软岩表面硬度与抗压强度关联可靠性及内在机理研究

The non-destructive test for surface hardness of soft rock can be applied to estimating uniaxial compressive strength and classifying engineering rock masses. To reveal the relation between surface hardness and compressive strength of soft rock mass, this research, based on surface hardness tests, porosity tests and uniaxial compressive strength tests, will combine laboratory tests, in situ tests and theoretical analysis to investigate typical soft rock in domestic rock engineering. Additionally, this research will adopt fuzzy set theory and non-linear statistical theory to analyze experimental data. The following aspects will be studied: (a) the variation tendency of surface hardness of soft rock with the increase of soaking time and moisture content; (b) relations among porosity, strength parameters and surface hardness with different moisture content of soft rock; (c) the reliability of the method for predicting compressive strength of soft rock through its surface hardness with reliability analysis method; (d) the deformation relation of soft rock according to the surface hardness test and the uniaxial compressive strength test respectively; (e) the application standard for soft rock surface hardness in the classification of engineering rock masses. Finally, softening state equations for soft rock surface hardness and non-linear statistical models for estimating compressive strength will be established, classification criterion for soft rock surface hardness in engineering rock masses will be created, and the relation curves of moisture content, compressive strength and surface hardness for soft rock will be plotted. The research achievements for surface hardness will provide a valuable reference for fast estimating compressive strength of soft rock and classification of engineering rock masses.

非破坏性试验软岩表面硬度测试可用于快速判断软岩单轴抗压强度和工程岩体分级。为了揭示软岩表面硬度与其抗压强度的关系，本项目以软岩表面硬度测试、孔隙度测试和单轴抗压强度测试为基础，采用室内试验、现场试验和理论分析相结合的方法，针对我国岩体工程中常见的软岩，运用模糊集合论和非线性统计学处理试验数据，研究软岩表面硬度随浸水时间、含水率的变化趋势，不同含水率条件下软岩孔隙度、强度参数与表面硬度之间的关系，并用可靠度分析方法研究软岩表面硬度判断其强度参数的可靠性，表面硬度测试与抗压强度测试之间的变形相关性，建立软岩表面硬度的软化状态方程和软岩表面硬度对其抗压强度的非线性统计模型，进而建立软岩表面硬度在工程岩体分级中的应用标准，并且绘制软岩表面硬度与含水率、软岩表面硬度与抗压强度的关系曲线。本项目的研究成果可为快速判断软岩抗压强度和工程岩体分级提供参考。

表面硬度测试是一种非破坏性试验，可用于快速判断单轴抗压强度并应用于工程岩体质量分级。为揭示软岩表面硬度与其抗压强度的关系，本项目以软岩表面硬度测试、孔隙度测试和单轴抗压强度测试为基础，采用室内试验和理论分析相结合的方法，针对我国岩体工程中常见的软岩，运用模糊集合论和非线性统计学处理试验数据，研究软岩表面硬度随浸水时间、含水率的变化趋势，不同含水率条件下软岩孔隙度、强度参数与表面硬度之间的关系，并用可靠度分析方法研究软岩表面硬度判断其强度参数的可靠性，表面硬度测试与抗压强度测试之间的相关性，建立软岩表面硬度与抗压强度的非线性统计模型。表面硬度的测试原理决定了不可能以表面硬度值精确确定岩石单轴抗压强度，而前人的研究主要针对单一类型岩石，本项目通过大量数据分析建立岩石表面硬度与抗压强度的非线性预测模型，用表面硬度值来确定岩石单轴抗压强度所在区间，进而将其应用于岩体分级RMR和BQ中。可避开采集岩样并加工成标准试样的耗时费力过程，特别是软岩采样加工容易出现掉角、不平整现象，以及受水影响的强度急剧下降。本项目研究成果可为快速判断抗压强度和工程岩体分级提供参考。