Subsidence engineering comprehension is crucial if planners and designers are to develop effective measures to prevent, minimize and or remedy subsidence effects. Subsidence and its components, tilt and strain, have disastrous effects on structures, human life and mining operations economics among other effects if not adequately tamed. This paper utilizes survey monitoring pre and post mining field observations to evaluate coal mining induced surface subsidence. Several issues concerning subsidence due to underground mining are discussed presenting an opportunity to share insights on this subject, which affect underground coal mines. Some of the issues covered include subsidence due to different types of mining, characteristics of subsidence, prediction of subsidence, monitoring and management of subsidence, effects of subsidence and control of mining-induced subsidence effects. The survey monitoring data was processed by the author and the results are presented in this paper in form graphical presentations derived from tables of calculations. The graphs of subsidence profile, tilt profile and major and minor principal strains profiles are also provided. The interpretations and comments about any anomalies are also provided thereof.
A clear understanding of subsidence and its mechanisms is crucial if one is to design an underground mining operation that presents minimal effects of subsidence. If not appropriately designed for, subsidence can cause disastrous effects on linear, tower, block and agricultural structures, dealing a severe blow on the economics of the mining operation. Technical approaches and statutes have been developed in order to contain subsidence to a sustainable level and hence afford a profitable business venture. This paper uses survey monitoring data to evaluate surface subsidence due to underground coal mining. The survey monitored data consist of two lines before and after mining. The observations lines were along the long axis of the panel. Each line had 65 points and the x, y and z readings were recorded before and after mining situations. The edges of the evaluated panel occurred at approximately 70 m and 250 m, see Figure 1. The mining depth is 127 m, mining height 4 m and panel width is 130m. The mining method used is pillar extraction. Graphs illustrating the Major InducedTilt and the Principal Strains are presented in the paper and any noticed anomalies in the subsidence are commented on. Some of the issues discussed in this paper include subsidence due to different types of mining, characteristics of subsidence, prediction of subsidence, monitoring and management of subsidence, effects of subsidence and control of mining-induced subsidence effects.
