Study Of Failure Mechanism Of Granular Soil Slopes And Soil Nail Reinforcement Technique

Through the analysis of slope failure mechanisms and actual research of soil nailing techniques, concerning understanding on slope failure mechanisms has been widely studied, but there are only a very few of the studies really involved the failure mechanism of granular soil slope. Moreover, although effects of soil nail inclination on reinforcement has been considered and discussed by many scholars, most of studies have just overlooked the relationship between soil failure mechanisms and mechanism of soil nail, failed to point out the installing optimum angle of soil nails. This paper, which presents the research method of performing laboratory experiments combined with numerical simulation, focuses primarily on dealing with granular slope failure mechanisms and soil nail inclination problems.Firstly, through the aluminum rods model experiments and the numerical simulation by distinct element method, the failure mechanism of granular soil slope in dry and wet states is studied. After that, on this basis, a comparison, in order to find out the more effective method, is made between the installing soil nails along the direction perpendicular to the slope surface and that in the direction of the minor principal stress 03.Then, to better simulate the granular soil failure process, the experiments were carried out with natural river sand samples in both dry and wet states. Through observing the slope failure shape and measuring the slope failure angle, displacement vector of soil, the failure mechanism of slopes and the effect of installing angle of soil nails on the slope stability were investigated. Meanwhile, these tests also show that the efficiency of soil nail reinforcement is influenced not only by soil nail inclination but also by the distance between soil nails and by its length.Finally, the plane finite element method was used to analyze granular soil slopes. Then, computed results will be compared with the test results to verify the feasibility of FEM. In addition, the direction of the principal stress of soil and the distribution law of the axial force of soil nails were analyzed, and it explains further that the changes of setting angle of soil nails effect slope reinforcement.