Numerical study on shearing performance of seel plate strengthened circumferential joints of segmental tunnel linings

The safety of operated shield-driven tunnels is threatened by the risk comes from the existing displacement between the adjacent segmental linings at the position of circumferential joints. The additional steel plate strengthening has shown as a probably effective way to improve the performance of the joints of displaced segments. The finite element method (FEM) is adopted to simulate the segment joints strengthened by steel plate. A 3-dimensional FE model containing two segments connected by a curved bolt is first established. Then a numerical test is designed and conducted to demonstrate the effectiveness of the proposed steel plate strengthening method. Based on the simulated results, the relationship between joint displacement and external load is illustrated, and the tendency of which is explained by the stress analysis of the contacted elements within bolts and segments. Next, by comparing the displacement increase between joints with and without steel plate reinforcement, the strengthening efficiency of steel plate on the displaced segment joint is discussed. Finally, the interaction mechanism is investigated by analyzing the stress distribution at the interface between the steel plate and the linings. After all, some suggestions are offered for the real world engineering practice.