Uniaxial compressive strength (UCS) is the most used parameter to measure rock strength. However, restrictions in sampling large volume of material, the need of very large set of results and onsite characterisation of UCS non-destructively are requirements in many scientific and engineering investigations. The estimation of UCS from a single non-destructive or minimally invasive technique (NDT) may result incomplete because each NDT is sensitive to different compositional and textural factors.

This paper combines open porosity, P-wave velocity, Leeb hardness and micro-drilling resistance force to estimate USC for a wide range of carbonate sedimentary rock types with different petrographic characteristics. Results reveal that mineralogical composition significatively affects micro-drilling resistance force profiles and P-wave velocity values, especially for quartz-bearing rocks. In addition, texture controls substantially the reproducibility of tests sensible to rock surface properties, such as Leeb hardness and micro-drilling resistance force.

Fifteen simple and multiple expressions for UCS are fitted. Linear expressions have shown better coefficients of determination (R²) than non-linear equations because of the linearity shown by individual parameters. Curve fitting improves as the number of petrophysical parameters increase in the multiple linear regression analysis. The best correlation is found when the equation incorporates all the mechanical parameters obtained non-destructively as well as open porosity (R² = 0.910). Leeb hardness is always the most significant variable of the fitted regressions and its addition into multiple linear equations causes an increase of R². Open porosity also improves R² whereas drilling force and P-wave velocity have a lower statistical weight in the expressions. The UCS estimation from all NDT, without considering open porosity, shows a good correlation (R² = 0.899), which presents the advantage that they can be obtained non-destructively with portable equipment and can provide a numerous set of results at relatively low cost.

单轴抗压强度(UCS) 是测量岩石强度最常用的参数。然而，对大量材料采样的限制、非常大的结果集的需要以及 UCS 的现场非破坏性表征是许多科学和工程调查的要求。从单一的非破坏性或微创技术 (NDT) 估计 UCS 可能会导致不完整，因为每个 NDT 对不同的成分和质地因素敏感。

本文结合开放孔隙度、纵波速度、里氏硬度和微钻阻力来估算具有不同岩相特征的各种碳酸盐沉积岩类型的 USC。结果表明，矿物成分显着影响微钻阻力剖面和 P 波速度值，尤其是对含石英岩石。此外，质地在很大程度上控制着对岩石表面特性敏感的测试的再现性，例如里氏硬度和微钻孔阻力。

适合 UCS 的 15 个简单和多个表达式。由于单个参数显示的线性，线性表达式显示出比非线性方程更好的决定系数 (R ² )。随着多元线性回归分析中岩石物理参数数量的增加，曲线拟合得到改进。当方程包含非破坏性获得的所有机械参数以及开放孔隙率 (R ²  = 0.910)时，可以找到最佳相关性。里氏硬度始终是拟合回归中最重要的变量，将其添加到多元线性方程中会导致 R ²增加。开放孔隙率也提高了 R ²而钻井力和纵波速度在表达式中具有较低的统计权重。所有无损检测的 UCS 估计，在不考虑开放孔隙率的情况下，显示出良好的相关性 (R ²  = 0.899)，其优势在于它们可以用便携式设备无损地获得，并且可以以相对较低的成本提供大量结果.