The impact of deep underground coal mining on Earth fissure occurrence

Abstract

Deep underground mining commonly causes land subsidence and mining tremors. The occurrence of Earth fissures induced by deep underground mining operations is a rare phenomenon. The development of Earth fissures is a rapid and unexpected process causing a particular hazard to the developed areas. The presented research focuses on the investigation of Earth fissure propagation in the light of geotechnical and geological condition. The presented approach can be used for establishing most significant risk factors influencing Earth fissure development in the areas induced by deep mining. ARTICLE INFO

Occurrence of Linear Discontinuous Deformations in Upper Silesia (Poland) in Conditions of Intensive Mining Extraction—Case Study

“…In some papers, attention has been paid to a certain threshold value of horizontal strain caused by the underground exploitation of deposits. It has been reported [9,18,19] that linear discontinuous deformations have been observed when the horizontal tensile strain has exceeded the value of 9 mm/m. Following these findings, the same value of threshold strain was thus determined for two Polish mining regions [9,18] and a Chinese basin [19].…”

“…It has been reported [9,18,19] that linear discontinuous deformations have been observed when the horizontal tensile strain has exceeded the value of 9 mm/m. Following these findings, the same value of threshold strain was thus determined for two Polish mining regions [9,18] and a Chinese basin [19]. In his paper [5], Kowalski noted that primary discontinuous deformations are formed at values of horizontal tensile strain exceeding 9 mm/m, whereas secondary deformations can occur even when these values grow by ca.…”

“…It should be noted that the occurrence of linear discontinuous deformations is particularly dangerous for buildings on the surface and depends on a number of factors indicated above. It should be highlighted that the papers referred to above described case studies of the formation of linear discontinuous deformations in the most frequently encountered forms-namely ground steps and fissures (Strzałkowski,Ścigała [9], Malinowska, Hejmanowski [18], Kowalski [5]). In regards to the occurrence of tectonic faults as a factor contributing to the occurrence of the deformations, it has to be noted that the faults were characterized by high throw values, ranging from ca.…”

Factors that trigger the development of mining-induced ground fissures, and standards to treat them in shallow coal mining areas

“…Vegetation withers and dies when soil moisture is lost through these ground fissures, such that the surrounding ecosystems are changed irreversibly (Dagvadorj, Byamba, and Ishikawa, 2018). Ground fissures also compromise the safety of underground mining activities, especially when these fissures extend downwards and connect with the fracture zone of strata, resulting in gas leakages, outbursts of water and sand, and other accidents (Hu, Wand, and He, 2014;Malinowska and Hejmanowski, 2016).…”

“…Secondly, although studies have shown that there is a linear relationship between the width of the ground fissure during development and the horizontal deformation of the surface, the factors that control the formation of the ground fissure are still not clear. Third, because dynamic fissures can self-heal (Malinowska and Hejmanowski, 2016), researchers have proposed that fissures should be remediated once the surface has stabilized after subsidence. However, engineers have found that the depth to which ground fissures and rock fractures penetrate influences the safety of the mining operations, especially in shallow coal seam mines.…”