Feasibility analysis of gob-side entry retaining on a working face in a steep coal seam

Deng, Yangfan; Shouquan, Wang

doi:10.1016/j.ijmst.2014.05.013

Cited by 45 publications

(25 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Currently, research on gob-side entry retaining by backfilling is mainly focused on the deformation characteristics of entry surrounding rocks [5][6][7][8][9][10][11][12], stability control technology [13][14][15][16], parameter determination of backfilling bodies [17][18][19], etc. Some representative research achievements are summarized as follows:…”

Section: Introductionmentioning

confidence: 99%

“…(a) Deformation characteristics of roof strata Deng and Wang (2014) and Zhang et al (2014) [5,6] analyzed roof deformation, failure laws, and roadway support technology of gob-side entry retaining in a thin seam with a large inclined angle. Li et al (2015), Wang et al (2001), Gao et al (2000), and Lu et al (2011) [7][8][9][10] established a mechanical model related to the immediate roof of the entry using elastoplastic mechanics theory and obtained deformation characteristics under the effects of a given deformation of the upper main roof.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Roof Deformation Characteristics and Preventive Techniques Using a Novel Non-Pillar Mining Method of Gob-Side Entry Retaining by Roof Cutting

et al. 2018

View full text Add to dashboard Cite

Abstract:A new non-pillar mining technology, gob-side entry retaining by roof cutting (GERRC), different from the conventional gob-side entry retaining formed by a roadside filling support, is introduced in this study. In the new technology, roof cutting is conducted so that the roof plate forms a short cantilever beam structure within a certain range above the retained entry, thus changing the stress boundary condition of the roof structure. To explore the deformation characteristics of the roof under this special condition, a short cantilever beam mechanical model was established and solved using energy theory and displacement variational methods. Meanwhile, a theoretical and analytical control solution for roof deformation was obtained and verified via field-measured results. Based on the aforementioned calculation, the relationship between the roof deformation and main influence parameters was explored. It was concluded that the rotation of the upper main roof and width of the retained entry had the most significant impacts on roof deformation. Bolt and cable support and temporary support in the entry had a non-obvious influence on the roof deformation and could not prevent the given deformation that was caused by the rotation of the upper main roof. Based on comprehensive theoretical analysis and calculation results, ideas and countermeasures to control short cantilever roof deformation-that is, designing a reasonable height of roof cutting and a controlled width of retaining entry-were proposed and tested. Field monitoring shows that the entry control effects were satisfactory.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Roof Deformation Characteristics and Preventive Techniques Using a Novel Non-Pillar Mining Method of Gob-Side Entry Retaining by Roof Cutting

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In recent decades, many studies have been conducted on the stability control of the RGSG. Examples of such studies can be briefly generalized as follows: design principles, high-water material [7][8][9]; the controlling methods of the stability of the RGSG packfillings, roof and sidewalls were researched in a backfilling mining system, inclined coal seam in 2010, 2011, 2013, and 2014 [10][11][12][13]; and the construction methods of the RGSG packfillings under hard roof strata, composed roof strata, and soft roof strata was studied in 2015, 2016, and 2017 [14][15][16]. The roof and sidewalls of the RGSG were maintained within acceptable limits according to the aforementioned advanced supporting theory and techniques.…”

Section: Deformations Of the Rgsgmentioning

confidence: 99%

Numerical Study on the Effectiveness of Grouting Reinforcement on the Large Heaving Floor of the Deep Retained Goaf-Side Gateroad: A Case Study in China

Zhang

Shimada

2018

Energies

View full text Add to dashboard Cite

Abstract:To study the effectiveness of grouting reinforcement on a large heaving floor of the retained goaf-side gateroad (RGSG) at a 900 m depth in the Zhuji coal mine, a numerical model involving strain softening constitutive material was built. First, the simulated deformations of the RGSG were compared with field data to verify the reliability of the numerical model. Then, the dynamic distribution of the stress in the RGSG floor was examined to reveal the mechanism of floor heave. Finally, grouting reinforcement was proposed to control the RGSG floor, and the corresponding effectiveness was verified by improving the rock mechanics of the floor strata based on the results of numerical uniaxial compressive tests. The results demonstrated that a fairly good match was achieved between the field and numerical data, and the proposed FLAC3D (Fast Lagrangian Analysis of Continua) numerical model was an effective approach to study the stability of the deep RGSG. A variation of the ratio between horizontal stress to vertical stress in the floor strata was the root cause of floor heave in the deep RGSG. Ideally, the floor heave could be reduced by 41%, 62%, and 79% when the floor strata of 1 m depth were reinforced with grouting schemes I, II, and III, respectively.

show abstract

“…The mining of TCS not only meets requirements of sustainable development but also has economic and social value on the gas extraction and the recovery rate of coal resources [2]. Entries in TCSs are excavated in mixed coal and rock mass, which decrease excavation speed of roadway and delay the mining plan and exacerbate environmental problems of gangue hills [3]. Gob-side entry retaining (GER), where a roadway of previous panel is retained without coal pillars by constructing a roadside backfill body (RBB) lagging behind the working face along the gob-side, was proposed to solve these problems, as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Key Parameters of Gob-Side Entry Retaining in A Gassy and Thin Coal Seam with Hard Roof

et al. 2018

View full text Add to dashboard Cite

Gob-side entry retaining (GER) employed in a thin coal seam (TCS) can increase economic benefits and coal recovery, as well as mitigate gas concentration in the gob. In accordance with the caving style of a limestone roof, the gas concentration and air pressure in the gob were analyzed, and a roof-cutting mechanical model of GER with a roadside backfill body (RBB) was proposed, to determine the key parameters of the GER-TCS, including the roof-cutting resistance and the width of the RBB. The results show that if the immediate roof height is greater than the seam height, the roof-cutting resistance and width of the RBB should meet the requirement of the immediate roof being totally cut along the gob, for which the optimal roof-cutting resistance and width of RBB were determined by analytical and numerical methods. The greater the RBB width, the greater its roof-cutting resistance. The relationship between the supporting strength of the RBB and the width of the RBB can be derived as a composite curve. The floor heave of GER increases with increasing RBB width. When the width of the RBB increased from 0.8 m to 1.2 m, the floor heave increased two-fold to 146.2 mm. GER was applied in a TCS with a limestone roof of 5 m thickness; the field-measured data verified the conclusions of the numerical model.

show abstract

Feasibility analysis of gob-side entry retaining on a working face in a steep coal seam

Cited by 45 publications

References 6 publications

Roof Deformation Characteristics and Preventive Techniques Using a Novel Non-Pillar Mining Method of Gob-Side Entry Retaining by Roof Cutting

Roof Deformation Characteristics and Preventive Techniques Using a Novel Non-Pillar Mining Method of Gob-Side Entry Retaining by Roof Cutting

Numerical Study on the Effectiveness of Grouting Reinforcement on the Large Heaving Floor of the Deep Retained Goaf-Side Gateroad: A Case Study in China

Key Parameters of Gob-Side Entry Retaining in A Gassy and Thin Coal Seam with Hard Roof

Contact Info

Product

Resources

About