Prediction of the additional structural response of segmental tunnel linings induced by asymmetric jack thrusts

The important role of stiffnesses values of circular joints on the stress state developed in the tunnel segmental lining

“…The finite element analysis (one type of the numerical method) is sophisticated and time-consuming, but is widely used due to its capability of detailed simulation for the segmental lining, such as bolts, concrete segments, hydraulic jacks, jack pad, shield tail wire brush, etc. (Chaipanna and Jongpradist 2019;Gil Lorenzo 2021;Guo et al 2021;Shi et al 2022;Wang et al 2014;Zaheri et al 2020).…”

“…Huang et al (2012), Talmon and Bezuijen (2013), Huang et al (2015) and Gil Lorenzo (2019) (2023) 9:37 the longitudinal continuous model based on the Euler-Bernoulli beam and analysed the longitudinal deformation and the internal forces. However, the Euler-Bernoulli beam can't represent the shear deformation; the continuous Timoshenko beam was used to calculate the longitudinal deformation considering the bending stiffness and the shear stiffness (Cheng et al 2021;Shi et al 2022;Wu et al 2015Wu et al , 2018. Although the CB model was used widely as a result of the convenience, it is difficult to accurately reflect the deformation characteristic of joints after considering the discontinuous segmental lining as an equivalent continuous beam (Li et al 2014).…”

“…In order to quickly and simply assess the differential deformations of the tunnel lining along the longitudinal direction, 1D simplified analytical models were developed based on the beam theory which adopt the bending stiffness and the shear stiffness to control the longitudinal deformation (Cheng et al 2021;Li et al 2019;Liang et al 2017;Liao et al 2008;Liu et al 2021;Shi et al 2022;Shiba et al 1989;Wu et al 2015;Yu et al 2019). Because the stiffness is an equivalent value that is influenced by the material of the segmental lining, the shape of its cross section and the presence of forces, especially for the joints, the evaluation method of the stiffness is controversial and also in continuous improvement (Cheng et al 2021;Wu et al 2015).…”

“…Geng et al (2019) divided the deformation of the circumferential joint into five different patterns based on the contact state of the joint and the stress state of bolts, and found that the combination of tension force and moment influence the equivalent bending stiffness. Shi et al (2022) considered a nonlinear equivalent bending stiffness of joints under the application of axial forces, and found that the deformation of joints shows a two-stage increase with the increase of the moment. Based on the findings of researchers, the axial force in the lining has an obvious impact on the bending stiffness, and the relationship between them is nonlinear and not explicit.…”

Evaluation of the Ground Settlement in an Urban Area Resulting from a Small Curvature Tunneling Construction

“…Compared to straight line tunnels, small curvature tunnels have more critical factors (asymmetric jacking force, overcutting gap, and face stability, etc. ), which wreak havoc on tunnel safety [2,3]. The main challenge faced by many researchers is how to control stratum deformation induced by a small curvature.…”