Study On Slope Stability Analysis Of Spoil Yard Based On Particle Flow Method

At present,with the expansion of the construction scale of highways,railways and other transportation projects,the amount of slag bodies caused by excavation is increasing,and the large amount accumulation of slag bodies brings great danger to people’s production and life.These relatively loose and non-uniform soil-rock mixture slag form the slag yard slope.When the accumulation height of these artificially accumulated slopes is too high and the slope is large,and it is subject to rainfall,stacking,etc.,the geological hazards such as debris flow and landslides bring people as much risk as natural slopes.The damage caused by the landslides in Shenzhen Guangming Abandoned Waste Land is a typical example.Therefore,it is of great practical engineering significance to study the sliding form of the landslide of the waste dump,analyze its landslide mechanism,and calculate its stability coefficient.Based on the field investigation of 56 waste dumps along the Guizhou route and taking the waste dump of K63+370 highway as an example,this paper applies a combination of on-site investigation,field test,indoor test and numerical simulation to investigate the possible landslide in the waste dump and analyze the destruction form and destruction mechanism.The research content mainly includes the following points:（1）Grasp the basic situation of the typical waste slag yard of K63+370 highway through field investigation,and sample for screening test to obtain the gradation curve characteristics of the waste slag body of the waste slag yard.The slag body is an earth-rock mixed waste slag mixed with silty clay and crushed stone soil.Through the indoor large-scale direct shear test,the shear strength value of the spoil body is obtained,the cohesive force value is 40k Pa,and the internal friction angle is 31.5°.Combined with 56 waste dumps in Guizhou,the common disaster forms of the waste dump were analyzed and the factors affecting the slope stability of the waste dump were summarized.（2）Using the PFC^2D particle flow parallel bonding model to conduct numerical simulation research on a typical waste slag yard,combined with the PFC^2D’s own biaxial test to establish the relationship between the mesoparameters of the particle flow and the macroscopic parameters,and obtain a complete set of mesomechanical parameters that suitable for the slag yard slope.（3）Use PFC^2D to construct a numerical model of K63+370 waste dump landslide particle flow and conduct stability evaluation to judge that the slope is in a stable state,combined with the strength reduction method to obtain a stability coefficient of 1.3,and simulate the process of instability and failure,Analyze the sliding forms at different time steps and the stress-strain characteristics of each monitoring point,and find that the slope of the waste slag yard will produce traction sliding after instability.（4）Combining the simulation results with the current status of the simulated waste dump,the traction landslide results for the top of the slope caused by the instability of the slope foot are given,and the disposal suggestions for protecting the slope foot of the waste dump are given,combined with the existence problems of 56 waste dumps in Guizhou Issues to put forward suggestions for the treatment of ordinary waste dumps.