大理岩点荷载强度与抗压和抗拉强度的关系

点荷载试验是一种快速测定岩石强度的方法。本文以广东阳江地区大理岩为研究对象,开展了点荷载以及巴西劈裂等试验研究。采用不同的加载方式(轴向试验和径向试验)进行点荷载试验,讨论规范中建议的修正指数m对点荷载强度的影响,结果表明：采用规范建议的修正指数m=0.4～0.45修正得到的点荷载试验标准值Is(50)与直接由径向加载试验得到Is(50)差别不大,但采用m=0.5修正更精确。结合室内的几种强度试验的分析,获得了大理岩单轴抗压强度Rc和单轴抗拉强度Rt的与点荷载试验标准值Is(50)之间的经验转换关系式。

Study on the Relation between Point Load Strength and Compressive and Tensile Strength of Marble

Point load test is a fast method for determining rock strength. In this paper, the marble in Yangjiang area of Guangdong Province is taken as the research object, and the point load test and Brazilian splitting test are carried out. Point load tests are carried out with different loading modes (axial and radial tests). The influence of the modified index m proposed in the code on the point load strength is discussed. The results show that the standard value of point load test Is(50) obtained by the modified index m=0.4-0.45 proposed in the code is not different from that obtained directly from the radial load test, but the modified index m=0.5 is more accurate. Based on the analysis of several indoor strength tests, the empirical conversion formulas between the uniaxial compressive strength Rc and uniaxial tensile strength Rt of marble and the standard value of point load test Is(50) are obtained.