Research On Kinematic Characteristics Of Seismic Landslide Of Liquefied Loess

The loess Plateau has a complex geological and structural background with frequent strong earthquakes.Earthquake and landslide disaster has long threatened people's lives and restricted economic and social development.Loess seismic landslides are of various types and their genesis is complex and varied.The liquefied-loess seismic landslide needs more attention because of its long slip distance,low slope and strong destructive ability.At present,there is a lack of research on the development mechanism of loess seismic landslides and the characteristics of liquefied loess seismic landslides.Based on high haiyuan earthquake intensity area as the research area,based on the haiyuan earthquake geological structure background,combining landslide visual interpretation,using statistical analysis,numerical simulation methods such as haiyuan earthquake landslide development are given,the haiyuan earthquake landslide development mechanism of an insight into the understanding of the quantitative,summarizes the characteristics of earthquake landslide,explain why the verified the haiyuan earthquake landslide concentrated development,quantitative assessment of landslide development factor.The kinematic characteristics of liquefied loess seismic landslides are presented and the distance prediction formula of liquefied loess seismic landslides is presented.The following achievements were obtained in this paper:(1)916 typical loess seismic landslides induced by haiyuan earthquake were determined by remote sensing interpretation method.According to the analysis,five development characteristics of haiyuan loess seismic landslide are determined.1)Upper plate distance effect.2)Slope direction effect.3)Geomorphologic microgeomorphologic effect.4)Area and volume effect.5)Movement liquefaction effect.(2)Through the comparison and summary of seismic landslides,fault activity characteristics and seismic force are still the primary key factors affecting the development of landslides,while morphological factors such as slope,elevation,area and volume have limited influence on the development of landslides.(3)Combined with the development characteristics of loess seismic landslides in Haiyuan,the development mechanism of loess seismic landslides in Xihaigu area is revealed.1)Through the numerical simulation of regional dynamic response,it is found that the seismic force plays a dominant role in the development of haiyuan seismic landslide,and the seismic acceleration and displacement in the Xihaigu area are at a high level.2)Using AHP quantitative evaluation,the weight of seismic acceleration was 0.522,playing the main control role;The weight of geomorphic type is 0.179,and the weight of geological condition is 0.1,which is also more important.(4)Based on the classification of loess seismic landslides,the kinematic characteristics of liquefied loess seismic landslides are determined as follows:1)The relation between the slope height and the slip distance of the landslide is H=0.096L.While H=0.122L can be approximately considered as the boundary between sliding type and liquefaction type landslide.2)The relationship between slip length and slip distance is L=1.97702L_1.3)The characteristic regression function of the original slope was L=0.18776?^3.10686.4)The characteristic regression function of landslide volume is L=0.18776?^3.10686.(5)4.According to the orthogonal test,the slope height has a significant influence on the landslide movement distance,the linear regression equation of significance factor:L=30.4+9.781H.Multiple nonlinear regression equation y=11.422+0.321x₁+8.231x₂+90.211(x₂/x₁)for the kinematic characteristics of liquefied loess.The above formulas can reflect the actual slip distance well.