Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5020206 | International Journal of Rock Mechanics and Mining Sciences | 2017 | 18 Pages |
Abstract
A thorough understanding of the deformation behavior, damage accumulation, and progressive failure of heterogeneous coal is a prerequisite for effective control of the surrounding rock and efficient exploitation of resources in underground coal mines. Such understanding can be obtained by analyzing both the macro- and meso-responses of coal to loading. Accordingly, a coupled macro- and meso-mechanical model for heterogeneous coal is developed and implemented in FLAC3D in the present study. The model is based on elasto-plastic mechanics and the energy dissipation and release principle, and heterogeneity is incorporated by the combination of a statistical approach and the discrete fracture network method. The model is calibrated by experimental data and is used to simulate stress-strain responses, the evolution of acoustic emission (AE) events, and energy conversion in compressed coal. The results reveal that: (1) the model can efficiently capture the dependency of the deformability, compressive strength and AE characteristics on the confining pressure; (2) the anisotropic behavior of heterogeneous coal is realistically realized, and the initiation, propagation and coalescence of micro-cracks can be located and tracked; and (3) stress paths, the degree of heterogeneity, and the unloading rate of confining pressure significantly influence the axial stress-strain response and AE event evolution in the stressed coal. The proposed model produces reasonable values for the roof weighting interval and expansion of the excavation-damaged zone around the gate when compared to the field data measured at the Dongzhouyao mine of China.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geotechnical Engineering and Engineering Geology
Authors
Jiachen Wang, Zhaohui Wang, Shengli Yang,