Longitudinal shock absorption performance of energy dissipation prestressing joint between shield tunnel rings

Abstract

To address the issue of damage and failure of circumferential joints in shield tunnels under strong earthquakes, this study proposes an energy dissipation prestressing joint (EDPJ) installed between shield tunnel rings. The basic structure and design method of the EDPJ are given. The mechanical properties of the main energy dissipation elements are tested by means of quasi-static experiments. A refined three-dimensional numerical model is developed to study the hysteresis behaviour of EDPJ. The damping performance of tunnels applying EDPJ is evaluated based on the generalised response displacement method. The results demonstrate that the damping force generated by the energy dissipating element of EDPJ is consistently stable, and the hysteresis curve shows a full rectangle. The EDPJ exhibits a well capacity for energy dissipation under cyclic loading, with a notable reduction in concrete damage, internal force, and opening width. The opening width between shield tunnel rings with EDPJ is significantly reduced for different earthquake magnitudes. The suitable arrangement of the EDPJs and the increase of the prestressing levels contribute to the improvement of the seismic damping effect of the joints. This study can provide reference for the design of longitudinal damping measures for shield tunnel engineering.