济南粉质黏土中隧道地震动力响应试验研究

为了解济南典型地层及地铁隧道结构的地震动力响应特性,进而把握地铁隧道的抗震性能,首次使用济南粉质黏土作为模型土,开展了一组济南人工波输入情况下的振动台模型试验。试验结果显示:人工波在试验地层中加速度放大系数随测点埋深呈现反“之”字形规律;隧道结构变形主要受地层变形控制,地层水平变形随埋深增大而减小;济南粉质黏土层自振频率随着输入地震波强度增大而减小,阻尼比随输入地震波强度增大而增大。砂层自振频率随着输入地震波强度增大呈现先减小后增大的趋势,阻尼比呈现先增大后减小的趋势。这些结果可对济南地铁隧道的抗震设计提供重要的参考。

Experimental Study on Seismic Response of Ji'nan Silty Clay and the Tunnel in It

In order to understand the seismic dynamic response characteristics of Ji'nan strata and tunnel structure under Ji'nan wave action, Ji'nan silty clay undisturbed soil was used as model soil for the first time. The shaking table model test was used to study the seismic dynamic response of the Ji'nan silty clay and the tunnel in it. The test results show that the acceleration amplification factor of the Ji'nan wave in the test stratum exhibits an inverted “Z” pattern with the buried depth of the measuring point; the deformation of the tunnel structure is mainly controlled by the deformation of the surrounding soil, and the horizontal deformation of the stratum decreases with the increase of the buried depth ; The natural vibration frequency of the clay layer decreases with the increase of the intensity of the input seismic wave, and the damping ratio increases with the intensity of the input seismic wave. The frequency of natural vibration of the sand layer decreases first and then increases with the increase of input seismic intensity, and the damping ratio increases first and then decreases.