Design And Development Of Goaf Subsidence Prediction System Based On GIS

China is a large consumer of coal resources as well as a large country of raw coal mining,mining areas throughout the country.Since the end of the 20 th century,the mining order in our country is relatively chaotic.Illegal and disorderly indiscriminate mining left a large number of goaf around the mines.On the other hand,our land resources are increasingly scarce,many infrastructure such as civil buildings,roads and channels have to cross the mine.The existence of these goaf has great influence on the surface stability.They are prone to formation cracks,subsidence and collapse,causing major natural disasters such as debris flow,damaging the local ecological environment,and thus threatening the safety of people and property.Therefore,it's very necessary to scientifically and effectively manage the subsidence data and make subsidence prediction for the goaf.With the help of Visual Studio 2010 development environment and Access database,this paper adopts object-oriented C# programming language and HotMapGIS as platform,which realizes the development of " design and development of goaf subsidence prediction system based on GIS ".The paper mainly achieve the following work:(1)According to the measured data and geological and topographic data of the Guocun coal mine,the database in combination with the data requirements of probability integral method is set up.It realizes the informatization management of monitoring points and prediction parameters,and provides a basis for sharing the data among subsystems.(2)Guided by the basic idea of three-dimensional modeling of goaf,the extracted inflexion coordinates are divided into boundary constraints to construct the solid model of goaf.(3)The prediction model of surface movement and deformation is established based on the probabilistic integral method,and the idea of maximum prediction method is expounded.Combined with the "three conditions"(under buildings,water bodies and railways)coal mining regulations,the method to obtain the prediction parameters under different known conditions is determined.This paper gives a method of polygon equidistance scaling to eliminate the influence of inflection point offset in the calculation process.The modeling method of grey prediction theory and the precision evaluation method of the model is introduced,so as to build a prediction system which integrates the prediction of goaf deformation limit value and process prediction,and meet the demand of the prediction results in different engineering stages.(4)The predicted results are analyzed and processed,and then they will be expressed visually in the form of contour.Moreover,the predicted subsidence value is vector superimposed with the ground Z coordinate of the inflection point obtained by the interpolation of borehole data,and the DEM of the surface before and after subsidence are compared.The whole system realizes the internal transmission and visual expression of the data.The predicted results conform to the theory of moving deformation and the system is feasible.