The essential task of the ground reinforcement techniques is to keep the rock as stable as possible. In particular passive rock bolt should resist the rock movements along its entire length and through the resulting reaction forces, to improve the load-bearing capacity of the rock. Among different calculation techniques, the calculations based on Block Reinforcement Procedure (BRP) was used in this paper, also adopting some simplified equations available in the scientific literature. However, parameters influencing the interaction are difficult to evaluate. Therefore, the problem of the reliable definition of the parameters that most influence the behavior of the bolts and the evaluation of the stabilizing forces of the potentially unstable block of rock remains. A new probabilistic approach is presented in this article, able to appropriately manage the uncertainties present on the fundamental parameters of the bolt-rock interaction and on the mechanical characteristics of the sliding surface of the block. Through the use of a Monte Carlo procedure, in fact, it was possible to obtain different samples of the safety factors of the rock block, one for each diameter of the steel bars used for its stabilization. Finally, the probabilistic management of the safety factor samples allowed the correct design of the steel bars, by evaluating the probability that the safety factor of the block with regard to potential slipping has a value lower than a pre-established limit. The probabilistic approach developed was applied to a real problem of stabilization of a potentially unstable rock block due to planar sliding, present on a municipal road in North Italy.

地面加固技术的基本任务是保持岩石尽可能稳定。特别是被动式岩石锚杆应抵抗岩石沿其整个长度的运动，并抵抗由此产生的反作用力，以提高岩石的承载能力。在不同的计算技术中，本文采用了基于块体增强程序（BRP）的计算方法，并且还采用了一些科学文献中可用的简化方程。但是，影响相互作用的参数很难评估。因此，仍然存在可靠定义最影响螺栓性能的参数以及评估潜在不稳定岩石块的稳定力的问题。本文介绍了一种新的概率方法，能够适当地管理螺栓-岩石相互作用的基本参数以及砌块滑动表面的机械特性方面的不确定性。实际上，通过使用蒙特卡洛程序，可以获取岩石块安全系数的不同样本，每个样本用于稳定岩石​​的每个直径。最后，安全系数样本的概率管理通过评估块体关于潜在滑移的安全系数具有低于预定极限的值的概率，可以对钢筋进行正确的设计。所开发的概率方法用于解决意大利北部市政道路上由于平面滑动而潜在不稳定的岩石块稳定的实际问题。