Kinematic analysis of rock mass movement parameters in mining systems with caving

Abstract

The basic method of ground control in the mining systems with caving is overlying rock caving. The mining conditions of thick and gently dipping ore bodies with caving are reviewed as a case-study of Zapolyarny Mine. The research is grounded on the data of instrumental monitoring of overlying rock mass movement and on the detection results of the main jointing systems in the mine. The review of the instrumental monitoring data and the kinematic analysis allowed correlation of the existing jointing system parameters and the actual indicators of overlying rock mass movement. After generalization of all information, it is found that the movement mechanism is connected with displacements along the planes of steep-dip systems of joints (or with displacement of wedges formed when a number of joint systems intersect), and some blocks can even rotate in some areas. The latter takes place because of the concurrent displacements along the steep-dip and flat-dip systems of joints. Such movement behavior is confirmed by the instrumental monitoring data which show both sinking and upheaval of registration marks in some areas. The kinematic analysis results agree with the field observation data and can be used in learning neural networks to solve problems on determination of displacement angles. The results are also applicable in selecting directions for mining with caving with regard to the optimal conditions of roof caving at the minimized loading of the edge rock mass.