Movement Mechanism Of Permafrost Landslide Based On GPS And Resistivity Surveying

Landslide is a downward movement along the slope at the landslide surface of soil, rock or a mixture of both. Of most countries in the world are subject to different degrees of threat of landslides, landslide is so vast and diverse area, and it is because of a variety of landslide mechanism. Atmospheric precipitation, earthquakes, volcanoes, wildfires, rapid snow melting as well as other factors may be induced by main reason for it, especially in the last, some risk of human engineering activities have also become the primary cause of the landslide. In the Heilongjiang province of china, as the construction of high-grade road and the railway crossing permafrost regions, due to melting of frozen soil, there is More and more ground instability problem, research on frozen soil problems become to a hot spot. Because of the special nature of climate conditions, formation mechanism and sliding characteristics of landslides in the area has a certain degree of particularity.The paper is based on transportation project of science and technology in Heilongjiang province "landslide section in permafrost melt and extension project for widening subgrade stability technology of Expressway", the study of vector is the highway expansion project of Beian to Heihe Expressway, a trial section of subgrade and foundation soil for research. Study area located in Lesser Khingan Range central region, in the high latitude permafrost degradation of China. Spring warms fast and shortly, summer is hot and rainy, autumn cools fast and shortly, winter is cold and long. the annual average temperature is-0.8℃. The average annual precipitation is510～572mm, rainfall concentrate in July to September, account for about60%of annual total precipitation. Maximum seasonal frozen depth is2.30-2.50m, freeze injury is prevalent, there is island permafrost distributed in cleugh. Special shape topography, active groundwater, intense freeze-thaw erosion and human engineering activities are material conditions and power factor of the landslide.Combining with GPS positioning technology and high-density resistivity method, researching on movement mechanism of landslide in K178+530section of Bei’an-Heihe Expressway to analyse landslide body dynamic characteristics variation of surface morphology and internal soil mass. In order to obtain lithology and geological structure of landslide section, we did drilling exploration, and four drilling holes were arranged in the area. We arranged nearly49GPS gauge piles at different positions on the landslide on September13,2010, using GPS to monitor the moving data of these gauge piles (monitoring cycle is more than one year), accurately grasp the directions and rates of movement at various locations at different times of the landslide. At the same time, we used the high-density resistivity method to detect the resistivity of the landslide several times, obtaining resistivity changes of the landslide of different locations, different time, then comprehensively analysising the variation characteristics of resistivity value and delay characteristics of landslide.