108 / 2023-05-30 20:19:11

Mining tremor analysis and prediction based on continuous subsidence observation

Mine earthquake,Mining earthquake prediction,Subsidence rate,Numerical simulation,Surface subsidence

Abstract: With the mining depth of the working face deepens the corresponding rock stress structural state exceeds the load limit that can be borne will lead to the top plate collapse caused by mining tremor damage to the ground surface will affect the mining efficiency and work safety. The analysis of surface deformation and subsidence caused by mining tremor will have a positive effect on the above problems. In order to study the influence of mining tremor on surface settlement during coal mining and to investigate the evolution of overburden damage induced by mining tremor at the working face, the trend of mining tremor occurrence in the working face mining process can be derived. The surface settlement changes were calculated based on the surface rock displacement and GNSS measured data of 63 upper 06 working face of Dongtan coal mine, and the geological model of the ore body was established by FLAC 3D software to simulate and calculate the displacement field and surface settlement of the surrounding rocks when the mining tremor occurred under deep mining conditions, and compared with the measured data to verify the analysis. The basic rules of surface movement with the mining face, the difference between numerical simulation and actual measurement during the occurrence of mining tremor, and the prediction basis of mining tremor with the settlement rate as the main feature were obtained. The results show that: the magnitude of the mining tremor is an important factor affecting the damage to the surface caused by the mining tremor, and the magnitude and the distribution of the earthquake source have different degrees of influence on the measured points; the settlement is greatest at the center of the working face strike line, and the center of the working face shows a symmetric settlement trend; the surface settlement fluctuates abnormally under the conditions of multiple mining tremor with the gradual expansion of the mining void area on the working face 63 upper 06; the segmental mining tremor at different monitoring times leads to the independence and commonality of the numerical simulation calculation results; the surface settlement calculated by numerical simulation and the surface settlement calculated by actual measurement data due to the breakage and moving of rock layers triggered by the mining tremor has a differential pattern;the moment of the mining tremor is near the peak of the subsidence rate at each GNSS monitoring point, and the peak may be advanced or delayed; the presence of one or more GNSS monitoring points with abnormal fluctuations in the average settlement rate within a short period of time and often reaching more than 100%, there is a possibility that a mine tremor may occur within a short period of time. The results of the study can provide implications for future mining work at the working face.