Large-scale Shaking Table Test Study On Dynamic Response Of Rock Slope In Shigat

In order to study the dynamic response of rock slopes under earthquake in cold,high-altitude and seismic areas,this paper takes the rock mass composite structure of typical slopes in Shigatse area as the simulation feature,and designs and completes large-scale shaking table tests by using four composite conceptual models composed of forward and reverse slopes in normal environment and freeze-thaw environment respectively.The dynamic response characteristics of the model under seismic wave action on jointed rock slope are revealed by drawing the variation rules of parameters under different working conditions in the process of slope failure.The main results are as follows:(1)In the frozen-thawed slope model,the PGA on the slope surface increases with the elevation,and the amplification coefficient increases with the elevation under the action of unidirectional seismic wave.(2)Under the action of unidirectional seismic force,the peak acceleration and amplification coefficient at the top of rock slope under freeze-thaw environment are larger than those at the middle part of slope.(3)Under normal environment,the variation characteristics of peak acceleration and amplification coefficient at the top of rock slope with elevation are slightly different,which are embodied in the downward direction.When the loading amplitude is larger than 0.5g in inclined slope,the change characteristics of PGA and its amplification coefficient with elevation are opposite to those with small amplitude,while in Anti-inclined slope,the change characteristics of PGA and its amplification coefficient with elevation increase are basically the same as that with elevation increase.(4)Under different climatic conditions and the same working conditions,the PGA and the amplification coefficient of rock slope model have no obvious law no matter under the action of X or Z seismic forces;(5)Under natural seismic wave conditions,the peak acceleration of rock slope increases with the increase of amplitude,while the magnification factor shows obvious piecewise characteristics according to the magnitude of loading amplitude,and the amplitude is less than 0.4g.From 0.4g amplitude,the amplification coefficient of PGA increases anddecreases repeatedly,but in general,the peak acceleration and amplification coefficient also show an increasing trend with the increase of amplitude.(6)The direction of seismic wave loading has obvious influence on the peak acceleration and amplification coefficient of rock slope.In the inclined slope,the effect of vertical seismic wave action on PGA is greater than that of horizontal seismic wave action,while in the Anti-inclined slope,the effect of horizontal seismic wave on amplification coefficient is greater than that of vertical seismic wave action on amplification coefficient.