地铁盾构隧道与矿山法隧道接口段抗震计算研究

为确保地裂缝条件下地铁盾构隧道与地裂缝设防段矿山法隧道接口抗震设计满足要求,采用数值模拟与理论分析相结合的方法,针对西安地铁5号线某区间盾构隧道与地裂缝设防段矿山法隧道接口部位进行横向地震作用时程分析,并与横向地震作用的反应位移法结果进行对比,结合现有理论及规范,分析地铁隧道接口处的抗震性能及合理的计算方法,发现对于结构断面形式突变的地下结构,宜采用反应位移法进行强度及变形计算,同时采用时程分析法进行校核,明确了不同断面接口两侧隧道横向剪切刚度的差异是导致位移与变形差异的主要原因,同时提出减震层、管片柔性结构与弹性垫圈、变形缝以及加强钢筋与后浇环梁等抗震措施,在高烈度地区还可考虑将矿山法隧道设计为圆形或类圆形断面以提高整体抗震能力,研究结论可为类似工程提供参考。

Research on Seismic Calculation of Metro Interface between Shield Tunnel and Mined Tunnel

In order to ensure the compliance of the seismic design of interface between shield tunnel and mined tunnel with the relevant design requirements of ground fissures,numerical method and theoretic analysis are adopted specifically for the project of Xi'an metro line 5. The transverse seismic action analysis is conducted with time-history analysis method and response deformation method. With reference to the existing theory and norms,it is found that the underground structure of section mutation should adopt response-displacement method to calculate the strength and deformation,which are proved by time-history analysis method. The differences between different sections of the transverse shear stiffness of the interface on both sides of the tunnel are clarified and defined as the main cause for the differences in displacement and deformation. Such seismic fortification measures are also proposed as shock absorption layer,segment flexible structure and elastic washer,deformation joint,additional reinforcing steel and post pouring ring beam. In high seismic intensity regions,mined tunnels of round or oval cross-section may also be used to improve the overall seismic performance. The research results can provide reference for similar projects.