A Suggested Methodology for Assessing the Failure Risk of the Final Slopes of Former Open-Pits in Case of Flooding

Abstract

Some valuable minerals, such as lignite, are extracted through open-pit mining works. After the cessation of mining activity, large-scale gaps result in the landscape. These gaps, also called “remaining gaps”, represent some of the roughest types of environmental impacts. After the cessation of mining activity, recovery and ecological restoration works are required. However, it is first necessary to carry out risk assessment studies considering the possible future influences on the final slopes. For this study, flooding of the remaining lignite open-pits gaps was considered as the ecological restoration option. The study was based on extensive research, including sampling, laboratory tests, statistical-mathematical processing, hypothesis formulation, evaluations, interpretations, and field observations, regarding the rock behavior and occurrence of negative geotechnical phenomena (geotechnical phenomena that have a negative impact and a risk on the integrity of the environment and local communities, such as landslides, rockfalls, liquefaction, suffosis) during the flooding process. This paper’s originality consists of combining the methods and methodologies developed with the help of classic methods (Fellenius, Janbu, and Bishop methods) and probabilistic ones (Rosenblueth method) existing in the specialized literature for solving the proposed problem and structuring the information similar to a guide.

Reassessment of the Stability Conditions in the Lignite Open Pits of Oltenia (Romania) in Relation to the New Local Seismic Context as an Imperative for Sustainable Mining

“…In order to highlight the influence that seismic movements in the Oltenia mining region can have on the stability of the mining works in the three studied perimeters, we considered several previous studies, conducted by the authors and their collaborators [1,2,38,41,[59][60][61].…”

“…These characteristics were determined by statistical processing of the data from the determinations made in the Laboratory of Soil Mechanics of the University of Petros , ani, as well as those taken from the specialized studies carried out over the last five decades by the Institute of Scientific Research, Technological Engineering and Mine Designs on Lignite, Craiova, Romania [59].…”

“…Physical-mechanical characteristics used in the stability analyses for Peșteana North perimeter[59].The Nature of Rocks from the Analysis Sections γvnat rocks: fine sand, clayey sand, dusty sand (steps T2-T4, foundation of the interior dump together with a clay layer) rocks: clay, greasy clay, dusty clay, marly clay, dust, clay dust, sandy clay dust (generally in the roof and bed of lignite layers, the direct foundation of the interior dump) marl, clayey marl, sandy marl (steps T1, T3, T4, interspersed between sands and clays) , φnat-Volumetric weight, cohesion and angle of internal friction (at natural moisture).…”

“…-mechanical characteristics used in the stability analyses for Peșteana North perimeter[59].The Nature…”

Ocena stanu stabilności i ryzyka wystąpienia osuwisk w zagłębiu górniczym Berbești (Rumunia) po zamknięciu kopalni

“…Sliding risk assessment analysis is required in particular in conditions of instability of the final slopes. The risk is defined as the product of the probability of landslides and the vulnerability of existing anthropogenic and natural objectives in the influence area of the landslide R = V x Pr (where: R -landslide risk; V -vulnerability -vulnerability of objec- In order to evaluate the risk of landslides in the different hypotheses considered in this study, we used a methodology developed by part of the members of the research team , verified in the completion of master and doctoral thesis, as well as in other scientific articles (Apostu et al, 2021).…”