Mechanism and technology study of collaborative support with long and short bolts in large-deformation roadways

Yu, Hui; Niu, Zhiyong; Kong, Linggen; Hao, Caicheng; Cao, Peng

doi:10.1016/j.ijmst.2015.05.011

Cited by 16 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Te basis of this code is the fnite diference numerical method with the Lagrangian calculation method. Te fnite diference method (FDM) can be more efectively applied to modelling of stress distribution around an underground roadway in comparison with other numerical techniques [24].…”

Section: Numerical Simulation Methodology and Input Parametersmentioning

confidence: 99%

Numerical Simulation Study on Influence of a Structural Parameter of D Bolt, an Energy-Absorbing Rock Bolt, on its Stress Distribution

Pyon,

Son,

Han

2023

Advances in Civil Engineering

View full text Add to dashboard Cite

A D bolt, an energy-absorbing rock bolt, is a smooth steel bar with a number of anchors along its length. The anchors, which can be spaced evenly or unevenly along its length, are firmly fixed within a borehole using either cement grout or resin, while the smooth sections of the bolt between the anchors may freely deform in response to rock dilation. A series of numerical simulations have been conducted using the finite difference method to investigate the effects of D bolt on the displacement increase of rock mass around a roadway in comparison with normal fully encapsulated rebar. As a result, the displacement of 49 mm at the top of roadway roof in the D bolts supported model is much larger than 30.08 mm in the fully encapsulated rebar bolts supported model so that the former is capable of absorbing potential deformation energy of rock mass around a roadway to tolerate the large deformation of rock. Plans of spacing arrangement of D bolt’s anchor have a significant effect on stress redistribution of the bolt. The numerical simulation result shows that for the D bolt with its whole length of 2.4 m, the length of its exposed section of 0.1 m, and the 4 anchors with the length of 0.1 m, the maximum tensile stress of 3.25 GPa generated in the D bolt with the ratio of the spacing between anchors (RSA) of 30 : 40 : 50 : 70 is lower about 1.13–1.31 times than the other D bolts with different ratio of spacing, and the changing range of stress is also the smallest, where the ratio of 30 : 40 : 50 : 70 indicates a ratio of lengths of deformable sections which is determined by turns from the innermost section of rock mass around roadway to the outermost section of roadway space. This study demonstrates that it is reasonable to employ the RSA of D bolt which makes it bring out its energy-absorbing capability to the full.

show abstract

Section: Numerical Simulation Methodology and Input Parametersmentioning

confidence: 99%

Numerical Simulation Study on Influence of a Structural Parameter of D Bolt, an Energy-Absorbing Rock Bolt, on its Stress Distribution

Pyon,

Son,

Han

2023

Advances in Civil Engineering

View full text Add to dashboard Cite

show abstract

“…e area remains stable because of the combined effect of shields, rock bolts, and cables. Bolts and cables with different lengths act on different areas and play different roles [20]. e failure characteristics of surrounding rock present different states due to different supporting methods.…”

Section: Failure Characteristics Of Roof and Its Formation Processmentioning

confidence: 99%

Stability Mechanism and Control Factors on Equipment Removal Area under “Goaf‐Roof‐Coal” Structure

Chen

Yuan

Zhu

et al. 2021

Advances in Civil Engineering

View full text Add to dashboard Cite

One of the main difficulties in longwall mining (LM) is the movement of mining equipment from one panel to the next panel during mining process. The shields of the LM face may be damaged by the collapse of the roof in shallow coal seam under the “Goaf-Roof-Coal” (GRC) structure, especially when moving the shields from the current panel to the next panel. In order to solve this problem, the stability mechanism and its control factors during the LM equipment removal were investigated by using comprehensive methods including theoretical analysis, numerical simulation, and field validation based on the working conditions of Panel 31102 in Liangshuijing Coal Mine. The numerical simulations demonstrate that four different failure zones, shear failure zone, tension failure zone, partly elastic zone, and plastic failure zone, appear around the area due to the position of rock and the arrangements of the supports. The shear failure zone, which is controlled by shield working resistance and roof supporting strength, is the main cause of the failure in the removal area. To minimize the shear failure zone, several measures such as optimizing the end position for LM face, decreasing the width of removal area, and increasing the amount of cable support were taken to ensure the stability of surrounding rock in removal area, which have successfully controlled the damage of roof and equipment in Panel 31102. The field observation confirms that the proposed stability mechanism and control measures are effective under GRC structure.

show abstract

“…Also, when used as a false roof, they allow the hydraulic support to hold the wood pile or filling body above when the roof collapses, so that there is no empty roof above the support. The supporting effect is relatively excellent [22][23][24][25]. 8 Geofluids…”

Section: Reinforcement Measures For the Weak Roof In Thementioning

confidence: 99%

Surrounding Rock Control Technology When the Longwall Face Crosses Abandoned Roadways: A Case Study

et al. 2021

View full text Add to dashboard Cite

When a working face is crossing the abandoned roadways, problems such as roof subsidence, rock fracture, and instability will occur, resulting in widespread roof fall and rib spalling, which seriously affect safe and efficient mining on the working face. In this paper, the no. 23 coal pillar working face of Juji coal mine is taken as the engineering background, a mechanical model of crossing the abandoned roadways is constructed aimed at the problem of the working face crossing the abandoned roadway group, the collapse of the abandoned roadway roof is analyzed, a scheme of crossing the abandoned roadways is designed, and the development law of the stress and plastic zone after the reinforcement scheme is stimulated and analyzed. The results show that when the working face advances to the abandoned roadway, key block B crosses the abandoned roadway and the solid coal to form a “cross-roadway long key block.” It is calculated that the minimum support resistance required for the abandoned roadway is 6700 kN. Based on the results of numerical comparison, it is concluded that filling wood pile when the working face passes through the roof abandoned roadway and adding anchor cables for reinforcement support when the working face crosses the coal seam abandoned roadway effectively reduce the stress concentration of surrounding rocks, decrease the development of the plastic zone, and achieve safe and efficient mining when the working face crosses the abandoned roadways.

show abstract

Mechanism and technology study of collaborative support with long and short bolts in large-deformation roadways

Cited by 16 publications

References 10 publications

Numerical Simulation Study on Influence of a Structural Parameter of D Bolt, an Energy-Absorbing Rock Bolt, on its Stress Distribution

Numerical Simulation Study on Influence of a Structural Parameter of D Bolt, an Energy-Absorbing Rock Bolt, on its Stress Distribution

Stability Mechanism and Control Factors on Equipment Removal Area under “Goaf‐Roof‐Coal” Structure

Surrounding Rock Control Technology When the Longwall Face Crosses Abandoned Roadways: A Case Study

Contact Info

Product

Resources

About