Research on layered evolution law of surrounding rock bearing layers and strength analysis of “layer-double arch” bearing structure
LI Yingming1，2，ZHAO Chengxing1，2，LIU Zenghui1，2，MENG Xiangrui1，2，PENG Rui3
(1. School of Mining and Safety Engineering，Anhui University of Science and Technology，Huainan，Anhui 232001，China；2. Key Laboratory of Safe and Effective Coal Mining of the Ministry of Education，Anhui University of Science and Technology，Huainan，Anhui 232001，China；3. School of Safety Engineering，North China Institute of Science and Technology，Beijing 101601，China)
Abstract：Taking a typical deep soft rock roadway of Xinhu coal mine as the engineering background，the bearing structure of the surrounding rock is divided into fluid，plastic softening，plastic hardening and elastic layers according to the variations of stress and strength of the surrounding rock，and the plastic softening and hardening layers form a plastic bearing zone. A dynamic reinforcement support scheme is proposed which includes the first support of anchor net spray and the second reinforcement of shallow and deep hole grouting jointed bolts and cables，and a mechanical model of the layer-double arch bearing structure is proposed in combination with the characteristics of the support scheme. Under the limit equilibrium condition，the forces acting at the layer-double arch bearing structure are analyzed and a formula for calculating the ultimate bearing strength is obtained. The engineering calculation shows that the ultimate bearing capacity of the air returning cross-cut of Xinhu coal mine reaches 29.30 MPa after the surrounding rock is reinforced by the proposed support scheme and that the support scheme is reliable. The on-site monitoring results show that，after the dynamic reinforcement support，the surrounding rock deformation of the roadway tends to be stable with only 36 mm of the subsidence of the roadway roof and 67 mm of the displacement of roadway's two side walls，and that the roadway can maintain long-term stability.
李英明1，2，赵呈星1，2，刘增辉1，2，孟祥瑞1，2，彭 瑞3. 围岩承载层分层演化规律及“层–双拱”承载结构强度分析[J]. 岩石力学与工程学报, 2020, 39(2): 217-227.
LI Yingming1，2，ZHAO Chengxing1，2，LIU Zenghui1，2，MENG Xiangrui1，2，PENG Rui3. Research on layered evolution law of surrounding rock bearing layers and strength analysis of “layer-double arch” bearing structure. , 2020, 39(2): 217-227.
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