深井软岩巷道温压耦合作用下锚固体破坏机理及应用研究

Failure mechanism of anchoring body under temperature-pressure coupling in deep soft rock roadway and the engineering application

针对深井软岩巷道高地温高地压锚固支护失锚率增大的问题,以淮南矿区深井软岩巷道为例,采用室内相似模拟试验方法,进行温压耦合作用下锚固体变形破坏特性和锚杆受力特征试验研究。结果表明:随着温度升高和侧压系数的增大,锚固体的破裂深度增大,而侧压系数增大则锚固体的破裂倾角减小。当λ=1.2、1.5和1.8时锚固体的破裂深度分别为托盘直径的1.02~1.2倍、1.13~2.2倍和1.15~2.4倍,锚固体破裂倾角分别为45°~60°、40°~45°和30°~35°;温度升高和侧压系数增大,锚固体压密阶段水平变形量增大,随着侧压系数的增大,温度对锚固体变形破坏规律影响减弱;锚杆在破碎块体作用下处在压、张、剪的复杂应力状态,锚杆以受张拉应力为主,弯曲位置受压、剪应力作用,随着温度和侧压系数的增大,锚杆弯曲位置受压、剪应力增大,锚杆发生明显弯曲变形,锚杆锚固体呈渐进式破坏。将全长锚固支护工艺应用于丁集矿西三轨道大巷围岩支护参数优化设计,并进行现场监测,反馈表明巷道围岩支护效果较好。

Aiming at the increasing anchor failure rate of high ground temperature and high ground pressure anchorage support in deep soft rock roadway,taking a deep soft rock roadway in Huainan mining area as an example,the indoor similar simulation test method was used to study the deformation and failure characteristics of anchor solid and the stress characteristics of anchor under the coupling effect of temperature and pressure.The results show that with the increase of temperature and lateral pressure coefficient,the fracture depth of anchorage body increases,while with the increase of lateral pressure coefficient the fracture angle of anchorage body decreases.Whenλ=1.2,1.5 and 1.8,the fracture depth of the anchorage body is 1.02~1.2,1.13~2.2 and 1.15~2.4 times of the tray diameter,and the fracture dip angles of the anchorage body are 45°~60°,40°~45°and 30°~35°,respectively.With the increase of temperature and lateral pressure coefficient,the horizontal deformation of the anchorage increases in the compaction stage.With the increase of lateral pressure coefficient,the influence of temperature on the deformation and failure of the anchorage weakens.The bolt is in the complex stress state of compression,tension and shear under the action of broken blocks.The bolt is mainly subjected to tension stress,and the bending position is under pressure and shear stress.With the increase of temperature and lateral pressure coefficient,pressure and shear stress on the bending position of the bolt increases,and the bolt has obvious bending deformation.The bolt anchoring body fails progressively.The full-length anchoring support technology is applied to optimize the surrounding rock support parameters of the roadway,and the field monitoring results demonstrate that the support effect is favorable.