Numerical modelling of anomalous microseismicity influenced by lithological heterogeneity in longwall top coal caving mining
| Autor: | Sevket Durucan, Sergej Jamnikar, Ji-Quan Shi, Wenzhuo Cao, Anna Korre |
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| Přispěvatelé: | Commission of the European Communities |
| Rok vydání: | 2019 |
| Předmět: |
Technology
Energy & Fuels 020209 energy Stratigraphy ZONE 02 engineering and technology Slip (materials science) Induced seismicity 010502 geochemistry & geophysics 01 natural sciences Power law Longwall coal mining Mining engineering 0202 electrical engineering electronic engineering information engineering Coal Geosciences Multidisciplinary Scaling 0105 earth and related environmental sciences Microseism Science & Technology Energy business.industry Discrete fracture network (DFN) Seismic modelling Coal mining Geology 0914 Resources Engineering and Extractive Metallurgy Strength of materials Microseismicity FRACTURE Fuel Technology 0403 Geology Physical Sciences INDUCED SEISMICITY Economic Geology Heterogeneity business 0406 Physical Geography and Environmental Geoscience |
| Popis: | Mining-induced microseismicity has been extensively used to evaluate the potential for rock bursts and coal and gas outbursts in underground coal mines. In a research project completed a few years ago, it was observed that characteristics of microseismicity around a working longwall panel were fairly consistent over the monitoring period until a lithological heterogeneity zone with a relatively high coal strength was reached. The current research presented in this paper aims at achieving a better understanding of the effect of lithological heterogeneity on microseismic activity in longwall coal mining. The heterogeneous zone inferred from the tomography measurements was first digitalised and implemented into a 3D geomechanical model. A microseismicity modelling approach which combines deterministic stress and failure analysis together with a stochastic fracture slip evaluation was used to simulate the evolution of microseismicity induced by the progressive face advance passing through the heterogeneous zone. The heterogeneity was taken into account by varying the material strength and the fracture attributes of the elements within the high strength zone. Results have shown that both the high rock strength of coal lithotype and low power law scaling exponent of fractures within this zone contribute to the reduction in fitted b values from frequency-magnitude distribution of microseismicity and the increase in fitted Gaussian distribution parameters to the logarithmic event energy. These deviations are believed to result from the combined effects of increased stress drops and slipped fracture sizes when the heterogeneous zone is approached. |
| Databáze: | OpenAIRE |
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