基于尺寸效应的类岩石材料点荷载指标与单轴抗压强度对应关系研究  

Correlation Between Point Loading Index and Uniaxial Compressive Strength of Rock-like Material Based on Size Effect

作　　者：林军 沙鹏[1,2] 伍法权 常金源[1,2] 

机构地区：[1]绍兴文理学院土木工程学院,浙江绍兴312000 [2]绍兴文理学院岩石力学与地质灾害实验中心,浙江绍兴312000 [3]浙江省交通规划设计研究院,杭州310000

出　　处：《长江科学院院报》2018年第3期34-44,共11页Journal of Changjiang River Scientific Research Institute

基　　金：中央高校基础科研业务费专项(310821171125)

摘　　要：点荷载强度指标间接确定岩石的单轴抗压强度,具有独特的优势,被认为是一种现场测定、估算单轴抗压强度的最佳方法。通过总结大量国内外相关文献发现,目前的研究成果受岩石材料各向异性、数据模糊对应、仪器笨重、缺乏试验验证4个方面的影响,仍存在局限性。利用自行研制的便携式点荷载仪,针对各向同性的类岩石材料进行不同强度、不同尺寸、一一对应的点荷载指标和单轴抗压强度对应关系试验研究。试验结果表明:试验数据均服从正态分布规律,集中趋势明显;不同尺寸的测试结果证实,类岩石材料的点荷载指标具有明显的尺寸效应;结合实测数据,通过绘制P-D_e^2关系曲线的修正方法得到相关系数最高为0.97,说明不规则样品的点荷载指标能够很好地统一到标准等效尺寸。采用统计分析方法建立点荷载指标和单轴抗压强度的线性方程,对应关系的相关系数为0.994,说明修正后的点荷载指标能够更好地建立相关性、提高精确度。通过不规则试件的点荷载测试验证上述关系式误差在15%以内。The point load intensity index is considered as the optimum method for measuring and estimating uniaxial compressive strength as it is of unique advantage by indirecdy determining the uniaxial compressive strength of rock. By summing up a large number of literatures in China and abroad, we found that current research results are limited by the anisotropy of rock materials, fuzzy correspondence of data, heavy equipment and lack of experimental verifi-cation. In this paper, we researched the correlation between point load index and uniaxial compressive strength of rock-like isotropic material of different sizes and strengths by using a portable instrument for point load test. Accord- ing to test results we conclude that the test data follows the normal distribution law with obvious central tendency; size effect of rock-like material on point load index is apparent; according to P-Z）： curve,the highest correlation co- efficient is 0.97, indicating that the point load index of irregular samples can be rectified to that of standard equiva-lent size. Furthermore, the relational expression between point load index and uniaxial compression strength is es-tablished, with a correlation coefficient up to 0.994, which suggest that the rectified point load index well reflects the correlation and improves calculation accuracy. Finally, through point load test of irregular specimens, the error of the proposed relational expression is verified within 15%.

关 键 词：类岩石材料 点荷载指标 单轴抗压强度 尺寸效应 统计方法 

分 类 号：TU45[建筑科学—岩土工程]