Dynamic Response Analysis Of The Seismic Load Of High And Steep Rock Slope In Gongchangling Open-pit Mine

With the development of social and economic technology,the continuous exploitation and utilization of resource energy,deep concave open-pit mining gradually become the development trend of the open-pit mine in our country,along with this way of mining formed a large number of high and steep rock slope.The dynamic response of high and steep rock slope under the action of dynamic load has important practical significance for its dynamic stability evaluation and control design.A section of the western end of Gongchangling He's mining area,which acts as the research object in this paper.It deeply studies the dynamic response of the section under the action of seismic load by using the FLAC3 D numerical simulation software.The main research work and conclusions are as follows:1.Selecting a section of the west end of upper plate,which is located in Gong Changling open-pit mining area.On this basis,the engineering geological mechanics model is generalized and the physical mechanical parameters of dynamic response analysis are determined.According to the characteristics of FLAC3 D dynamic response module and the actual situation of the research object,three seismic waves based on the record of strong seismograms are selected and the filtering and baseline correction processing is carried out using the Seismo Signal software.The mesh size of the precision condition is determined and the model is established using AUTOCAD-ANSYS-FLAC3 D.The boundary of dynamic response analysis is the free field boundary and the damping is Rayleigh damping.2.The dynamic response rules of slope horizontal direction,vertical direction and slope surface are analyzed under the action of horizontal seismic load.It is found that the horizontal amplification effect only occurs at a certain elevation and a certain range of the slope,the vertical approximation is linear elevation amplification effect,and the slope surface is nonlinear elevation effect.Taking the ground motion parameters as the starting point,the seismic wave type,seismic wave amplitude,frequency and the influence of the holding time on the dynamic response of the slope are analyzed.It is found that due to the different seismic waves have different spectral characteristics,the slope shows different dynamic response.With the increase of seismic wave amplitude,the peak amplification coefficient of the horizontal acceleration is decreasing in the soft rock,and the hard rock increases slightly.With the increase of seismic wave frequency,the peak amplification coefficient of horizontal acceleration is significantly reduced.The influence of the holding time on the dynamic response of the slope is not significant.3.The dynamic response of vertical and slope surfaces is analyzed by the coupling of horizontal and vertical seismic loads.The result shows that both of them were significantly stronger than the horizontal seismic load,especially the slope.The peak amplification coefficient of vertical acceleration also shows nonlinear height amplification effect.The a V/a H as an influential factor different from the ground motion parameters,the influence of this factor on the dynamic response of the slope is analyzed by adjusting the vertical seismic amplitude value and keeping the horizontal seismic amplitude unchanged.It is found that,in the vertical direction of slope,with the increase of vertical seismic amplitude,the amplification coefficient of horizontal acceleration in soft rock shows a decreasing trend,while in hard rock the opposite is true,while the dynamic response regularity of slope is not strong.With the increase of vertical seismic amplitude,the amplification coefficient of vertical acceleration peak shows a decreasing trend,which belongs to the vertical and slope in slope.By analyzing the acceleration Fourier spectrum curve of monitoring points in different rock mass medium,it is found that the slope has high frequency filtering effect,low-frequency amplification effect and selective amplification effect on the spectrum of incident seismic wave,and the spectrum spectrum near the natural frequency of slope increases significantly.