To better understand the failure behaviours and strength of bolt-reinforced blocky rocks, large scale extensive laboratory experiments are carried out on blocky rock-like specimens with and without rockbolt reinforcement. The results show that both shear failure and tensile failure along joint surfaces are observed but the shear failure is a main controlling factor for the peak strength of the rock mass with and without rockbolts. The rockbolts are necked and shear deformation simultaneously happens in bolt‑reinforced rock specimens. As the joint dip angle increases, the joint shear failure becomes more dominant. The number of rockbolts has a significant impact on the peak strain and uniaxial compressive strength (UCS), but little influence on the deformation modulus of the rock mass. Using the Winkler beam model to represent the rockbolt behaviours, an analytical model for the prediction of the strength of bolt-reinforced blocky rocks is proposed. Good agreement between the UCS values predicted by proposed model and obtained from experiments suggest an encouraging performance of the proposed model. In addition, the performance of the proposed model is further assessed using published results in the literature, indicating the proposed model can be used effectively in the prediction of UCS of bolt-reinforced blocky rocks.

中文翻译：

---

有无锚杆块状岩体破坏行为及强度模型


为了更好地了解锚杆加固块状岩石的破坏行为和强度，对有和没有锚杆加固的块状岩石样本进行了大规模的实验室实验。结果表明，沿节理面同时存在剪切破坏和拉伸破坏，但剪切破坏是有或无锚杆岩体峰值强度的主要控制因素。岩石锚杆被颈缩，并且锚杆加固的岩石样本同时发生剪切变形。随着节理倾角增大，节理剪切破坏变得更加占主导地位。锚杆数量对峰值应变和单轴抗压强度（UCS）影响较大，但对岩体变形模量影响不大。使用温克勒梁模型来表示岩石锚杆的行为，提出了一种预测锚杆加固块状岩石强度的分析模型。所提出的模型预测的 UCS 值与实验获得的 UCS 值之间的良好一致性表明所提出的模型具有令人鼓舞的性能。此外，利用文献中已发表的结果进一步评估了所提出模型的性能，表明所提出的模型可以有效地用于预测锚杆加固块状岩石的UCS。