The safe and efficient mining of deep coal resources is severely restricted by the dynamic disasters caused by high gas and high ground stress. Taking a deep mine in China as the research background, a mechanical model of the front supporting stress with the working face was constructed through theoretical calculations. Based on the limit equilibrium theory, the stress distribution in the plastic zone and the elastic zone of the lateral working face was derived; based on semi-infinite plane mechanics model, the floor vertical and horizontal stress distribution was deduced. Then, the roadway surrounding rock stress and displacement field distribution evolution characteristics were revealed through numerical simulation. On this basis, the reasonable floor gas drainage roadway (FGDR) layout was determined: internal staggered layout was used with FGDR, the vertical distance to the working face is 20 m, and the horizontal distance to the working face end is 15 m; the open-off cut of FGDR was arranged in an external staggered layout, the vertical distance to the working face is 20 m, and the horizontal distance to the open-off cut of the working face is 15 m. It is an important practical significance for the layout of FGDR, the control of surrounding rocks, and the improvement of gas drainage effects under similar conditions through the research results.
With the increase of mining intensity of coal resources, some coal mines in China have gradually entered the deep mining stage. The complexity of the stress environment of the deep rock stratum leads to the difficulty of coal mining. Among them, the control of the deep roadway is one of the bottlenecks restricting the safety mining of the deep coal resources in China. By means of statistical analysis, the factors affecting the stability of the deep roadway were summed up: roadway occurrence envi...
Last. Serkan Saydam(UNSW: University of New South Wales)H-Index: 14
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Abstract Excessive floor deformation in underground coal mines, known as floor heave, can cause production delays and thus financial losses. This paper presents parametric studies using numerical models to understand the mechanisms of floor heave in coal mine roadways. An Australian longwall coal mine that experienced significant floor heave in the roadways, where a strong floor unit overlying weak floor units is present immediately below the coal seam, was chosen for field observations. Althoug...
#1Haiyang Pan(SDUST: Shandong University of Science and Technology)H-Index: 2
#2Dawei Yin(SDUST: Shandong University of Science and Technology)H-Index: 4
Last. Zhiguo Xia(SDUST: Shandong University of Science and Technology)H-Index: 1
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Crack initiation is an important stage in the failure process of rock masses. In this paper, crack initiation behaviors (crack initiation model, crack initiation location, crack initiation angle, and crack initiation stress) of granite specimens containing crossing-double-flaws with different lengths were investigated using PFC2D software. Crack initiation models were all tensile wing cracks, which did not exactly initiate from the main flaw with a length of 30 mm. They can initiate from the sec...
#2Manchao He(CUMT: China University of Mining and Technology)H-Index: 26
Last. Zhigang Tao(CUMT: China University of Mining and Technology)H-Index: 14
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The failure mechanism of anti-dip layered slopes is essentially different from that of dip layered slopes. Therefore, it is important to investigate the failure mechanism of anti-dip slopes due to excavations. In this study, slope instability induced by mining excavation at the Changshanhao open-pit mine in Neimenggu province, China, was used as a case study. Based on the similarity ratio theory, a physical model was built to investigate the failure mechanism of the anti-dip layered slope under ...
#1Hongwen Jing(CUMT: China University of Mining and Technology)H-Index: 17
#2Jiangyu Wu(CUMT: China University of Mining and Technology)H-Index: 5
Last. Ke Wang(CUMT: China University of Mining and Technology)H-Index: 7
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Abstract This paper investigated the stress evolution, displacement field, local deformation and its overall distribution, and failure characteristics of the anchorage structure of surrounding rock with different rockbolt spacing through the model experiments. The influences of the pre-tightening force and spacing of rockbolt on the support strength of the anchorage structure of surrounding rock were analyzed by the simulation using FLAC3D numerical software. The support scheme of the excavated ...
The pore-throat structures play a dominant role in the evaluation of properties of tight sandstone, but it remains difficult to determine the related parameters and understand their impact on reservoir quality. Hence, toward this end, we analyze the experimental data that are indicative of the pore-throat system, then we investigate the effect of fractal dimensions of pore-throat structures on petrologic and physical properties, and finally, the optical observations, fractal theory, and predicti...
#1Guichen Li(CUMT: China University of Mining and Technology)H-Index: 11
#2Yuantian Sun(CUMT: China University of Mining and Technology)H-Index: 14
Last. Ruiyang Bi(CUMT: China University of Mining and Technology)H-Index: 1
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Improving roadway stability in deep underground mines is quite challenging, as the conventional support structures easily fail. Roadway collapse and large deformation occur just several months after tunnel excavation. In this study, a relatively new prereinforcement technique, the jet grouting (JG), is introduced to improve roadway stability. A field test was performed for evaluating the practicability and applicability of JG in soft coal mass. A series of laboratory tests were conducted to asse...
#1Xiaofei Wang(Shandong Institute of Business and Technology)H-Index: 3
#2Chuangeng Liu(Shandong Institute of Business and Technology)H-Index: 4
Last. Na Liu(Shandong Institute of Business and Technology)H-Index: 1
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Abstract Coal is the main energy source of China. A decline in coal prices caused by overcapacity not only determines the survival of coal enterprises but also directly affects economic growth, energy security and industrial raw material supply. This study uses the difference-in-differences model to quantitatively evaluate the treatment effect of coal de-capacity policies on coal prices. Empirical results are summarised as follows. Firstly, the de-capacity policy positively influenced coal price...
The stability of the surrounding rock is the key problem regarding the normal use of coal mine roadways, and the floor heave of roadways is one of the key factors that can restrict high-yield and high-efficiency mining. Based on the 1305 auxiliary transportation roadway geological conditions in the Dananhu No. 1 Coal Mine, Xinjiang, the mechanism of roadway floor heave was studied by field geological investigation, theoretical analysis, and numerical simulation. We think that the surrounding roc...
#1Pu Wang(SDUST: Shandong University of Science and Technology)H-Index: 8
#2Lishuai Jiang(SDUST: Shandong University of Science and Technology)H-Index: 19
Last. Anying Yuan(Anhui University of Science and Technology)H-Index: 1
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The study of evolution laws of the mining-induced stress in floor strata affected by overhead mining is extremely important with respect to the stability and support of a floor roadway. Based on the geological conditions of the drainage roadway in the 10 th district in a coalmine, a mechanical model of a working face for overhead mining over the roadway is established, and the laws influencing mining stress on the roadway in different layers are obtained. The evolution of mining stress in floor ...
Shotcrete material has found extensive applications as a reinforcing material in the engineering sector. This study examined the effect of doped glass fibers on the mechanical performance of the modified shotcrete material composed of aeolian sand, fly ash, cement, quicklime, and doped glass fibers. Its tensile and shear strengths values were experimentally determined via a WAW-1000D computerized hydraulic universal tensile testing machine. Its microstructure was analyzed via a size analyzer, sc...
Last. Ming Luo(CUMT: China University of Mining and Technology)
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The stability of the roadway surrounding rock is the key factor of underground mining. Roof subsidence occurred during roadway excavation in the Menkeqing Coal Mine. For the sake of safety, it was decided to stop tunneling project and strengthen roadway support, which resulted in a delay of the construction period and economic damage. To maintain the stability of the surrounding rock, we carried out a systematic study through field monitoring, theoretical analysis, and numerical simulation. The ...
