Study on Dynamic Response Characteristics of Slope with Double-Arch Tunnel Under Seismic Action

Abstract

To study the seismic dynamic characteristics of the slope with double-arch tunnel, a large-scale shaking table model test of slope with double-arch tunnel whose scale is 1:20 was designed and finished. A series of tests were performed with different excitation direction seismic waves including WC, EI and Kobe seismic wave whose peak are 0.1 g, 0.2 g, 0.4 g, 0.6 g. The influence of seismic wave type and excitation intensity on the dynamic response of the slope with double-arch tunnel were discussed. The results show: (1) As the slope height increases, the acceleration amplification coefficient shows a non-linear trend. The acceleration response characteristics of the slope under WC-XZ excitation are different from those of K-XZ and EI-XZ. (2) Different types of rocks have different amplification effects on acceleration. At the rock mass interface, the acceleration amplification effect is more obvious. (3) The acceleration magnification factor at the top of the slope is relatively large, which is susceptible to earthquake damage, rock ejection and other damage phenomena. (4) The slope has a filtering effect on the high frequency band of seismic waves. (5) The peak value of the dynamic displacement response of the slope increases non-linearly with the increase of the slope height. The peak of the dynamic displacement response at the top of the slope is large, while the peak of the vertical displacement at the foot of the slope is large. (6) The response characteristics of slope acceleration and dynamic displacement under earthquake are related to the type of seismic wave, the location of the measuring point, and the nature of the rock mass. Significance guidance for seismic study on the slope with double-arch tunnel was provided.