Study And Application On Regularity Of Mining Subsidence Of Deep And High Seam Strip Mining

With the increase of mining depth and mining thickness, there are many problems about surface movement and deformation regularity, size design and deformation prediction of strip mining. In view of the existing problems about study of deep and high seam strip mining, surface movement and deformation regularity of deep mining and the parameters of probability integral method are studied and obtained based on San He-jian coal mine. The influence factors of strip mining, the methods of mining size design and the regularity of mining subsidence of deep and high seam strip mining are analysed and studied, Then the mining size design and subsidence prediction are worked in view of east-2th mining area. The major work and conclusions of this dissertation as follow:(1) Through the analysis of measured data of railway observation station of east-4th mining area in San He-jian coal mine, surface movement and deformation regularity of deep mining, the final and small size working face prediction parameters of probability integral method are obtained. Through the modification of subsidence coefficient of small size working face, the subsidence coefficient of full mining is calculated. These conclusions provide basis for deep mining subsidence control and the choice of surface movement parameters of this region and similar conditions.(2) It is concluded that there is a great error in calculating parameters by commonly used formulas for parameters calculation, especially some parameters’ value is negative on deep strip mining(mining depth is more than 500m), and the formulas are not suitable for the application. When using the empirical formulas to calculate the prediction parameters, we should select the appropriate parameters according to the actual situation, in order to reduce the prediction error of the surface movement and deformation. Prediction models of GA-SVM and GA-GRNN are established by the Main Factors of Surface Subsidence of Strip Mining in view of the existing problems about parameters prediction of deep and high seam strip mining. Based on the comparison, we can select the appropriate prediction model to calculate the parameters and predict the surface deformation. And these provide the scientific basis for the engineering application of strip mining.(3) By analysing the main geological and mining factors of strip mining, with the geological conditions of San He-jian coal mine as the prototype to analyse mining depth, mining thickness, mining width, pillar width and the mining rate how to effect the surface movement and deformation of the deep and high seam strip mining by FLAC3 D, surface movement and deformation regularity of different conditions is obtained. According to the experimental data obtained by the different simulation schemes, the mathematical relationship between the maximum subsidence value, the maximum horizontal displacement value, the subsidence rate and the mining depth, mining thickness, mining width, pillar width is obtained by regression analysis. In order to protect the surface buildings, Surface Horizontal Deformation, the range of mining size and thickness of the regional geological and mining conditions should be determined based on the surface horizontal deformation value.(4) Taking an example of east-2th mining area, the reasonable mining sizes are obtained through the theoretical analysis and numerical simulation, and the prediction parameters are obtained and used to predict the surface deformation and orther works through the measured data and nonlinear theory, and the results provide the scientific basis for mining.