RESEARCH ON THE COMBINED DAMPING TECHNOLOGY OF SHALLOW BURIED LARGE-SECTION LOESS TUNNEL

Due to the unique characteristics of loess and the higher seismic performance requirements for tunnel engineering, researching the seismic response of loess tunnels with vibration reduction measures is essential.This study is based on the Xicheng Mountain Tunnel project, employing finite element software to establish a three-dimensional numerical model.It analyzes the stress and strain responses of the structure under different spacing of shock absorption joints and varying stiffness of the lining.A combination of rigid lining + shock absorption joint is proposed, and the effectiveness of this combined vibration reduction strategy is further analyzed.The results indicate that installing shock absorption joints can significantly reduce the dynamic response of loess tunnels during seismic activity, with a recommended joint spacing of 10 meters, which can reduce maximum structural stress by up to 46%.Different lining stiffness leads to varied dynamic responses; as stiffness increases, structural stress rises, while deformation decreases.A rigid lining can increase structural stress by 28.7%, but can also reduce strain by 47.5%.The combined approach of rigid lining + shock absorption joint effectively harnesses the advantages of individual vibration reduction measures, reducing both stress and strain, thereby mitigating seismic risks to loess tunnels. © 2024 Czech Technical University in Prague. All rights reserved.