Load Increasing Method For Analysis Of Loess Slope Earthquake Stability In Baoji

In recent years, many earthquakes happened all over the world, such asWenchuan earthquake, Yushu earthquake and the east coast of Japan earthquake, etc.These large earthquakes are shocking by the sight of the earthquake disaster, such asthe seismic landslides is the great earthquake disaster with large damage. The tragedyof seismic landslides requires people to strengthen the research of slope dynamicstability in order to effectively aseismatic fortify.With the Baoji region’s complex geological structure, different topography andgeomorphology, the distribution of slope widely, and the influence of Fen wei seismiczone, Liu Pan-Qi lian mountain seismic zone, Han jiang river seismic zone and Ordosregion seismic zone to Baoji region, seismic slope stability research is necessary inBaoji.The strength reduction is a common method of studying the stability ofearthquake slope,which fix the seismic load to search the slope’s critical strength bychanging the strength of slope. The critical strength and the current strength canmeasure the level of slope’s reserve strength, which provides the basis for seismicfortification. The method has already written into the related standards, but itself hassome limitations. In this paper, load increasing method is a new method, which fix thestrength to search the critical acceleration by changing the acceleration.Compared tothe regional seismic fortification criteria,it can evaluate the slope stability and whetherseismic fortification is safe, which provides the basis for seismic fortification, so itcan be called the overload dynamic stability of the slope. Because the load increasingmethod is proposed lately, and it is still in the stage of exploration, there is not projectstandards and analysis method need be discussed in depth. This paper bases on theprevious studies, through the examples, to research the load increasing method deeplyin order to perfect it.This paper chooses Pan Long yuan slope as the research object.Basing on theload increasing method, at first it need search the suitable earthquake accelerationschedule for the baoji region.According to the method of pseudo static force, it need estimate a critical load of the slope which cannot destruct the slope, and it may beinitial load to search the critical load from weak to strong, then comparing toaseismatic fortify earthquake acceleration of the baoji region to define the safty factorof the slope dynamic stability, which is stability criterion and provides the basis forthe seismic fortification of slope. By the overload analysis of Pan Long yuan slope,the safty factor is0.67, which may suffer demage in the earthquake with exceedingprobability10%in coming50years.Through the study, this paper furtherly perfect theload increasing method，which provide the basis of building the assessment system ofearthquake slope stability.