Study On The Influence Of Mining Subsidence On The Key Physical Properties Of Soil

Underground subsidence caused by underground coal mining affects the physical properties of surface soil directly,causing disturbances of surface animal and plant habitats,exacerbating soil erosion,and causing deterioration of the ecological environment.Shendong Mining Area belongs to the loess-desert transition zone,which has the characteristics of high underground coal mining intensity and fragile ecological environment.and the physical properties of the surface soil have particularity.The research on the effect of mining subsidence on the key physical properties of surface soil in this area has important practical significance for the ecological environment protection and treatment.At present,the conventional research methods are generally carry out researches on the change rules of the key physical properties of the soil caused by surface subsidence and deformation through field tests,remote sensing,on-site sampling and indoor determination.However,due to the complexity of the field and the strong heterogeneity of the soil space,it is impossible to exclude the interference of other factors,so it is difficult to accurately study the influence rule of the surface subsidence deformation on the key physical properties of the soil.Through situ monitoring of the key physical properties of soil,monitoring of soil deformation and monitoring of soil moisture in the vicinity of cracks,this paper shows that the mining subsidence has an influence on the key physical properties of soil,but the law of influence is not obvious.And then,this paper conducted the study,using laboratory test to control soil compression,tensile deformation process and deformation quantity.by measuring and analyzing the soil bulk density,specific gravity,pore ratio,infiltration rate,evaporation rate and water characteristic curve based on the moving deformation process and final state of surface soil.Through the analysis of indoor soil test results of soil physical properties and deformation of the key field verification results,it is found that the subsidence basin subsidence on soil physical properties of compression key has significant effect of mining,significantly increased soil bulk density and soil deformation,significantly reduced the soil pore ratio,infiltration rate and evaporation rate.At the same time,soil compression has a significant influence on soil water characteristic curve,which significantly increase soil water holding capacity.The tensile deformation limit of the soil in the study area is very small,and the deformation amount is 0.08% when the fracture is broken,so it has no significant influence on the soil key physical properties.The spatial heterogeneity of soil in this area is strong,especially in different slope positions.But the general law of the influence of mining subsidence on the key physical properties of soil is basically the same.The physical properties of the soil are affected more significantly by the mining subsidence in the middle,the top weaker and the bottom weakest among the slope.