A 1 g shaking table test is conducted to investigate seismic responses of a segmental tunnel in sand under near-fault motions. The tunnel model is assembled with segments, bolts and rubber strips and embedded in a shallow sand ground. The test facility, design and preparation of the tunnel model and the sand ground, as well as selected earthquake motions, are presented in detail. Dynamic responses obtained from the experiment include accelerations of the sand ground and the tunnel model, strains of segments, diametric deformations of the tunnel section, as well as bolt tensions and rotation of radial joints. Results show that the ground fundamental frequency changes with different input motions due to sand nonlinearities, and the deformation of the segmental tunnel is concentrated on radial joints. Moreover, near-fault motions would significantly aggravate the seismic response of both the sand ground and the segmental tunnel compared to far-field motions. Physical mechanisms contributed to the observation that near-fault motions would lead to larger shear strains of ground, especially when the ground fundamental frequency decreases, are also discussed.

进行了 1 g 振动台试验，以研究在近断层运动下沙子中的管片隧道的地震响应。隧道模型由管片、螺栓和橡胶条组装而成，并嵌入浅沙地中。详细介绍了试验设施、隧道模型和沙地的设计和准备，以及选定的地震运动。从试验中获得的动力响应包括沙地和隧道模型的加速度、管片的应变、隧道断面的径向变形以及螺栓张力和径向接头的旋转。结果表明，由于砂土非线性，地基基频随输入运动的不同而变化，管片隧道的变形集中在径向节理上。而且，与远场运动相比，近断层运动会显着加剧沙地和管片隧道的地震响应。还讨论了物理机制有助于观察到近断层运动会导致更大的地面剪切应变，尤其是当地面基频降低时。