Ren Heng, Zhu Yongjian, Yao Qi, Li Peng, Wei Mingxing
School of Civil Engineering, Hunan City University, Yiyang, 413000, China.
College of Resources, Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
Sci Rep. 2025 Aug 2;15(1):28256. doi: 10.1038/s41598-025-13442-0.
In view of the difficulty of rock mass crushing and support on the surface of deep soft rock roadway with high stress, RMT-150 C rock mechanics experiment system was used to carry out the orthogonal test for sensitivity analysis of rock bolt support parameters of cemented broken rock mass. Through numerical simulation, the relationship between bolt parameters and the form and range of the formed compressive stress field was studied. The evolution law of interfacial shear stress in the anchorage section at the stage of elastic deformation is obtained. The results show that the main factors affecting the compressive strength of anchor solid are the number of anchor rods per unit area, followed by the presence or absence of anchor net, the anchor depth ratio, and the diameter of anchor rods. Increasing the anchorage length and diameter of the bolt is beneficial to improving the shear strength reserve of the bolt; The length of bolt affects the superposition range of axial compressive stress zone, the spacing of bolt affects the superposition range of radial compressive stress zone, and the diameter of bolt has little effect on the superposition range of compressive stress zone. The longer the length of bolt and the larger the spacing, the smaller the superposition range of compressive stress zone, or even disappear. The prestressing of bolt can make up for the supporting defects caused by long length and large spacing. The larger the prestressing is, the shape of compressive stress zone changes from "peanut shape" to "pomegranate shape", and the active supporting effect becomes better gradually. The research results have reference significance for the selection of engineering bolt supporting parameters.
针对深部高应力软岩巷道围岩破碎及支护困难的问题，采用RMT - 150C岩石力学试验系统对胶结破碎岩体锚杆支护参数进行敏感性正交试验分析。通过数值模拟，研究了锚杆参数与形成的压应力场形态及范围之间的关系，得出了弹性变形阶段锚固段界面剪应力的演化规律。结果表明，影响锚固实体抗压强度的主要因素是单位面积锚杆根数，其次是有无锚网、锚杆深度比及锚杆直径。增加锚杆锚固长度和直径有利于提高锚杆抗剪强度储备；锚杆长度影响轴向压应力区叠加范围，锚杆间距影响径向压应力区叠加范围，锚杆直径对压应力区叠加范围影响较小。锚杆长度越长、间距越大，压应力区叠加范围越小，甚至消失。锚杆预应力可弥补长锚杆、大间距造成的支护缺陷，预应力越大，压应力区形态由“花生形”向“石榴形”转变，主动支护效果逐渐变好。研究成果对工程锚杆支护参数的选取具有参考意义。
