Experimental Study On Dynamic Response Of "the-segment" Rock Slope

In recent years,the research on the stability of rock slope under earthquake is one of the hot topics in geological engineering and geotechnical engineering.Earthquakes are one of the most common and harmful natural disasters.Their primary and secondary disasters are huge.They are the main factors inducing landslides,collapses and debris flows.They greatly threaten people's life and property safety,and seriously damage the national economic construction.Earthquake disasters occur frequently in China,and there are a large number of Alpine landforms in southwest China.With the deepening development of the Western Regions and the rise of Southwest China,the problem of earthquake disasters has become increasingly prominent,affecting the implementation of infrastructure construction and the development of Engineering projects.This is one of the major challenges in the construction of the western region.There are many "three-segment" clavicular landslides in southwest China widely.In order to explore the theoretical basis for the formation and development of earthquake disasters and provide engineering practical significance for earthquake prevention and earthquake resistance,it is very important to strengthen the study of dynamic response law of "three-segment" rock slope under earthquake action.Based on shaking table model test,PGA data at different locations under different working conditions are collected,analyzed and studied in this paper,and the dynamic response law of "three-segment" rock slope are as follows:(1)Through shaking table tests on model slopes,it is found that under different input waves,the acceleration amplification coefficients of the measured points on the slope surface and in the slope increase with the increase of the slope height,showing the elevation amplification effect as a whole,approximating to linear amplification along the slope surface,and increasing "fish belly" in the same vertical direction within the slope;at the same elevation measuring point,the acceleration at the measured points on the slope surface increases.The magnification factor is always greater than the acceleration magnification factor of the measured points inside the slope,showing a trend table effect.(2)Sinusoidal wave and El Centro wave are used to excite the slope during the test.By comparing the law of the variation of the acceleration amplification coefficient at the slope surface under different input waves,it is concluded that there are obvious differences in the variation of the acceleration amplification coefficient between the input wave waveforms,which generally shows the amplification system of sinusoidal wave at the same measuring point.The number of seismic waves is significantly higher than that of El Centro seismic waves,which is due to the difference in the number of peak values of seismic waves in the input process.In addition,by changing the loading amplitude and frequency of the same waveform,it is found that with the increase of amplitude and frequency,the acceleration amplification coefficient increases first and then decreases.(3)Through seismic wave excitation of slope models of different structural types,it is found that the existence of creep section makes the acceleration amplification effect of the lower measuring points of the structure slightly increase,because the seismic wave refracts and scatters in the creep section during the propagation process.The acceleration amplification factor of the measured points in the upper part of the creep section is smaller than that of the homogeneous slope.The reason is that the creep section material in the single creep section slope model is different from that of the slope body material,and there exists a large filtering effect at its interface due to the change of the material.In addition,the existence of cracks also reduces the acceleration amplification factor of the measured points nearby.