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通过大型振动台对隧道-围岩模型箱施加卧龙波波形的地震荷载,研究隧道衬砌穿越断层破碎带的动力响应特性。试验结果表明,在地震荷载作用下,穿越断层破碎带的隧道衬砌对地震荷载的响应存在一定的时间延迟,试验结果为0.085 s。围岩和模型箱对地震加速度有一定的放大作用,表现为在沿垂直振动台台面方向上,距离振动台台面越远,地震荷载的放大越明显。隧道衬砌在受到水平方向的地震荷载作用时,由于断层破碎带岩土体能够提供的抗力较低,致使断层两侧的围岩产生相对运动、碰撞、挤压等,从而导致衬砌出现斜向裂缝。试验结果与汶川地震的震后调查结论相一致。针对振动台模型试验方案中存在的一些问题如边界效应、模型箱刚度等提出了改进意见。
The seismic load of Wolong wave is applied to the tunnel-surrounding rock model box through a large shaking table to study the dynamic response of the tunnel lining through the fault fracture zone. The test results show that there is a certain time delay in the response of the tunnel lining crossing the fault zone under the earthquake load to the seismic load, and the test result is 0.085 s. The surrounding rock and the model box have a certain magnifying effect on the seismic acceleration, which shows that the farther away from the table of the vibrating table in the direction along the vertical vibrating table, the more obvious the magnification of the seismic load. When the tunnel lining is subjected to the horizontal seismic load, the relative resistance, collision and extrusion of the surrounding rock on both sides of the fault will be caused due to the lower resistance provided by the rock and soil mass in the fault fracture zone, resulting in oblique cracks in the lining . The test results are consistent with the post-earthquake survey results of the Wenchuan earthquake. Aiming at some problems existing in shaker model test program, such as boundary effect and rigidity of model box, some suggestions are put forward.