Point load test is one of the most adopted indirect ways to estimate uniaxial compressive strength of rocks. Yet, the estimation can be interfered by rock porosity which has rarely been considered in model development. In this study, we proposed a theoretical model for the interpretation of point load test results considering the effect of porosity. The model was developed using the elastic stress field inside diametrically loaded sphere within the framework of linear elastic fracture mechanics and requires only basic physical parameters including porosity and Poisson's ratio. Apart from the point load index, an extra parameter, subtended angle, is included in the interpretation, which accounts partly for the wide range of the ratio between point load index and uniaxial compressive strength observed in the experiments. The predictions of proposed model compare reasonably well with data for a variety of rocks, which demonstrates the validity of the model.

中文翻译：

---

孔隙度对岩石单轴抗压强度与点荷载指数关系影响的理论模型

点载荷试验是估算岩石单轴抗压强度最常用的间接方法之一。然而，估计可能会受到岩石孔隙度的干扰，而在模型开发中很少考虑到这一点。在这项研究中，我们提出了一个考虑孔隙率影响的点载荷测试结果解释的理论模型。该模型是在线弹性断裂力学框架内利用直径加载球体内部的弹性应力场开发的，仅需要包括孔隙率和泊松比在内的基本物理参数。除了点载荷指数之外，解释中还包括一个额外的参数，即夹角，这在一定程度上解释了实验中观察到的点载荷指数与单轴抗压强度之间的比率的广泛范围。