Experimental Studies On Sliding And Scattering Characteristics Of Coarse-Aggregate Soil Mass And Blocking Measures Of Sliding Soil Mass

The debris flow is a kind of geological disasterwith great hazards,and it is currently unable to make effective predictions.Research on the characteristics of its motion,the extent of damage and the adoption of effective protection measures has been a topic of concern for scholars.In this paper,the indoor physical model test of coarse particles along the ramp for cohesionless landslide,the spread and accumulation of the entire movement.The influences of the initial deposition state,particle size,slope angle,and other factors on the final accumulation parameters(stroke,maximum stacking thickness,and position)of the landslide movement were analyzed.At the same time,analyzes the effects of coarse,fine two kinds of particles of different levels of accumulation of the final stacked body and the accumulation of state.Particularly,it is observed that the final distributions of soil mass are hardly affected by the initial state of soil mass;The inclination angle of the chute has a great influence on the relative position of the maximum thickness of the soil mass,and their relationship can be determined by a fitting formula;When the inclination angle of chute is small,the particle size has a greater effect on the rear of the soil mass and has a less effect on the front of the soil mass,while it is opposite when the inclination is large.Further study on landslides and mitigations based on the pile-retaining test is conducted to study the sheltering effect of retaining piles on sliding coarse-grained cohesive-free soil.Exploration of the pile spacing block,the number of layers and the pile stop block pile distance from the chute mouth of the masking effect of different particle size of the stacked body.The results of laboratory tests show that,the accumulation length of the pile increases with the increase of particle size and the maximum accumulation width first decreases and then increases with the increase of particle sizeand there "bottleneck phenomenon".The pile has a significant effect on reducing the accumulation range and the smaller the particle size is,the more obvious it is.The content of occlusion body decreases with the increase of L/D ratio of gear pile to slot mouth.With the increase of(S/D)Value decreases.In addition to the above laboratory tests,This paper is also based on the discrete element method particle flow code(PFC),to prepare the numerical simulation program for the collapsing and sliding motion of the coarse-grained soil.Based on the results of routine triaxial tests in the laboratory,the relationship between microscopic parameters and macroscopic parameters was determined.Based on the calibration parameters usingPFC for numerical simulation study,the numerical simulation results obtained are basically consistent with the test results.At the same time,several numerical simulations were performed based on the PFC program and some valuable conclusions were drawn,Further reduce the spacing of retaining piles so that S/D = 3.5,the results show that the content of the denser shielding particles in the retaining pile arrangement does not increase significantly.When the S/D reaches a certain value,it not only meets the economic effect,but also can play the role of shielding.When the L/D is reduced to 3.5,the content of the accumulation body in the area 1 decreases smoothly as the L/D increases first and then decreases sharply.Numerical results show that the best shielding effect is achieved when L/D and S/D reach a certain value.The rows and piles of plum blossom and rectangle distribution are almost the same.