Method to Calculate Working Surface Abutment Pressure Based on Key Strata Theory

Han, Hongkai; Xu, Jialin; Wang, Xiaozhen; Xie, Jianlin; Xing, Yantuan

doi:10.1155/2019/7678327

Cited by 25 publications

(27 citation statements)

References 33 publications

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“…Mining stress mainly affects the surrounding rock stress conditions and the strength parameters of the surrounding rock. According to the research results on the abutment pressure in [30][31][32][33][34], the exponential model is used to describe the abutment pressure, which is used to estimate the vertical pressure σ V (l) of the surrounding rock:…”

Section: Effect Of Mining Stressmentioning

confidence: 99%

“…According to the in situ stress test results, σ 0 V is 16.8 MPa; σ 0 H is 13.3 MPa; τ 0 is 0.5 MPa; λ is 0.79; η is 0.03. According to [30][31][32][33][34], as well as field mine pressure observation results, mining height, mining speed, hydraulic support parameters, and other relevant data, let k s � 1.9, a � 0.1, and b � 0.03. When the distance between the roadway and the working face is more than 250 m, the roadway is not affected by mining stress.…”

Section: Distribution Law Of Mining Stress In Roadwaymentioning

confidence: 99%

See 1 more Smart Citation

Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

Chang

Yin

et al. 2020

Advances in Civil Engineering

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In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.

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Section: Effect Of Mining Stressmentioning

confidence: 99%

Section: Distribution Law Of Mining Stress In Roadwaymentioning

confidence: 99%

Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

Chang

Yin

et al. 2020

Advances in Civil Engineering

View full text Add to dashboard Cite

show abstract

“…At present, the characteristics and laws of the strata behaviors of single-seam mining have been studied. Yin and Han et al studied the stress concentration caused by the mining and structure of the working face from the aspects of theoretical calculation, numerical simulation, and similar material physical simulation technology [12][13][14][15][16]. Ye and Wang et al studied the movement rule and dynamic disturbance of single-seam overburden [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Strong Strata Behaviors in the Close‐Distance Multiseam Coal Pillar Mining

Bao

Song

et al. 2021

Shock and Vibration

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According to the new stress distribution pattern and the strong strata behaviors as the characteristics of the coal pillars in the close-distance multiseam coal pillar mining, the common characteristics of different types of overlying coal pillars were summarized and analyzed. Moreover, a theoretical model for the mechanism of strong strata behaviors in the close-distance multiseam coal pillar mining was established, which was validated by the monitoring data of seismic computed tomography CT, microseism, and electromagnetic radiation (EMR). Furthermore, the results of the study indicated that the main factors affecting the strong strata behaviors were the static stress concentration caused by the overlying coal pillars and the dynamic disturbance caused by the fracturing and slipping of the overlying coal pillars and roof under the influence of mining. In the case of Xinzhouyao coal mine, the transmitted stress and lateral support pressure of the overlying coal pillars accounted for 78.3% and 16% of the vertical concentrated stress, respectively, and the areas closer to the overlying coal pillars were more susceptible to dynamic load disturbances. The monitoring results of seismic computed tomography CT and EMR demonstrated the static load stress concentration area was distributed near the overlying coal pillar, and the stress concentration degree was greater in the area of superimposed lateral support pressure and advanced support pressure. Moreover, microseismic spatial positioning revealed that the high-energy microseismic events were mainly concentrated near the overlying large coal pillars and roof. The on-site multiparameter detection results were highly consistent with the characteristics of actual strata behaviors and the conclusions of the theoretical model. This method could provide a reference for the quantitative calculation of stress distribution under similar conditions and the identification of the danger zone of strata behaviors.

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“…Based on the fracture on key layers, some scholars have used elastic plate theory, 27,28 thin‐plate theory, 29,30 and a Winkler foundation 31 to theoretically investigate the mechanical model of the key layer fracture, established the stiffness and strength conditions of the key layer, the complex key layer model, and the mechanical model of rotational motion about a cantilever beam 32 . With the widespread application of numerical simulation methods, new information about the key layer has been proposed, some scholars have validated the correctness of the six‐movement types of the first subordinate key layer, 33 constructed a mechanical model of the arch structure in the unconsolidated layers, 34 analyzed the working resistance based on the type of movement of the first sub‐key layer in a fully mechanized face with a large‐mining height 35 and found the primary key layer failed by rotational instability 36 .…”

Section: Introductionmentioning

confidence: 99%

The effects of key rock layer fracturing on gas extraction during coal mining over a large height

Xiao

Han

Shuang

et al. 2021

Energy Science & Engineering

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To prevent outbursts and extract the gas, it is necessary to investigate the structure of the key layer and the evolution of cracks during coal mining over a large height. A physical similarity model with a geometric similarity ratio of 1:100 and a strike length of 2 m was established on the basis of prevailing geological and mining conditions. Stress sensors and microseismic equipment were adopted to monitor the collapse characteristics of different key layers through variations in stress and energy. The research results showed that: The displacement of the overlying strata exhibited group motion characteristics marked by the key layer and there was zone of rapidly increasing stress in the goaf behind the working face before and after the fracture of the key layer. Through the analysis of microseismic events, fissure density, and fractal dimension, we found that: before and after the primary key layer fractured, the energy loss in the microseismic event accounted for 27% of the total, the fissure density also changed abruptly from 8 cracks/m to 10 cracks/m and the slope of the fractal dimension curves changed from 0.00243 to 9.94801 × 10−4. Then a gas drainage model suitable for this condition was constructed. When the primary key layer had not fractured, the cracks below fully developed to form a gas migration channel and a gas enrichment area, and gas boreholes could be arranged therein. After the primary key layer had been fractured, the rate of crack development decreased, the permeability would increase, and the gas concentration would increase. The boreholes could still be arranged in the gas migration channel. This study elucidated the control role of the primary key layer from multiple angles and provided experimental guidance for gas drainage over large‐mining heights and during complex key layer mining.

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Method to Calculate Working Surface Abutment Pressure Based on Key Strata Theory

Cited by 25 publications

References 33 publications

Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

Investigation of Strong Strata Behaviors in the Close‐Distance Multiseam Coal Pillar Mining

The effects of key rock layer fracturing on gas extraction during coal mining over a large height

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