Research On Dynamical Characteristics Of Historical Seismic Landslide On Huoluo Village Near Meigu River

Geo-hazards can induce significant disasters to daily lives,especially in China which has huge number of geo-hazards nationwide. It's extremely important to figure out the formation and mechanism of geo-hazards for the protection of human lives and property safety. Baesd on field investiments of geological tectonics and terrain, this paper analysised the development characteristics and genesis mechanism of Huoluo landslide by research on the landslide fractures and the rockmass structures. Further more, Geological structure concept model could be built for inversion analysis of Huoluo landslide by numerical simulation software(UDEC). And the results of simulation illustrated the formation process mechanism of H uoluo landslide, the induction factors of landslide and the critical dynamic strength were also be discussed.The main conclusions are shown belows:(1) Huoluo landslide is located in the Huoluowaxi Village with the right bank of Meigu River, Hagan countryside, Zhaojue County. The landslide consists of brittle block rockmass, the upper part is basalt and lower is limestone,carbonaceous shale weak zone of 3m at the root, below the landslide is shale clip siltstone. Landslide sliding toward the northeast and the maximum slip distance is 2km w hich is about 1.8 x 106m2 area, the original volume is estimated about 6 billion m3, landslide accumulation materials showed high speed remote debris flow which is commonly seen in earthquake landslides.(2) Landslide area is in the south of Daliangshan fault zone, the Anninghe-Zemuhe fault zone w hich has strong tectonics lies on the west,Mabian-Daguan fault zone lies on the northeast. Lianfeng fold break zone with weak activity feature lies on the south.The research area has such a strong tectonism which the basic seismic intensity is VII degree.Regional earthquake history has show n there are 21 of above or equal 6.0 magnitude earthquakes,but there are none above or equal 6.0 magnitude earthquakes around the research area.(3) The research area is located in the transitional zone of the Yunnan Guizhou Plateau and southwest Sichuan mountain, w hich "V", "U" type Valley can commonly observed, also with a wide range of weathering and unloading of rockmass, the terrain is usually steep; the hydroenergy here is abundant with so many rivers. The frequency of geo-hazards is high and geo-hazards arewidely distributed regionally.(4) The mechanical parameters of rockmass similar with Huoluo landslide can be concluded through engineering statistics.(5) Using the general discrete element software UDEC to simulate the process of landslide deformation and failure has show n that the landslides can be triggered by a=0.3g seismic acceleration. Through the monitoring data inside the slope, the dynamic response characteristics, forming process and mechanism of the landslide are discussed in details. The conclusion of landslide failure process can be drawn as :Shear failure by soft base?Sliding and dilatancy?Landslide failure?High speed debris flow.