Abstract

For the sustainability of lignite and coal mining, engineers need the soils' appropriate geotechnical characterisation of the excavations. This characterisation relates to the slope stability, the overall area stability, and the sustainable exploitation of mining areas during operational and post-closure eras. This work presents a novel perspective on the soil characterisation of lignite mine excavations. Rather than focusing on one particular mine, a comprehensive geotechnical characterisation provides insights about the soils of related mining areas. Additionally, slope stability representative cases guide soil characterisation and analysis rather than following it. The Greek lignite mines are used as a representative example for the illustration of this framework. Initially, the two typical slope stability scenarios for Greek lignite mines are established: a slope in the presence of a weak zone and a homogeneous slope. The crucial geotechnical parameters are then statistically examined based on an extensive database established from laboratory results of various mines. Focus is on shear strength (friction angle and cohesion), the key to slope stability, and physical properties that can provide the strength through empirical correlations. Many soil layers exhibit a low residual friction angle from 5° to 15°, corresponding to the weak zone. Peak friction angle presents a mean value of 28.4°, and a characteristic value of 25.0°; cohesion presents a wide range with a mean value of 111 kPa and a characteristic value of 84 kPa. Finally, cross-correlations between geotechnical parameters present large scatter, but relations for estimating the residual and the peak friction angle reveal general trends.

中文翻译：

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褐煤矿山开采覆盖层材料的全面岩土工程表征

摘要

为了褐煤和煤炭开采的可持续性，工程师需要对土壤进行适当的岩土工程表征。此特征与边坡稳定性，总体区域稳定性以及在运营和关闭后时代对矿区的可持续开发有关。这项工作为褐煤矿山开挖的土壤表征提供了一个新颖的视角。全面的岩土工程特征而不是只关注一个特定的矿山，而是提供了有关相关矿区土壤的见解。此外，具有边坡稳定性的典型案例指导的是土壤的表征和分析，而不是遵循这些描述。以希腊褐煤矿为例来说明这一框架。最初，建立了希腊褐煤矿山的两种典型边坡稳定性情景：存在薄弱区域的边坡和均质边坡。然后，基于从各种矿山的实验室结果建立的广泛数据库，对关键的岩土参数进行统计检查。重点是剪切强度（摩擦角和内聚力），边坡稳定性的关键以及可以通过经验相关性提供强度的物理特性。许多土壤层在5°至15°之间显示出较低的残余摩擦角，对应于薄弱区域。峰值摩擦角的平均值为28.4°，特征值为25.0°。内聚力表现出很大的范围，平均值为111 kPa，特征值为84 kPa。最后，岩土参数之间的互相关呈现出较大的分散性，