Study On The Characteristics Of Land Collapse And Failure Law Of Overlying Strata In Coal Face Of Huangling Mining Area

Huangling mining area lies in the east part of Huanglong Jurassic coalfield, and it is abundant in coal resources. After excavating the coal seam from underground, land resources, water resources, building, ecological environment, and transportation would be destroyed seriously. So study the characteristics and failure law of overlying strata is important to the safe of mine, land resources, water resources, buildings, ecological environment and Government's Policy-Making in Huangling mining area.Based on the survey and analyse of the land collapse (discontinuous deformation), there are 2 land collapse types that are collapse basin and collapse slot are summarized. The paper conclude that main factors influenced the land collapse (discontinuous deformation) are the mining depth and the thickness of bedrock, the width of working face and the mining height, overlying rock and the thickness of key strata and landform et al.This paper using formulas from the regulations (Regulations for setting coal pillar and mining under buildings, water bodies, railways and main roadways) and norms (National Exploration norms for hydrogeology and engineering geology of coal mine), numerical simulation, empirical data, and the measured data to analyze the development law for "two zones" of overburden rock in Huangling mining area. The ratio calculated by formulas of regulations and norms is less than measured value;the data obtained by numerical simulation and experience are close to the measured value, the ratio range from 25.2 to 27.5. After comprehensive analyzing, it is feasible to predict the development height for "two zones" of overburden rock in Huangling mining area using the ratio 28.Then based on the analysis above, water-disaster prediction figure in Huangling second mine first mining area is made and the most area fall into low danger area and northeast of the first mining area belong to medium danger area. Through numerical simulation, and field survey and analysis, it summarize the model of overlying strata failure with the land collapse (discontinuous deformation) developed in Huangling mining area, which is cavied zone, fractured zone, continuous deformation zone( the local tensile failure areas of the key strata, and the failure of the loose strata). There are not free space between continuous deformation zone and fractured zone. The local tensile failure area of the key strata is only the weakening of rockmass strength.