Dynamic response analysis of submerged floating tunnel after anchor cables forces adjustment under impact load

Abstract

Submerged Floating Tunnel (SFT) is a new type of cable-supported structural system for straight crossings. In this study, the initial state of the SFT was optimized based on the existing SFT cable-force adjustment method (relatively uniform cable forces, minimizing the support reaction forces at the abutment section). The responses of the SFT under static and seismic conditions before and after cable-force adjustment were compared, further verifying the optimization effect of the cable-force adjustment method on the structural performance of the SFT. In addition, a theoretical model (flexible support model) of the anchor cables was proposed to calculate the displacement after impact by sunken ships. A finite element model of the SFT was established using ABAQUS to prove the accuracy of the flexible boundary model. In addition, the flexible support stiffnesses of anchor cables at different positions were determined based on the finite element model. Finally, the SFT after the cable-force adjustment was analyzed to study the response patterns of the anchor cables at different positions under an impact load. The results demonstrate that a correlation between the distribution pattern of the flexible boundary stiffnesses of anchor cables and the regulation of the responses of the anchor cables to impact load.