The Research On Deformation Mechanism And Reinforcement Method Of Cutting Slopes In Loose Accumulative Formation

With the rapid development of national highway, large amounts of cutting slope can't be inevitably produced.Due to rainfall or construction undeserved, the slope deformation and the landslide of geological hazards also happened very prominently.According to uncomplete count, in our country, every year the loss brought by geological hazards such as landslides is as high as 20 billion yuan, and 70 percent of geological hazards, such as landslide is related to rainfall.Therefore,the eaasy based on the background of zhuzhou yingbin cutting slope,through comprehensive engineering geology analysis about the landslide section, research the failure mode and deformation mechanism about the cutting slope of the loose accumulation layers, establish the generalized engineering geological model, using saturated and unsaturated seepage numerical simulation, under the condition of rainfall infiltration, study the stability of cutting slope of accumulative formation, and based on this, puts forward slope reinforcement method, made the following results:(1)Analyzes the cutting slope deformation mechanism and failure mode. The research shows that the deformation is shallow accmulative formation landslide, the main reason is because without retaining after slope excavation and the rainfall which produces stagnant water gathering on slope,caused airport traction collapse, eage ripping traction landslide, the failure mode is vermicular slippery - rip, sliding surface is the fourth department and strong weathering bedrock interface or loose body internal circular sliding.(2)The generalized loose accumulative formation engineering geological model is establish, we use saturated and unsaturated seepage finite element to simulate the high fill subgrade of transient seepage field when rainfall infiltrate, the calculated transient pore water pressure distribution will be used to limit equilibrium analysis of the slope, and consider the matrix suction influence on unsaturated soil shear strength. Explore rainfall intensity, duration impaction on slope stability.(3)Useing FLAC3D simulated deformation characteristics of slope excavation and different supporting method on slope, then evaluated the support effect on cutting slope, its results will bring the scientific basis to design of cutting slope protection.(4) Puts forward slope reinforcement method "reinforce foot and strong waist,cut slope and reduce load" design concept, through the research on landslide sliding mode and sliding surface depth, confirmed the landslide is shallow accumulative formation landslide, canceled the original design, instead frame beams anchor pile, Not only make the construction period more short,but also save more than 5 million yuan costs.