Rock mass characterization offers the basis of the stability criterion for the planning and advancement of civil engineering projects. Rock core index (RCI) is one of the key geotechnical parameters adopted in rock mechanics and rock engineering. RCI provides risk assessment regarding the success criteria of engineering design. Consequently, an accurate estimate of such parameters is a challenging task in the context of credibility, budget, and time. However, the traditional estimation of geomechanical parameters needs lots of drilling tests at some selected points. The point-scale data often cause more ambiguity and less authenticity in engineering design. Besides, the conventional approaches are invasive, uneconomical, and laborious and cannot investigate the complete project site. We offer an indirect technique for the estimate of RCI using empirical relationships between drilling and geophysical data, which addresses the drawbacks of the conventional methods. Geophysical techniques offer the subsurface volumetric data and are faster, more affordable, and easier to use. In this study, we employ a non-invasive CSAMT (controlled-source audio-frequency magnetotellurics) method for the first time to quickly assess 2D and 3D RCI models. The suggested approach assesses the intricate geological subsurface at a depth of 1 km in order to produce a more precise and complete image of the quality of the rock mass across a wide area. These findings are crucial for improving our understanding of the intricate geological conditions, estimating the likelihood of failure early on, and supporting the safe, stable, and cost-effective construction of deep underground engineering structures. In regions where there is a deficiency of mechanical drilling data, our approach decreases the gaps between an appropriate geotechnical model and insufficient data, yields more objective indices, and serves as a guide for more correct engineering structure design.

中文翻译：

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使用非侵入性地球物理方法估算地下基础设施开发的岩心指数


岩体表征为土木工程项目的规划和推进提供了稳定性标准的基础。岩心指数（RCI）是岩石力学和岩石工程中采用的关键岩土参数之一。 RCI 提供有关工程设计成功标准的风险评估。因此，在可信度、预算和时间方面，准确估计这些参数是一项具有挑战性的任务。然而，传统的地质力学参数估算需要在某些选定点进行大量的钻井试验。点尺度的数据往往会导致工程设计中更多的模糊性和更少的真实性。此外，传统方法具有侵入性、不经济、费力且无法调查完整的项目现场。我们提供了一种利用钻井和地球物理数据之间的经验关系来估计 RCI 的间接技术，解决了传统方法的缺点。地球物理技术提供地下体积数据，速度更快、价格更便宜且更易于使用。在这项研究中，我们首次采用非侵入性 CSAMT（受控源音频大地电磁学）方法来快速评估 2D 和 3D RCI 模型。建议的方法评估 1 公里深度的复杂地下地质，以便对大范围的岩体质量产生更精确、更完整的图像。这些发现对于提高我们对复杂地质条件的了解、早期评估故障的可能性以及支持安全、稳定和经济高效的深层地下工程结构施工至关重要。 在机械钻孔数据缺乏的地区，我们的方法缩小了适当的岩土模型与数据不足之间的差距，产生更客观的指标，并为更正确的工程结构设计提供指导。