavior under the influence of joints is still not clear. This paper presents a numerical study that has been performed to investigate the factors that affect segmental tunnel lining behavior. Analyses have been carried out using a two-dimensional finite difference element model. The longitudinal joint between segments in a ring has been simulated through double node connections, with six degrees of freedom, represented by six springs. The proposed model allows the effect of not only the rotational stiffness but also the radial stiffness and the axial stiffness of the longitudinal joints to be taken into consideration. The numerical results show a significant reduction in the bending moment induced in the tunnel lining as the joint number increases. The tunnel behavior in terms of the bending moment considering the effect of joint distribution, when the lateral earth pressure factor K0 is equal to 0.5, 1.5 and 2, is almost similar and differs when K0 is equal to unity. It has been seen that the influence of joint rotational stiffness, the reduction in joint rotation stiffness under the negative bending moment, the lateral earth pressure factor and Young’s modulus of ground surrounding the tunnel should not be neglected. On the other hand, the results have also shown an insignificant influence of the axial and radial stiffness of the joints on segmental tunnel lining behavior.