Simulation studies on stress field evolution of roadway excavation under different confining pressures
Author(s): LIN Jian, WANG Yang, YANG Jing-he, WANG Zheng-sheng, CAI Jia-fang, Coal Mining and Designing Department, Tiandi Science and Technology Co., Ltd., Coal Mining and Designing Branch, China Coal Research Institute
Pages: 2313-2319
Year: 2015 Issue: 10
Journal: Journal of China Coal Society
Keyword: roadway; excavating; stress fields; evolution;
Abstract: A model of mine roadway was constrained on the boundary by home-made mold,loaded by microcomputer control electro-hydraulic servo universal testing machine in laboratory.Thus the coal mime roadway excavation was simulated by unloading the front constraint plate of model.The variation characteristics of axial stress before and after the excavation of coal seam with different stresses were obtained,and also the roadway surrounding rock stress field variation characteristics before and after excavation under low,secondary and high stress conditions were discussed.The results showed that the tensile stress area near the excavation plane was formed under low stress condition,but the internal stress values were small,the whole surrounding rock was in elastic state,the resistance ability of surrounding rock to excavation disturbance was strong.Under the condition of secondary stress,the tensile stress area of surrounding rock in the shallow further expanded,which was caused by model excavation,rock mass reached yield status and the excavation disturbance of surrounding rock was strong,the stress field after excavation began to present ‘pull-pressurepull’alternate phenomenon. Under the high stress condition,the surrounding rock obviously appeared as plastic and the rock mass within the model all appeared in a state of tension.By excavation disturbance,the surrounding rock sur-face rapid returned to compression state and moved to deep again,forming obvious ‘pull-pressure-pull-pressure’dynamic alternation phenomenon,damage depth of surrounding rock was larger,the ability to resist disturbance was poor,appeared deep mining characteristics.
Pages: 2313-2319
Year: 2015 Issue: 10
Journal: Journal of China Coal Society
Keyword: roadway; excavating; stress fields; evolution;
Abstract: A model of mine roadway was constrained on the boundary by home-made mold,loaded by microcomputer control electro-hydraulic servo universal testing machine in laboratory.Thus the coal mime roadway excavation was simulated by unloading the front constraint plate of model.The variation characteristics of axial stress before and after the excavation of coal seam with different stresses were obtained,and also the roadway surrounding rock stress field variation characteristics before and after excavation under low,secondary and high stress conditions were discussed.The results showed that the tensile stress area near the excavation plane was formed under low stress condition,but the internal stress values were small,the whole surrounding rock was in elastic state,the resistance ability of surrounding rock to excavation disturbance was strong.Under the condition of secondary stress,the tensile stress area of surrounding rock in the shallow further expanded,which was caused by model excavation,rock mass reached yield status and the excavation disturbance of surrounding rock was strong,the stress field after excavation began to present ‘pull-pressurepull’alternate phenomenon. Under the high stress condition,the surrounding rock obviously appeared as plastic and the rock mass within the model all appeared in a state of tension.By excavation disturbance,the surrounding rock sur-face rapid returned to compression state and moved to deep again,forming obvious ‘pull-pressure-pull-pressure’dynamic alternation phenomenon,damage depth of surrounding rock was larger,the ability to resist disturbance was poor,appeared deep mining characteristics.
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