Numerical Analysis of Longwall Gate-Entry Stability under Weak Geological Condition: A Case Study of an Indonesian Coal Mine

Sasaoka, Takashi; Mao, Pisith; Shimada, Hideki; Hamanaka, Akihiro; Oya, Jiro

doi:10.3390/en13184710

Cited by 11 publications

(10 citation statements)

References 23 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The range of stress ratio is vary based on the location. Generally, for 300 m depth, it is around 0.5 to 2 [23][24][25]41]. For the studied site, the range of stress ratio is assumed to be from 0.5 to 2.…”

Section: Global Model Descriptionmentioning

confidence: 99%

“…The longwall face is supported by powered shield support. The detail of goaf modeling is explained by Sasaoka, et al [25]. Since roof caving occurs in the goaf area which makes the whole area inaccessible, it is very difficult to study and obtain goaf behavior.…”

Section: Global Model Descriptionmentioning

confidence: 99%

“…Weak geological conditions have proven to impose many challenges in the development of longwall mining [20][21][22]. The lack of rock strength competence requires its own investigation of its rock mass, strata behavior, stress distribution, deformation, and exclusive support design during mine development and operation [21][22][23][24][25]. A big portion of the global coal reserves is located in weak geological conditions [26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Investigation of Roof Stability in Longwall Face Developed in Shallow Depth under Weak Geological Conditions

et al. 2022

Self Cite

View full text Add to dashboard Cite

Developing longwall mining under weak geological conditions imposes a substantial challenge with regard to the higher risk of falling roofs. Maintaining the stability of the longwall face in this aforementioned condition is crucial for smooth operation. Investigating roof conditions in longwall requires detailed study of rock behavior in response to a few key influences. This paper presents the outcome of a numerical analysis of roof stability in shallow depth longwall face under weak geological conditions. A series of validated FLAC3D models was developed to examine the roof condition of the longwall face under the influence of shield canopy ratio, shield resistance force, and stress ratio. The results show that these three key factors have a significant impact on longwall roof conditions, which can be used to optimize its stability. Two distinct mechanisms of the roof caving behavior can be observed under the influence of stress ratio. The countermeasures of reducing face-to-tip distance and cutting width are proposed to improve the roof condition of longwall face under weak rock. The outcomes show a substantial improvement in roof conditions after adopting the proposed method.

show abstract

Section: Global Model Descriptionmentioning

confidence: 99%

Section: Global Model Descriptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Investigation of Roof Stability in Longwall Face Developed in Shallow Depth under Weak Geological Conditions

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…The occurrence of roof falls in longwalls, apart from posing a danger to the working personnel, also has a negative impact on the efficiency of the entire hard coal mine. This relates both to a limitation of the daily progress of the longwall and to the incorrect operation of the powered longwall system elements, in particular, the powered roof supports constituting the basic protection of the longwall face [5,[8][9][10][11][12]. Three forms of loss of stability of the longwall working can be distinguished, i.e., minor roof fall, medium roof fall and major roof fall as shown in Figure 1 [1,5,8,13,14].…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of the Impact of Unmined Longwall Panel on the Working Stability of a Longwall Using UDEC 2D—A Case Study

et al. 2022

View full text Add to dashboard Cite

The main goal of the paper is numerical simulation for investigation of damage causes in the working of a longwall located under the unmined longwall panel. The paper presents the results of model-based research on the stability of the roof of a longwall working in a zone subject to cave-in mining, taking into account the influence of mining conditions in the form of an unmined coal seam located 115 m above the exploited seam. It presents the geometry of the rock mass under study, the discretization area of the solution, and gives an overview of the assumptions used to build the numerical model. The authors discuss the results of numerical simulations of the influence of mining phenomena on the formation of roof falls in the longwall. Based on the results of numerical simulations, the process of identifying the size of roof falls in a longwall working (loss of stability) was carried out through their appropriate classification. The case presented and analyzed in this paper occurred in one of Poland’s coal mines.

show abstract

“…The drum is the main working part of the coal shearer, and its performance directly affects the mining efficiency of shearer (Luo et al., 2015; Sasaoka, 2020). As the cutting mechanism of the coal shearer, the drum cuts the coal seam and peels off the coal block, and uses the helix blade to transport the coal piece into the scraper conveyor, but due to the constraints of the working environment and the structure of the drum, the performance of the drum is poor.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation on coal loading process of shearer drum based on discrete element method

Tian

Jing

Zhao

et al. 2021

Energy Exploration & Exploitation

View full text Add to dashboard Cite

The drum is the working mechanism of the coal shearer, and the coal loading performance of the drum is very important for the efficient and safe production of coal mine. In order to study the coal loading performance of the shearer drum, a discrete element model of coupling the drum and coal wall was established by combining the results of the coal property determination and the discrete element method. The movement of coal particles and the mass distribution in different areas were obtained, and the coal particle velocity and coal loading rate were analyzed under the conditions of different helix angles, rotation speeds, traction speeds and cutting depths. The results show that with the increase of helix angle, the coal loading first increases and then decreases; with the increase of cutting depth and traction speed, the coal loading rate decreases; the increase of rotation speed can improve the coal loading performance of drum to a certain extent. The research results show that the discrete element numerical simulation can accurately reflect the coal loading process of the shearer drum, which provides a more convenient, fast and low-cost method for the structural design of shearer drum and the improvement of coal loading performance.

show abstract

Numerical Analysis of Longwall Gate-Entry Stability under Weak Geological Condition: A Case Study of an Indonesian Coal Mine

Cited by 11 publications

References 23 publications

Numerical Investigation of Roof Stability in Longwall Face Developed in Shallow Depth under Weak Geological Conditions

Numerical Investigation of Roof Stability in Longwall Face Developed in Shallow Depth under Weak Geological Conditions

Numerical Simulation of the Impact of Unmined Longwall Panel on the Working Stability of a Longwall Using UDEC 2D—A Case Study

Numerical simulation on coal loading process of shearer drum based on discrete element method

Contact Info

Product

Resources

About