Bei’an-Heihe Expressway K177+550Landslide Section Of Experimental Study Of Soil Physical And Mechanical Indexes

Landslide is a kind of common natural disaster, mountain is one of serious problems affecting the safety of mountain area highway transportation, in all of geological disasters affecting the safety of road transport, the harm of the landslide is serious and more common. Following the rapid development of high-grade highway construction in China, to be built or under construction of highway will through the regional adverse geological conditions, the harm of the landslide on the highway is also increasingly clear. Landslide occurrence area with the texture of the condition and the natural environment has a direct connection, the mechanism of landslides are common, also has the particularity of different. China’s Heilongjiang province in northern area of Lesser Khingan Range, has low hilly landform, continental monsoon climate, the islands belong to the frozen soil degradation region, the region of ancient landslides landform, landslide are numerous, forms and formation mechanism has a distinct regional characteristic. Landslides in the area of research is very important to ensure road safety and long-term stability. At present, the research of landslide disasters in this region and practice are relatively less.The cause of the landslide mainly depends on the change of the internal stress state and strength of soil slope, from the graces, study on landslide mechanism, is the study of landslide soil mass deformation and failure mechanism. In this paper, relying on the heilongjiang province transportation hall of science and technology project "melting permafrost and landslides road subgrade stability technology widen the highway expansion project research", jilin to soon to heihe heihe river highway section of the highway expansion project as the research carrier, north of the black expressway K177+550landslide sections as the research object. Through reading and analyzing research on landslide field exploration and indoor soil test results, the preliminary master the research situation at home and abroad and the research methods of landslide, for the object of study made a concrete research plan. Using GPS surveying and mapping technology to the landslide area topography measurement, topographic map and map the region, to master the research area of landform; In landslide areas around borehole layout and landslide monitoring instrument, to grasp the changes among soil physical indicators of the landslide characteristics and movement regularity of landslides. Drilling was carried out on the landslide survey, in order to grasp the landslide geological structure and lithologic layers; Of landslide soil drilling sampling of each structure, through the field experiment with landslide basic physical test index of each soil layer, through the indoor test for various structural layers in the landslide, the change characteristics of soil physics, mechanics, etc were studied. The main results are as follows: (1) through the indoor experiment to test the basic test indexes of landslide soil layers, particle composition, consistency index, study landslide in each soil layer structure, are fine grained soils, except sandstone grain size composition is missing, grading is bad; Sliding body and sliding bed boundary of soil water content were similar, the plastic area is bigger, plastic range small, sliding zone reflects the structure of the differences in soil water stability;(2) the various structural layers in the indoor test of landslide, the saturated permeability coefficient of soil, soil based on the matrix suction in unsaturated state measurements, the moisture content of soil under unsaturated condition is derived with the theory of permeability coefficient curve; Results show that the permeability coefficient of sliding bed and other structural layer vary widely, and is the difference between soil permeability coefficient on slope stability influence gives theoretical explanation;(3) respectively using automatic triaxial apparatus to test the soil of the landslide mass and slide zone and slide bed soil under different moisture content of the elastic modulus, elastic modulus under different attached load, and analyzed the change rule; Results show that the elastic modulus of the soil in plastic for maximum moisture content near some point, a linear change, soil elastic modulus increases with additional load is reduced;(4) through laboratory direct shear and repeated direct shear test, get landslide under different moisture content in each layer of soil shear strength indexes, and analyzes the change point. Based on test results, do to K177+550landslide stability calculation.Through the above research, the preliminary reveals the north black expressway K177+550landslide of soil physical and mechanical indexes variation characteristics and formation mechanism of landslide and improve the region’s rich landslide research and analysis of this type of landslide in the region and the prevention and control work to provide the reference and basis.