首页|Mechanical behaviors of backfill-rock composites:Physical shear test and back-analysis
Mechanical behaviors of backfill-rock composites:Physical shear test and back-analysis
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
万方数据
The shear behavior of backfill-rock composites is crucial for mine safety and the management of surface subsidence.For exposing the shear failure mechanism of backfill-rock composites,we conducted shear tests on backfill-rock composites under three constant normal loads,compared with the unfilled rock.To investigate the macro-and meso-failure characteristics of the samples in the shear tests,the cracking behavior of samples was recorded by a high-speed camera and acoustic emission monitoring.In parallel with the experimental test,the numerical models of backfill-rock composites and unfilled rock were established using the discrete element method to analyze the continuous-discontinuous shearing pro-cess.Based on the damage mechanics and statistics,a novel shear constitutive model was proposed to describe mechanical behavior.The results show that backfill-rock composites had a special bimodal phenomenon of shearing load-deformation curve,i.e.the first shearing peak corresponded to rock break and the second shearing peak induced by the broken of aeolian sand-cement/fly ash paste backfill.Moreover,the shearing characteristic curves of the backfill-rock composites could be roughly divided into four stages,i.e.the shear failure of the specimens experienced:stage Ⅰ:stress concentration;stage Ⅱ:crack propagation;stage Ⅲ:crack coalescence;stage Ⅳ:shearing friction.The numerical simulation shows that the existence of aeolian sand-cement/fly ash paste backfill inevitably altered the coalescence type and failure mode of the specimens and had a strengthening effect on the shear strength of backfill-rock composites.Based on damage mechanics and statistics,a shear constitutive model was proposed to describe the shear fracture characteristics of specimens,especially the bimodal phenomenon.Finally,the micro-and meso-mechanisms of shear failure were discussed by combining the micro-test and nu-merical results.The research can advance the better understanding of the shear behavior of backfill-rock composites and contribute to the safety of mining engineering.
Physical simulationBackfill-rock compositesShear failureCrackingShear constitutive model
Jie Xin、Quan Jiang、Fengqiang Gong、Lang Liu、Chang Liu、Qiang Liu、Yao Yang、Pengfei Chen
展开 >
State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China
University of Chinese Academy of Sciences,Beijing,100049,China
School of Civil Engineering,Southeast University,Nanjing,211189,China
Energy School,Xi'an University of Science and Technology,Xi'an,710054,China
展开 >
National Natural Science Foundation of ChinaOpen Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chi
万方数据
