Research on Supporting Technology of Wind Drift at B103W01 Workface in ShajiHai Coal Mine

The deformation and failure problems in soft rock supporting cannot be effectively controlled with conventional methods. This paper put forward the coupling support technologies by the use of large deformation constant-resistance bolt, large deformation constant-resistance cable and bottom-grouting pipes, with the analysis of deformation and failure reseasons, combing with verifications in field-test project at B103W01 working face, State Grid Energy abundance Coal Limited Shajihai Coal Mine. It also provides the reference for the tunnels supporting under similar conditions.

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Research on Deformation Mechanisms of a High Geostress Soft Rock Roadway and Double-Shell Grouting Technology

Geofluids ◽

10.1155/2021/6215959 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Fengnian Wang ◽

Shizhuang Chen ◽

Pan Gao ◽

Zhibiao Guo ◽

Zhigang Tao

Keyword(s):

Mechanical Properties ◽

Rock Mass ◽

Large Deformation ◽

Coal Mine ◽

Soft Rock ◽

In Situ Stress ◽

Deformation Monitoring ◽

Deformation And Failure ◽

Working Face ◽

High Geostress

In this study, the deformation characteristics and mechanical properties of coal and rock mass in the S2N5 working face of the Xiaokang coal mine are analyzed to address the problem of large deformation of soft rocks with high in situ stress surrounding roadways. Through a newly developed grouting pipe, a double-shell grouting technology, consisting of low-pressure grouting and high-pressure split grouting, is proposed for the Xiaokang coal mine. In addition, the effect of grouting is evaluated by borehole peeping and deformation monitoring. The results show that the double-shell grouting technology can effectively improve the overall mechanical properties of the surrounding coal and rock mass, preventing the large deformation and failure of the roadway. This technology can be useful when analyzing and preventing large deformation of soft rock roadways.

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Research on Supporting Countermeasure of B103W01 Transport Roadway in Shajihai Coal Mine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.401-403.2221 ◽

2013 ◽

Vol 401-403 ◽

pp. 2221-2225

Author(s):

Shu Jiang Zhao

Keyword(s):

Coal Mine ◽

Deformation Mechanism ◽

Soft Rock ◽

Single Type ◽

Engineering Practice ◽

Deformation And Failure ◽

Constant Resistance ◽

Supporting Effect ◽

Deformation Mechanics ◽

Coupling Support

For the soft rock roadwaysupporting problems, using the conventional methods cannot effectively controlthe deformation and failure. This paper took B103W01 transport gateway projectin Shajihai coal mine as example and analyzed its deformation failure reasonand deformation mechanism and determined the specific measures of transformingcompound mechanism of deformation mechanics into a single type. In the end, weput forward coupling support technology of constant resistance and largedeformation bolt + hollow grouting anchor + corner grouting steel pipe, whichhad been applied to engineering practice. The monitoring results showed thatthe supporting effect was good. So it can be used for reference for the similarconditions of roadway supporting.

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Nonlinear Large Deformation Mechanism and Stability Control of Deep Soft Rock Roadway: A Case Study in China

Sustainability ◽

10.3390/su11226243 ◽

2019 ◽

Vol 11 (22) ◽

pp. 6243 ◽

Cited By ~ 4

Author(s):

Dong Wang ◽

Yujing Jiang ◽

Xiaoming Sun ◽

Hengjie Luan ◽

Hui Zhang

Keyword(s):

Large Deformation ◽

Coal Mine ◽

Deformation Mechanism ◽

Soft Rock ◽

Stability Control ◽

Surrounding Rock ◽

Gansu Province ◽

Soft Rock Roadway ◽

Coupling Support ◽

Rock Roadway

Improving the safety and stability of soft surrounding rock with nonlinear large deformation gives a strong guarantee for the safe mining and sustainable development of deep coal mines. In order to control the nonlinear large deformation of the surrounding rock in a deep soft rock roadway, this paper discusses the nonlinear large deformation mechanism and coupling support countermeasures of a typical engineering application at Xin’an coal mine in Gansu province, China. The series of experiments and theoretical analysis described in this paper reveal the phenomena, properties, and reasons for the nonlinear large deformation of soft surrounding rock in detail. Then, the type of nonlinear large deformation mechanism is determined and transformed from a composite one to a simple one. Based on experimental results and mechanism transformation, a suitable coupling support countermeasure, which contains the Constant Resistance Large Deformation (CRLD) bolt, steel mesh, floor hollow grouting cable, and steel fiber concrete, is proposed to reduce the nonlinear large deformation and the potential risk during mining. The application shows that the coupling support countermeasure can effectively reduce the nonlinear large deformation of the surrounding rock and help to maintain the stability of the deep soft rock roadway at Xin’an coal mine.

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Study on Stability for Intersection of Deep Soft Rock Roadway

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.2666 ◽

2011 ◽

Vol 243-249 ◽

pp. 2666-2669

Author(s):

Zhan Jin Li ◽

Yang Zhang ◽

Xue Li Zhao

Keyword(s):

Coal Mine ◽

Soft Rock ◽

Intersection Problem ◽

The Third ◽

Geological Conditions ◽

Control Stability ◽

Soft Rock Roadway ◽

Crossing Point ◽

Coupling Support ◽

Rock Roadway

With the depth increasing continuously, more complicated of geological conditions, will make intersection in deep soft rock roadway is very difficult to support. In order to solve the intersection problem of difficult to support, combined with the third levels of the Fifth Coal Mine of Hemei, the coupling supporting design—anchor-mesh-cable + truss to control stability of crossing point—is proposed. Based software of FLAC3D, simulate the program applicable in deep soft rock roadway intersection. Application results show that the coupling support technology of anchor-mesh-cable + truss can effectively control the deformation of intersection in deep soft rock roadway.

