Mining Subsidence Prediction And Visualization Of Thick Unconsolidated Layer In Northwest Mining Areas

Mining subsidence prediction is one of the core contents in mining subsidence subject. Northwest area of China which is covered by loess layer is an important coal production base. As the topography is complex and the thickness of loess layer is great, overburden failure and surface movement caused by underground mining has particularity. Studying prediction theory in thick unconsolidated layer covered mining areas, establishing specific theoretical model of surface movement, and developing the software have great significance to study mining subsidence and its protection.Based on mining subsidence model in thick unconsolidated layer covered mining areas, the prediction program of mining subsidence is developed by use of C# programming language. Meanwhile, visualization of prediction results is implemented. The main findings of this paper are shown as follows:(1) Aiming at the double mediums mining subsidence model in thick loess layer covered mining areas, probability integration prediction model for double mediums is derived by using basic ideas of stochastic medium theory. New prediction model overcomes the uncertainty of selecting prediction parameters and makes the prediction results become more close to actual because overlying strata is decomposed into two mediums which are loess layer and bedrock in the new model. The model is expected to extend the application region of stochastic medium theory in the prediction of mining subsidence in western mining areas and has practical values.(2) Based on C# programming language, program implementation of mining subsidence prediction model in thick unconsolidated layer covered mining areas is implemented by using Visual Studio 2005. Surface subsidence values, inclination values, curvature values, horizontal movement values and horizontal deformation values of approximate horizontal coal seam or medial tipping coal seam can be predicted and calculated by using this computer program. Meanwhile, surface displacement and deformation values of any points in mining subsidence basin can be calculated by this program.(3) Based on C # language and combined with open source control ZedGraph, curve drawing of surface displacement and deformation is implemented. Prediction curves of various deformation values on the main section can be outputted. Meanwhile, contours of surface displacement and deformation in mining subsidence basin can be drawn. Three-dimensional display of surface displacement and deformation is implemented by using graphics interface of OpenGL.(4) 40301 working face of Big Temple coal mine in Bingchang mining area is selected as example for this study. Surface movement and deformation of this working face is predicted by using the computer program. Through the comparison between the prediction results and observation results of 40301 working face, it is confirmed that the computational accuracy of program is in the allowable scope and can meet the application requirements.The results of this research provide a new technology method and strong information support for accurate prdicction of mining subsidence and surface protection in Northwest mining areas.