Mechanism of rock burst caused by fracture of key strata during irregular working face mining and its prevention methods

Yang, Zeng-qiang; Liu, Chang; Zhu, Hexuan; Xie, Fuxing; Li, Dou; Chen, Jianhang

doi:10.1016/j.ijmst.2018.07.005

Cited by 65 publications

(32 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prevention and Control by Separating Grouting and Filling e concentrated area or source develops and evolves under deep well superthick conglomerate, and rock burst is caused by the violent activities of the main key strata. e bending, breaking, or stress of the overlying main key strata plays a very important role in the occurrence of rock burst [17][18][19][20].…”

Section: Study On Mechanism Of Rock Burstmentioning

confidence: 99%

A Pocket Assay Grouting Technology for Rock Burst Control under Huge-Thick Conglomerate

Shi

Meng

et al. 2020

Shock and Vibration

View full text Add to dashboard Cite

As the carrier of force and energy, large-scale breaking or bending of huge-thick conglomerate tends to induce impact ground pressure in stope and tunnel. The stratum movement under huge-thick conglomerate was studied in this paper, which is mainly based on the key stratum theory for ground control. Based on this theory, the huge-thick conglomerate can be regarded as the main key stratum, and stratum movement or the development of grassroots state under huge-thick conglomerate will affect the structure itself, which may induce rock burst in stope and tunnel. The grouting technology is proved to effectively limit the bending settlement of conglomerate, control stress concentration of conglomerate, and improve the structure of the source of rock burst, which is an effective method for the control of huge-thick conglomerate. In this paper, the optimization of grouting filling material ratio is studied by the orthogonal experiments and the results show that the optimization of material ratio is cement: fly ash: gangue 1 : 2.22 : 4.44, concentration 75%. Under such conditions, pumpability and intensity reach the best. Meanwhile, a new technology, called pocket assay grouting technology, is put forward in this paper. It can prevent slurry leakage, protect the environment, and improve the efficiency of slip casting. The application of this technology in Huafeng mine shows that it not only realizes the safe, efficient, and green of coal mine but also provides technical support to control occurrence of rock burst induced by the movement of the huge-thick conglomerate in deep mining.

show abstract

Section: Study On Mechanism Of Rock Burstmentioning

confidence: 99%

A Pocket Assay Grouting Technology for Rock Burst Control under Huge-Thick Conglomerate

Shi

Meng

et al. 2020

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…Faults are the most common geological structures in coal mining. e rockburst induced by fault activation belongs to structural instability disaster and has the following characteristics: the large burst amount of coal rock, strong destruction, rapid occurrence, and unclear precursor information [19][20][21][22][23]. In recent years, research on fault rockburst has been widely performed.…”

Section: Introductionmentioning

confidence: 99%

The Mechanical Criterion of Activation and Instability of Normal Fault Induced by the Movement of Key Stratum and Its Disaster‐Causing Mechanism of Rockburst in the Hanging Wall Mining

Pengfei

Jiabin

Wang

et al. 2021

Advances in Civil Engineering

View full text Add to dashboard Cite

Coal mine rockburst is closely related to the complex geological structure. Understanding the criterion of the fault activation instability and the disaster-causing mechanism of rockburst under the influence of mining is the theoretical premise and important guarantee of safe and efficient coal mining. In this paper, based on the theory of key stratum, the mechanical model of fault slip instability in the normal fault during the hanging wall mining was established, and the instability criterion was derived. It is concluded that the fault slip instability of the hanging wall is mainly controlled by two factors: (1) the distance between coal seams and key stratum and (2) the distance between working face and fault. Moreover, these two factors have an inverse relation to the occurrence of rockburst. Subsequently, three conceptual models of rockburst induced by the fault stress transfer, stress concentration of coal pillars, and fault structural instability were proposed. Based on the rock mechanics theory, the rockburst carrier system model of “roof-coal seam-floor” near the fault was established. The mechanical essence of fault rockburst was obtained as follows: under the action of fault, the static load of fault coal pillar was increased and superimposed with the fault activation dynamic load, leading to high-strength rockburst disaster. Based on the occurrence mechanism of fault rockburst, the monitoring and prevention concept and technical measures were proposed in three aspects, including the monitoring and control of fault activation dynamic loads, the monitoring of high static load in fault coal pillar and stress release, and the strengthening roadway support. These prevention and control measures were verified in the panel 103down02 of the Baodian Coal Mine in engineering, and the effectiveness of these measures was proved.

show abstract

“…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

View full text Add to dashboard Cite

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.

show abstract

Mechanism of rock burst caused by fracture of key strata during irregular working face mining and its prevention methods

Cited by 65 publications

References 2 publications

A Pocket Assay Grouting Technology for Rock Burst Control under Huge-Thick Conglomerate

A Pocket Assay Grouting Technology for Rock Burst Control under Huge-Thick Conglomerate

The Mechanical Criterion of Activation and Instability of Normal Fault Induced by the Movement of Key Stratum and Its Disaster‐Causing Mechanism of Rockburst in the Hanging Wall Mining

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

Contact Info

Product

Resources

About