Fundamental study on seismic stability of tunnels in weakly cemented soil and its countermeasures

弱胶结或非胶结土体中的隧道容易受到地震引起的地面运动或位移的破坏。为了研究这类隧道的复杂地震土-结构相互作用，人们发展了各种模型试验技术，如主动式剪力箱和断层模拟器。研究中考虑了三种特殊情况：1)浅埋隧道承受地表剪切变形；2)软弱地基隧道承受较大土压力；3)冲积层隧道承受断层位移。根据模型试验结果和数值模拟结果，分析了这些隧道的典型变形破坏机理，并探讨了有效的防治对策。

Tunnels in weakly cemented or no-cemented soils are susceptible to damages by ground motions or displacements caused by earthquake. In order to investigate complicated seismic soil-structure interaction of such tunnels, various model testing techniques has been developed, such as an active type shear box and a fault simulators. Three specific conditions were considered in this study, namely, 1) shallow tunnels which are subjected to shear deformation of grounds, 2) Tunnels in weak ground which is subjected to large earth pressure, and 3) tunnels in an alluvium subjected to fault displacement. From the model test results and numerical simulation, typical deformation and failure mechanism of these tunnels are scrutinized and effective countermeasures against them are discussed.