Triggering types, characteristics and disaster mechanism of seismic loess landslides
摘要
Based on the field investigation and exploration, unmanned aerial survey and large-scale shaking table tests, the triggering types, characteristics and disaster-generating mechanism of seismic loess landslides are systematically studied. The results show that the earthquake-induced loess landslides have their distinctive characteristics in spatial distribution, single size, influencing area, plane modality, topographical and hydrological conditions, seismic intensity, deposit thickness and relations to seismic faults. They can be classified into three types from the perspective of the triggering mechanism: shear landslides, liquefaction landslides and seismic subsidence landslides. The shear landslides can be further classified according to the lithology of the sliding surface strata into three types: landslides within a loess layer, landslides on the contact surface between loess and mudstone, and landslides cutting into bedrock. The liquefaction landslides can be divided according to the location of the liquefaction layer into three types: deep liquefaction sliding type, surface liquefaction mudflow, and combined deep-surface liquefaction type. The seismic subsidence landslides can be divided into two types of landslides, subsidence slide and avalanche slide, according to the damage modes caused by seismic subsidence. This study may provide a scientific basis for the risk assessment, prevention and control of loess seismic landslides.