Development mechanism of mining-induced ground fissure for shallow burial coal seam in the mountains area of southwestern China: a case study

Abstract

Mining-induced ground fissure (MIGF) contributes to vegetation deterioration, landslides and other natural hazards. The study is an attempt to reveal the development type, dynamic development process, and formation mechanism of MIGF for MIGF-induced natural hazard prevention of shallow burial coal seam mining. A novel approach including in situ measurement, theoretical analysis, and numerical simulation was implemented. There are two typical types of fissures, namely sliding-type ground fissures and stepped-type ground fissures. Sliding-type ground fissures generally develop in a mountainous slope with a large gradient while steppedtype ground fissures typically occur in a mountainous slope with a small gradient and especially near a valley. Dynamic development process of MIGF is significantly affected by roof periodic movement. The advancing distance of a sliding-type ground fissure is 1.35 times periodic weighting step distance while it corresponds to 0.89 times the periodic weighting step distance for a stepped-type ground fissure. A positive relationship exists between horizontal tensile deformation and MIGF width. The movement mode of "voussoir beam" is favorable for slidingtype ground fissure development while the movement mode of "stepped beam" leads to steppedtype ground fissure development. These results can contribute to MIGF treatment and ecological protection in the southwestern mountainous area.

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

“…3 mm/m. A statistical relationship between the value and size of the deformations has been reported [20]. This also indicates a number of important factors determining the formation of linear deformations (fissures).…”

“…30 to 450 m. Grabens are another form of deformations that are observed less frequently but pose a greater threat to buildings. The works by Zhu [20] and Kang [21] indicated that they occur in mountain terrains or at least steep slopes. This leads to the following questions: Is it the case that the only factor conductive to the occurrence of discontinuous linear deformations are faults characterized by a throw of several dozen and more meters?…”

New research on a case of Linear Discontinuous Ground Deformation (LDGD)

“…In recent years, there have also been reports of LDGD in Chinese hard coal mining, with two types of fissures in mountainous areas: slide-type on the slopes, and step-type in valleys [5]. The relationship between the LDGD fissure width and the horizontal strain value was also shown (Fig.…”

“…The relationship between the ground fissure width and the horizontal strain value[5].thickness of the younger layers (above the Carboniferous) is about 200 m on the southern side and about 250 m on the northern side of Fault II. They are built of a thin quaternary layer and a thick tertiary layer.…”

Dynamic Changes in Surface Damage Induced by High‐Intensity Mining of Shallow, Thick Coal Seams in Gully Areas

“…is system was defined in terms of the structure, motion, and fissure distribution of the key strata and aquifuge [10][11][12]. Yu et al studied the formation mechanism of mining-induced fissures in shallow coal seam mines and proposed preliminary control techniques [13,14]. In addition, other scholars in this field have carried out research on strata movement, mining subsidence, ecological restoration, etc.…”