Analytical and numerical method assessing the risk of sinkholes formation in mining areas  

作　　者：Piotr Strzalkowski Krzysztof Tomiczek 

机构地区：[1]Faculty of Mining and Geology, Silesian University of Technology

出　　处：《International Journal of Mining Science and Technology》2015年第1期85-89,共5页矿业科学技术学报（英文版）

摘　　要：Voids, which have not been liquidated and associated with shallow mining excavations, pose a serious threat of potential formation of sinkholes. This threat is connected with the loss of stability of voids that had been formed as a result of mining operations in the deeper strata. Taking into account the impact of lower coal seams mining on shallow excavations and based on the example of a region that had been intensely exploited, this paper proposes a methodology for analysing the stability of shallow mine voids in the rock mass. Deformations in the excavation region were calculated by using FLAC2D computer pro- gram and assigning the Coulomb-Mohr model to the rock mass. Based on the numerical analysis, this paper evaluated the stability of the void in the event of a roof support fall. The results indicate the like- lihood of void formation. Based on the Budryk-Knotbe theory, the deformations of rock mass and sand- stone strata in the roof of the void, which had been caused by mining exploitation in consecutive years, were calculated. The results of numerical calculations and analyses were compared with the limit defor- mations values of sandstone in tension. It is concluded that the exploitations cause the void to break down. The proposed method can forecast the discontinuous deformations threats in the areas that have undergone shallow undermining exploitation and the areas of underground urban.Voids, which have not been liquidated and associated with shallow mining excavations, pose a serious threat of potential formation of sinkholes. This threat is connected with the loss of stability of voids that had been formed as a result of mining operations in the deeper strata. Taking into account the impact of lower coal seams mining on shallow excavations and based on the example of a region that had been intensely exploited, this paper proposes a methodology for analysing the stability of shallow mine voids in the rock mass. Deformations in the excavation region were calculated by using FLAC2 D computer program and assigning the Coulomb–Mohr model to the rock mass. Based on the numerical analysis, this paper evaluated the stability of the void in the event of a roof support fall. The results indicate the likelihood of void formation. Based on the Budryk–Knothe theory, the deformations of rock mass and sandstone strata in the roof of the void, which had been caused by mining exploitation in consecutive years,were calculated. The results of numerical calculations and analyses were compared with the limit deformations values of sandstone in tension. It is concluded that the exploitations cause the void to break down. The proposed method can forecast the discontinuous deformations threats in the areas that have undergone shallow undermining exploitation and the areas of underground urban.

关 键 词：Mining exploitationDiscontinued deformationsSinkholesStabilityRisk of sinkhole formationTensile deformations of rocks 

分 类 号：TD327[矿业工程—矿井建设]