Dynamic Response Characteristics and Instability Mechanism of High-Steep Bedding Rock Slope at the Tunnel Portal in High-Intensity Seismic Region

Western China is a typical high-intensity seismic zone, where seismic and geological disasters are frequent. The tunnel portal slope is prone to earthquake damage, which has become the key and difficult point in engineering construction. To deeply explore the dynamic response characteristics and instability mechanism of high-steep slopes at tunnel portal under frequent earthquakes, a large-scale shaking table test was designed. This experiment mainly simulates the geological environment of a high-intensity earthquake area by applying microseismic waves several times. The test results show that the amplification coefficient of peak ground acceleration (PGA) at different stages decreases with increasing earthquake intensity and finally presents a 50