The stability control of fissured rock is difficult, especially under static and dynamic loads in deep coal mines. In this paper, the dynamic mechanical properties, strain rate evolution and energy dissipation of fissured and anchored rocks were respectively obtained by SHPB tests. It was found that bolt can provide supporting efficiency-improving effect for fissured rock against dynamic disturbance, and this effect increased quadratically with decrease in anchoring angles. Then, the energy dissipation mechanism of anchored rock was obtained by slipping model. Furthermore, bolt energy-absorbing mechanism by instantaneous tensile-shear deformation was expressed based on material mechanics, which was the larger the anchoring angle, the smaller the energy absorption, and the less the contribution to supporting efficiency improvement. On this basis, the functional relationship between energy dissipation of anchored rock and energy absorption of bolt was established. Taking the coal-gangue separation system of Longgu coal mine as an example, the optimal anchoring angle can be determined as 57.5°–67.5°. Field monitoring showed fissured rock with the optimal anchoring angle, can not only effectively control the deformation, but also fully exert the energy-absorbing and efficiency-improving effect of bolt itself. This study provides guidance to the stability control and supporting design for deep engineering under the same or similar conditions.

中文翻译：

---

深部煤矿动静荷载作用下锚杆对裂隙岩体支护作用的能量机制


裂隙岩体的稳定性控制十分困难，尤其是在深部煤矿静、动荷载作用下。本文通过SHPB试验分别获得了裂隙和锚固岩石的动态力学特性、应变率演化和能量耗散。研究发现，锚杆可以为裂隙岩体提供抗动力扰动的支护增效效果，且这种效果随着锚固角度的减小而呈二次方增加。然后，通过滑移模型得到了锚固岩石的能量耗散机制。进一步，根据材料力学表达了螺栓通过瞬时拉剪变形吸收能量的机理，即锚固角度越大，吸收能量越小，对支护效率提升的贡献越小。在此基础上，建立了锚固岩石耗能与锚杆吸能之间的函数关系。以龙固煤矿煤矸石分离系统为例，最佳锚固角度可确定为57.5°~67.5°。现场监测表明，裂隙岩体采用最佳锚固角度，不仅能有效控制变形，还能充分发挥锚杆本身的吸能增效作用。该研究可为相同或相似条件下深部工程的稳定性控制及支护设计提供指导。