Yushu "4.14" Earthquake Secondary Geological Disasters In The Development And Distribution Characteristics

Yushu "4.14" earthquake triggered massive geohazards like landslide, collapse, debrisflow and lots of hidden troubles. These situations pose a huge threat to the post-earthquakereconstruction, and the residents and property safety. In this paper, based on lots of fieldinvestigation on the earthquake in Yushu area, combining to indoor comprehensive analysis,we made a systematic research on type, development characteristics and distributionregularities of the earthquake secondary geological disasters in Yushu area. The resultsshow that: the post-earthquake induced secondary geological disasters increased to6timescompared to the number before the earthquake, and the distribution scope was enlarged, lotsof local area concentrated development, the number of large and super large geologicaldisasters was increased. Earthquake induced landslide has its features, low landslide is moreprominent, soil slippery phenomenon is widespread, and landslide has the characteristics ofseismic liquefaction; earthquake triggered collapses has the features of high clusters andlarge stones rolling with high speed; Post-earthquake debris flow also has its developmentcharacteristics, mainly respected by dramatically increase of source amount andsusceptibility; the main deformation mode of earthquake induced slope instability isslipping-cracking mode and shattering–dumping-cracking mode. Distributions of Yushu“4.14” earthquake secondary geological disasters are closely related with the topography,geological structure, human engineering and economic activities. The topography andgeological structure play a leading role of the earthquake secondary geological disastersdevelopment play. By selecting and analyzing the typical cases like Jiegu Temple landslideand collapse, Mengzong Valley debris flow in research area, we know that the earthquakeexacerbated the deformation trend of landslide and collapse, so this area was not in a stablestatus; and earthquake also increased the source amount of debris follow, frequency ofoccurrence will be greatly improved, a comprehensive geological hazard managementengineering need to be carried out.