In order to effectively reduce the damage of transmission facilities such as substation and ensure the safety of transmission engineering,four representative rock slopes were selected as the research object.The propagation characteristics of ground motions with different lithology,topography and geology were studied.The amplification coefficients of slope under different terrain were preliminarily determined and compared with the seismic design codes (GB 50011-2010) (later referred to as the code) and the following understanding and conclusions were gotten.The sorting of the magnification coefficient calculated for the homogeneous and heterogeneous types is basically as upper soft lower hard rock > soft rock> medium hard rock > upper medium hard lower hard rock > hard rock.For covering soil layer rock slope,different thickness of the soil layer has a great impact on the magnification factor.The magnification coefficient of the weak intercalation rock slope is consistent with that of the homogeneous rock slope,but the former is basically larger than the latter,and is basically within 0.1,indicating that when the thickness of the weak interlayer is relatively small,the effect of weak interlayer on the magnification factor is independent of slope height,slope and lithology.The effect of different thickness of weak interlayer of the slope on the amplification factor is basically like a half sine form.By analyzing the Fourier spectrum of the top and the foot of the slope,it was found that the high slope has obvious amplification effect,while the low slope is not obvious.The Fourier amplitude of soft rock is obviously larger than that of medium hard rock and hard rock,and hard rock and medium hard rock are basically the same.Therefore,from the spectral characteristics,it can also explain the different lithology can lead to different site effects and the higher the slope,this difference is even more obvious.At medium and low height (below 80 m),the Fourier amplitude is almost constant with respect to the slope,and the maximum amplitude of the slow slope is substantially the same in this height range,and for high slope,it will be different.The steeper slope,the larger the amplitude,basically showing a linear increase trend.For the heterogeneous layers slope,the slope is different,the Fourier spectrum is not the same,and the main frequency band is not the same,which is different from the homogeneous slope; The Fourier spectra of the weak sandwich rock slope are basically the same as the Fourier spectra of the corresponding homogeneous slope.The Fourier spectrum of different interlayer thickness is basically the same,which indicates that the effect of interlayer thickness on Fourier spectrum is small and basically negligible.Compared with the specification,the magnification coefficient of homogeneous slope with the soft rock type is basically the same.For the medium hard rock,hard rock and upper medium hard lower hard rock types of slope,magnification coefficient is less than the standard value,indicating that the provision restrictions for the slope height and slope by specification are relatively small,and should increase the slope height and slope requirements.
