Accumulated Deformation Characteristics Of Coal Gangue Subgrade Filler Under Cyclic Load

Coal gangue is a kind of waste rock,which is generally produced in the process of coal mine construction,coal mining and processing.In recent years,the use of coal resources has greatly increased.The large-scale mining and use of coal resources has not only caused serious pollution to the environment,but also has hidden safety hazards in the stacking of wastes.Therefore,how to effectively comprehensively utilize coal gangue is an urgent research topic in mines.At present,the comprehensive utilization of coal gangue mainly includes two ways,one is to recover coal gangue as a kind of surplus resource,and the other is to use engineering.In engineering utilization,coal gangue is generally used as roadbed filler.As a roadbed filler,coal gangue has high density,high strength,high bearing capacity,high structural stability,excellent water permeability,and is not easy to deform.Therefore,it is widely used in railways,highways,and embankments.There are many civil engineering fields,but there are few studies on the cumulative deformation of coal gangue,so this article mainly focuses on the cumulative deformation characteristics of coal gangue as roadbed filler.This paper takes coal gangue from Tangjiashan Coal Mine in Xiangtan as the research object,based on indoor tests,through a series of indoor physical tests and large-scale dynamic triaxial tests on coal gangue,focusing on the study of coal gangue under different confining pressures and different cyclic stress ratios.,The dynamic characteristics and cumulative deformation characteristics of coal gangue,and further exploration of coal gangue roadbed filling under the action of large cycles of cyclic loading,through the establishment of a cumulative deformation model,and comparison and analysis with other models,and then a large number of tests to verify the model Accuracy.The study found that the dynamic stress-dynamic strain relationship curve of the coal gangue sample is close to a hyperbola,showing a hysteretic loop shape,which shows the nonlinear characteristics and hysteresis of coarse-grained soil;at low vibration orders,when the dynamic strain is small,The hysteretic loop is a closed ellipse,indicating the viscoelastic properties of coarse-grained soil;under high vibration times,when the dynamic strain is large,the hysteretic loop curve will no longer be closed,the opening will become larger,and plastic deformation will occur.Through the analysis of the coal gangue test data,the hyperbolic model considering the influence of the cyclic stress ratio and the power function cumulative calculation model simplified by Liu Bao,and the original data were fitted,and the fitting effect was good.