The fracture mechanism and acoustic emission analysis of hard roof: a physical modeling study

Li, Nan; Wang, Enyuan; Ge, Mao Chen; Liu, Jie

doi:10.1007/s12517-014-1378-y

Cited by 45 publications

(14 citation statements)

References 10 publications

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“…The technologies of hydraulic fracturing to weaken hard roofs in advance have been gradually accepted in coal mines of China recently [54][55][56]. In mining engineering, there are two requirements for the application of the proposed mining-induced failure criteria: (1) There is a soft layer being sandwiched between the two interactional hard roof structures; (2) the equilibrium condition of structures should satisfy Equations (6), (13), and (14). Further, correlative parameters of IHRS need to be re-determined considering the varying geological conditions.…”

Section: Discussionmentioning

confidence: 99%

“…To effectively control the deformation of tail entry in the strong mining pressure zone, it is important to understand the mechanical behavior of the hard roof structures above the side of Gob 1 during retreat of the mining working face of Panel 2. Mechanical behavior of hard roof structures mainly refers to the separation, fracture, rotation, slipping, and yielding when the stress reaches the strength of structures [9][10][11][12][13][14][15][16][17]. At present, stability analyses of mechanical behavior are mainly concentrated on the single structure in one layer.…”

Section: Introductionmentioning

confidence: 99%

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Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

et al. 2019

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Due to the additional abutment stress, interactional hard roof structures (IHRS) affect the normal operation of the coal production system in underground mining. The movement of IHRS may result in security problems, such as the failure of supporting body, large deformation, and even roof caving for nearby openings. According to the physical configuration and loading conditions of IHRS in a simple two-dimensional physical model under the plane stress condition, mining-induced failure criteria were proposed and validated by the mechanical behavior of IHRS in a mechanical analysis model. The results indicate that IHRS, consisting of three interactional parts-the lower key structure, the middle soft interlayer, and the upper key structure-are governed by the additional abutment stress induced by the longwall mining working face. The fracture of the upper key structure in IHRS can be explained as follows: Due to the crushing failure, lower key structure, and middle soft interlayer yield, the action force between the upper and lower key structures vanishes, resulting in fracture of the upper key structure in IHRS. In a field case, when additional abutment stress reaches 7.37 MPa, the energy of 2.35 × 10 5 J is generated by the fracture of the upper key structure in IHRS. Under the same geological and engineering conditions, the energy generated by IHRS is much larger than that generated by a single hard roof. The mining-induced failure criteria are successfully applied in a field case. The in-situ mechanical behavior of the openings nearby IHRS under the mining abutment stress can be clearly explained by the proposed criteria.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

et al. 2019

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“…7 In recent years, many mining science and technology workers have researched the control mechanisms and technologies of roadway surrounding rock under complex geological conditions such as large sections, soft surrounding rocks, and composite roofs. [8][9][10][11][12][13][14][15][16][17][18] To control the surrounding rock of a large section of a roadway, Xie et al 19 studied the failure mechanisms of a large section of a chamber under a 1200-m deep goaf and proposed a comprehensive control technology. Hao et al 20 applied an innovative equivalent width support technology for a large section of roadway in a thick coal seam based on a theoretical analysis, experiments, and applications.…”

Section: Introductionmentioning

confidence: 99%

Combined support technology for main roadway passing through goaf: A case study

Chen

Zhang

Xie

et al. 2020

Energy Science & Engineering

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“…The characteristics of AE signals in the process of hard roof failure show that in a short period of time before the failure of hard roof, the AE count shows an upward trend, and the AE energy increases sharply. These signals reach the peak value when the rock is broken and then decrease rapidly, ending at a weak level, which can provide certain ideas and references for predicting and monitoring the rock burst caused by the failure of Hard Roof [16]. The method of active seismic velocity inversion is used to predict the rock burst hazard of the long wall face of the island, which has made remarkable achievements in the disaster prevention and control of the rock burst mine [17].…”

Section: Introductionmentioning

confidence: 99%

Study on Rule of Overburden Failure and Rock Burst Hazard under Repeated Mining in Fully Mechanized Top-Coal Caving Face with Hard Roof

et al. 2019

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The dynamic disasters caused by the failure of hard roof in the process of mining coal seriously affect the safe production in coal mines. Based on the W1123 mining coal working face of Kuangou coal mine, the physical similar material simulation experiment and acoustic emission (AE) monitoring method are used to study the failure law and AE characteristics of overburden in the process of coal mining. The stress evolution law is revealed through numerical simulation, the dangerous areas and rock burst hazard under the repeated mining with hard roof are studied combined with microseismic monitoring on site. The results show that the energy of W1123 working face released by the overburden damage under B4-1 solid coal is higher than that of the gob, and the peak value of the AE energy appears near the W1145 open-off cut. Through the statistics of the AE data, the large energy rate of AE event is defined, and the AE events with large energy rate appear in the scale of 82.4–231.2 cm within the model. This area is shown as a stress superposition area according to the numerical simulation. On the basis of comparing with the characteristics of energy distribution in the field, it is considered that the main control factors of rock burst in this area are hard roof of the working face and the stress concentration caused by the repeated mining. It provides a scientific guidance for the prevention and control measures of rock burst in this type of mining condition.

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The fracture mechanism and acoustic emission analysis of hard roof: a physical modeling study

Cited by 45 publications

References 10 publications

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

Combined support technology for main roadway passing through goaf: A case study

Study on Rule of Overburden Failure and Rock Burst Hazard under Repeated Mining in Fully Mechanized Top-Coal Caving Face with Hard Roof

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