UCS under different rock size.

As a basic parameter of rock, the rock bridge angle plays an important role in maintaining the stability of rock masses. To study the size effect of rock bridge angle on the uniaxial compressive strength of rocks, this paper adopts the principle of regression analysis and combines numerical simulation to carry out relevant research. The research results indicate that: (1) the uniaxial compressive strength decreases with the increase of the rock bridge angle, showing a power function relationship; (2) The uniaxial compressive strength decreases with the increase of rock size and tends to stabilize when the rock size is greater than 350 mm, showing a significant size effect. (3) The fluctuation coefficient of compressive strength increases with the increase of rock bridge angle and decreases with the increase of rock size; When the rock size is 350 mm, the fluctuation coefficient is less than 5%; (4) The characteristic compressive strength and characteristic size both increase with the increase of the rock bridge angle.

岩桥角（rock bridge angle）作为岩石的基本参数之一，对维持岩体稳定性具有重要作用。为探究岩桥角对岩石单轴抗压强度（uniaxial compressive strength）的尺寸效应，本文采用回归分析原理并结合数值模拟开展相关研究。研究结果表明：(1) 单轴抗压强度随岩桥角的增大呈降低趋势，二者符合幂函数关系；(2) 单轴抗压强度随岩石尺寸的增大而降低，当岩石尺寸大于350mm时趋于稳定，表现出显著的尺寸效应；(3) 抗压强度波动系数（fluctuation coefficient）随岩桥角的增大而升高，随岩石尺寸的增大而降低；当岩石尺寸为350mm时，波动系数小于5%；(4) 特征抗压强度（characteristic compressive strength）与特征尺寸（characteristic size）均随岩桥角的增大而升高。