Abstract

Tunnels in the junction of the soft and hard rock always suffer severe damages during the strong earthquakes. This article aims to investigate the seismic effect of the combination of the buffer layer and the steel fibre reinforced concrete (SFRC) linings in tunnel seismic design. Firstly, taking the soft and hard rock junction of Fanjiazhai Tunnel as the research background, the finite difference calculation models considering the modified seismic motion, the mechanical damping, the safety factor and the seismic materials are established to study the seismic response of the tunnel crossing the soft and hard rock junction. Then, the buffer layer and the SFRC lining are applied into the soft-hard rock junction tunnel respectively, the isolation performance of the buffer layer and the strengthening effect of the SFRC lining are analyzed by using the seismic displacement, seismic acceleration and the safety factor. Finally, the combination of the buffer layer and the SFRC lining is employed in the tunnel located in soft-hard rock junction, the effectiveness and the synergistic effect of combination method are proved by numerical analysis. The research results can provide references for seismic fortification of the tunnel crossing soft and hard surrounding rock junction in meizoseismal area.

摘要

在强地震中，软硬岩石交界处的隧道总是遭受严重破坏。本文旨在研究在隧道抗震设计中缓冲层和钢纤维混凝土衬砌组合的抗震效果。首先，以范家寨隧道的软，硬结为研究背景，建立了考虑修正地震运动，机械阻尼，安全系数和地震材料的有限差分计算模型，以研究隧道穿越时的地震反应。软硬岩石交界处。然后，将缓冲层和SFRC衬里分别施加到软硬岩石结隧道中，利用地震位移，地震加速度和安全系数，分析了缓冲层的隔离性能和SFRC衬砌的加固效果。最后，在软硬岩石交界处的隧道中采用了缓冲层和SFRC衬砌的组合，通过数值分析证明了组合方法的有效性和协同效果。研究结果可为中震地区软硬围岩交界处的隧道抗震设防提供参考。数值分析证明了组合方法的有效性和协同作用。研究结果可为中震地区软硬围岩交界处的隧道抗震设防提供参考。数值分析证明了组合方法的有效性和协同作用。研究结果可为中震地区软硬围岩交界处的隧道抗震设防提供参考。