Research On Seismic Dynamic Response Characteristics Of Ridge Topography Slope Of Xishan Park In Zigong

The investigation and research results of a large number of slope damages induced by strong earthquakes show that the slope site conditions have a significant influence on the characteristics of ground motion response,especially the factors such as mountain topography and stratum have a strong influence on slope ground motion,which is also a hot research topic in the field of seismic engineering at home and abroad.However,slopes often have limited understanding of their dynamic response studies due to lack of monitoring data for strong earthquakes in the near field.This article takes the slope of Xishan Park in Zigong as the research object,and based on the acceleration data of the Wenchuan earthquake and Changning earthquake recorded by the seismic monitoring array on the slope,based on the analysis and understanding of the seismic monitoring data,a series of environmental noise tests were carried out at the same time.The environmental noise data of the slope in spring,summer,autumn,and winter are analyzed in the horizontal and vertical spectral ratio method?HVSR?and standard spectral ratio method?SSR?,and the numerical simulation method is used to systematically study Zigong Ground response characteristics of ridge terrain slopes in Xishan Park.The main research results are as follows:?1?The smaller amplitude of the Wenchuan earthquake in the soil layer?0#?site is stronger than the bedrock?1#?7#?site.The spectral magnification factor of the layer site is about 6.5,and the horizontal superior frequency is about 7.5 Hz.With the slope topography and elevation increase,the dynamic amplification effect of the 6#bedrock monitoring site at the top of the slope is stronger than other monitoring points on the slope.Local topography,slope,and elevation factors have certain effects on the site amplification effect.?2?Analysis of environmental noise data revealed that the spectral response characteristics of site ambient noise were hardly affected by seasonal temperature difference,and the spectral ratio curve was relatively stable;the weak clay cover layer showed a significant amplification effect on the ground motion in the lower frequency band;comparison with the results of seismic data analysis showed the two types of data have better frequency coupling effects at the protruding parts?5#?7#?where the terrain has a strong amplification effect,and the ambient noise of the spectral amplification factor is smaller than the results of seismic monitoring.?3?Further use of mapping techniques and geophysical prospecting methods to obtain high-precision terrain data of slopes and wave velocity parameters of formation media,etc.,and the use of two-dimensional?UDEC?discrete element program to construct slope pure terrain?homogeneous reference model?and terrain combined stratum model reveal,combined model The amplification effect is much larger than the homogeneous model,and it has good coupling characteristics with the amplification effect of seismic monitoring data analysis.?4?The results of the three-dimensional(FLAC^3D)numerical simulation analysis show that the slope model has different amplification effects under different seismic loads,but does not affect the site's excellent frequency;the results of the three-dimensional model stress and displacement analysis show that the dynamic response of the area near the top of slope is strong,under the action of strong vibration,there may be a risk of shear failure on the slope surface.This study has important theoretical value and engineering significance for understanding the site response characteristics of ridge terrain slope under different earthquake intensity.