Investigation on fracture models and ground pressure distribution of thick hard rock strata including weak interlayer

Yu, Meilu; Zuo, Jianping; Sun, Yajun; Mi, Changning; Li, Zhengdai

doi:10.1016/j.ijmst.2021.10.009

Cited by 54 publications

(21 citation statements)

References 28 publications

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“…Shu et al(2015) analyzed the thick and hard igneous rock of the protective layer under the fault evolution law of the overlying strata, as well as the cause of the gas outburst accidents. Yu et al(2022) deeply analyzed the influence of the position of weak interlayer on the fracture mode of rock stratum and formation pressure. Li et al(2017) deduced the theoretical formula of the periodic breaking span of THRS based on Vlasov plate theory, and studied the distribution characteristics of strain energy density during the mining process by numerical simulation.…”

Section: Instructionmentioning

confidence: 99%

Numerical simulation of progressive failure law of thick-hard rock strata in the upper coal seam

Zhao

Wang

et al. 2023

Preprint

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The thick-hard rock strata (THRS) are widely distributed among coal-bearing strata. In the process of coal mining, the strong dynamic load will be produced after the THRS are broken, which will lead to dynamic disasters such as mine earthquake, rock burst and so on. Therefore, revealing the breaking law of THRS is helpful to prevent and control the dynamic disasters. This paper constructed the mechanical model of THRS based on thick plate theory and obtained the breaking distance of THRS, which is applied to Yangliu Coal Mine. And we constructed the numerical stratigraphic model and analyzed the caving characteristics, the changing rules of displacement and stress of THRS under different advancing distances. Then the above results are verified by the change of hydraulic support resistance. The research shows that the critical instability distance of THRS overlying the coal seam #10 in Yangliu Coal Mine was 296.4 m. Based on the numerical simulation, the displacement and stress of the main THRS increased greatly at the position of 250-300 m, and occurred a large-scale collapse. The hydraulic support resistance of the working face increased sharply and microseismic energy is released rapidly when the mining reached about 330 m, the reliability of the theoretical analysis and numerical simulation were verified by the engineering tests.

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Section: Instructionmentioning

confidence: 99%

Numerical simulation of progressive failure law of thick-hard rock strata in the upper coal seam

Zhao

Wang

et al. 2023

Preprint

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“…During the mining process of the lower coal seam, the interlayer rock strata are broken, and the upper and lower goafs are connected to form a composite goaf. The coal and rock mass in the overlying goaf are broken repeatedly, and the cracks are developed to the surface again [7,[33][34][35]. Under the action of ground pressure difference, air enters the goaf through cracks, the surface air leakage not only leads to the abnormal gas emission in the goaf, the low oxygen phenomenon in the working face is frequent [17,36,37].…”

Section: Introductionmentioning

confidence: 99%

Study on the mechanism and control of strong ground pressure in the mining of shallow buried close-distance coal seam passing through the loess hilly region

He,

Huang,

2024

Preprint

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Shallow buried close-distance coal seam (SBCCS) is widely found in northern Shaanxi, China. In the process of mining under the loess hilly area (LHA) in SBCCS, many accidents of strong ground pressure have occurred. Taking the in the Zhangjiamao Coal Mine as the background, this study revealed the mechanism of high ground pressure when the working face of lower coal seam passes through the surface loess hilly region. On-site measurements, physical similarity simulation, numerical calculation, and theoretical analysis were combined to study the mining process of SBCCS. The movement characteristics of the activated structure of the interval strata of the lower coal seam were analyzed. The dynamic load and the change pattern of the front abutment pressure (FAP) of the support during the loading stage of entering and exiting the loess hilly were determined. A coupled structural mechanics model of the overlying activated voussoir beam and the step voussoir beam rock beam of the interval strata was established, revealing the dynamic loading mechanism of strong ground pressure during passing through the LHA . The results showed that the dynamic load of the working face was the highest in areas affected by the load of the LHA, followed by the load while entering the LHA , the peak value of the FAP in the load-influenced LHA was high, which was approximately 1.12 times that after leaving the load-influenced LHA and 1.61 times that before entering this area. By establishing a mechanical model of the roof coupling structure when entering and exiting the load-influenced LHA, it was revealed that the dynamic load of the support while mining under the goaf in the LHA is mainly due to the synchronous movement of the activated structure of the collapsed roof of the upper coal seam and the interval rock structure. The load in the LHA was transmitted to the interval rock structure through the activated structure, resulting in a high dynamic load on the support. The study concluded that the determination of the support resistance of the working face should be based on the high-period compressive load of the synchronous movement of the roof structure in the loess hilly beam area. Through the engineering practice of hydraulic fracturing, the roof structure of the interval strata is changed, which can effectively reduce the dynamic pressure disaster of the working face. The research provides a scientific basis for the safe and efficient mining of shallow coalfields, and it provides reference for similar mining.

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“…Based on the stress evolution law of roadways under repeated mining and the asymmetric evolution characteristics of the plastic zone in the Shendong mining area, (Wu, 2018), (Wu, 2020), and Lv et al (2019) revealed the malignant expansion mechanism of the plastic zone of the roadway surrounding rock and presented a hierarchical stability control system of the roadway surrounding rock. Yu et al (2021) studied the fracture mode and abutment pressure distribution of a thick and hard rock roof with a weak interlayer. (Kang and Zhong (2016b) studied the influence of working face abutment pressure on the stability of roof rock that was strengthened using a bolt through physical and numerical simulation.…”

Section: Introductionmentioning

confidence: 99%

Failure mechanism and support system of roofs in advance areas affected by mining under the condition of soft rock stratum

Lian

et al. 2022

Front. Earth Sci.

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The advance area affected by mining (AAAM) of the Lijiahao coal mine is influenced by the superposition of the side and advance abutment pressure, and the roadway roof is considerably damaged. General support technology and equipment cannot economically and effectively maintain the stability of the roadway roof of AAAM. Through field detection, theoretical analysis, and numerical simulation, this study analyzes the structure of the surrounding rock, the evolution characteristics of the regional stress field, the distribution of the surrounding rock plastic zone, and the influencing factors of the plastic zone in the AAAM of the Lijiahao mine. The results show the following: 1) the direct roof and floor of the roadway comprise coal, siltstone, and sandy mudstone, which has low strength and can be easily broken. 2) The maximum and minimum principal stresses in the AAAM reach 2.3 and 1.5 times of in situ stress, respectively, and the ratio of the two stresses reaches 2–8, which causes the shape of the plastic zone of the surrounding rock to turn into a butterfly shape. 3) The principal stress direction of AAAM deflects at a large angle, which causes the deepest failure direction of the surrounding rock to rotate to the roof and floor of the roadway. Accordingly, a self-moving foldable support system is proposed to support the AAAM of the Lijiahao coal mine. The system will not support the roof repeatedly and is suitable for soft rock stratum. In addition, it can also adapt to the heave of roadway floor and avoid dumping. The mechanized operation of the system makes the roof support in AAAM more efficient and safer.

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Investigation on fracture models and ground pressure distribution of thick hard rock strata including weak interlayer

Cited by 54 publications

References 28 publications

Numerical simulation of progressive failure law of thick-hard rock strata in the upper coal seam

Numerical simulation of progressive failure law of thick-hard rock strata in the upper coal seam

Study on the mechanism and control of strong ground pressure in the mining of shallow buried close-distance coal seam passing through the loess hilly region

Failure mechanism and support system of roofs in advance areas affected by mining under the condition of soft rock stratum

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