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Application of Constant Resistance and Large Deformation Anchor Cable in Soft Rock Highway Tunnel

Advances in Civil Engineering ◽

10.1155/2019/4347302 ◽

2019 ◽

Vol 2019 ◽

pp. 1-19 ◽

Cited By ~ 4

Author(s):

Xiaoming Sun ◽

Bo Zhang ◽

Li Gan ◽

Zhigang Tao ◽

Chengwei Zhao

Keyword(s):

Large Deformation ◽

Support System ◽

Field Tests ◽

Soft Rock ◽

Internal Force ◽

Surrounding Rock ◽

Gansu Province ◽

Tunnel Engineering ◽

Anchor Cable ◽

Constant Resistance

Muzhailing Highway Extra-long Tunnel in Lanzhou, Gansu Province, China, belongs to the soft rock tunnel in the extremely high geostress area. During the construction process, large deformation of the soft rock occurred frequently. Taking the no. 2 inclined shaft of Muzhailing tunnel as the research object, an NPR (negative Poisson’s ratio) constant resistance and large deformation anchor cable support system based on high prestress force, constant resistance, and releasing surrounding rock pressure was proposed. The characteristics of the surrounding rock under the steel arch support and NPR anchor cable support were compared and analyzed by using 3DEC software. A series of field tests were conducted in the no. 2 inclined shaft, and the rock strength, displacement of the surrounding rock, deep displacement of the surrounding rock, internal force of steel arch, and axial force of anchor cable were measured to study the application effect of the NPR anchor cable support system in tunnel engineering. Moreover, the 3DEC numerical simulation results were compared with the field test results. The research results show that the application of NPR constant resistance and large deformation anchor cable support system in tunnel engineering has achieved good results, and it plays a significant role in controlling the large deformation of the tunnel surrounding rock.

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Presplitting Blasting the Roof Strata to Control Large Deformation in the Deep Mine Roadway

Advances in Civil Engineering ◽

10.1155/2020/8886991 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Chaowen Hu ◽

Xiaojie Yang ◽

Ruifeng Huang ◽

Xingen Ma

Keyword(s):

Large Deformation ◽

Field Tests ◽

Soft Rock ◽

Surrounding Rock ◽

Deep Mine ◽

Mining Depth ◽

Working Face ◽

Support Conditions ◽

Mine Roadways ◽

Roof Strata

As the mining depth increases, under the influence of high ground stress, the surrounding rock of deep mine roadways shows soft rock characteristics. Under the influence of mining disturbance at the working face, large deformation of the roadway has occurred. To control the large deformation of the roadway, many mines have adopted the form of combined support, which has continuously increased the support strength and achieved a certain effect. However, since the stress environment of the surrounding rock of the roadway has not been changed, large deformation of the roadway still occurs in many cases. Based on the theoretical basis of academician Manchao He’s “short cantilever beam by roof cutting,” this paper puts forward the plan of “presplitting blasting + combined support” to control the large deformation of the deep mine roadways. Without changing the original support conditions of the roadway, presplitting blasting the roof strata of the roadway, by cutting off the mechanical connection of the roof strata between the roadway and gob, improves the stress distribution of the roadway to control the large deformation. Through field tests, the results show that after presplitting blasting the roadway roof, the roadway roof subsidence is reduced by 47.9%, the ribs displacement is reduced by 45.7%, and the floor heave volume is reduced by 50.8%. The effect is significant.

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Comprehensive Measurement of the Deformation and Failure of Floor Rocks: A Case Study of the Xinglongzhuang Coal Mine

Geofluids ◽

10.1155/2020/8830217 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Hao Liu ◽

Pu Wang ◽

Weihe Zhang ◽

Qiang Liu ◽

Lijun Su

Keyword(s):

Coal Mine ◽

Abutment Pressure ◽

Three Dimensional ◽

Strain Sensing ◽

Floor Rock ◽

Deformation And Failure ◽

Working Face ◽

Floor Failure ◽

Coal Wall ◽

Different Depths

The isolated island panel 10304 of the Xinglongzhuang coal mine was used as the research subject to study the deformation and damage characteristics of the coal seam floor. The damage of the floor was studied using the borehole strain sensing method and borehole imaging technology, and FLAC3D was used to study the influence of abutment pressure on floor failure. The result shows that the floor under the superimposed area which is affected by lateral and advanced abutment pressure is damaged firstly, and the maximum depth reaches 26 m, other areas of the working face about 23 m. The degree of deformation and failure of floor rock at different depths is decreased. The deformation damage increases with the advancement of the working face until a certain distance at the same depth. The hole image can clearly show the influence range of the abutment pressure in front of the coal wall and influence the degree of the advancement and lag by means of the strain increment curve for each sensor probe and the images from different drilled positions. On the basis that the results of simulation and field measurement are consistent, the results can reflect the three-dimensional failure characteristics of the whole island working face floor in the process of coal mining more comprehensively and accurately; moreover, they also can provide important information for mine flood prevention and ecological environment protection.

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A Study of Soft Rock Roadway Coupling Support in Xiajing Coal Mine

Procedia Engineering ◽

10.1016/j.proeng.2014.10.500 ◽

2014 ◽

Vol 84 ◽

pp. 812-817

Author(s):

Li Xuefeng ◽

Cheng Guihai ◽

Li Xiaoquan ◽

Zhang Ruichong

Keyword(s):

Coal Mine ◽

Soft Rock ◽

Soft Rock Roadway ◽

Coupling Support ◽

Rock Roadway

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Bolt-Grouting Support in Soft Rock Chamber of Coal Mine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.732 ◽

2013 ◽

Vol 734-737 ◽

pp. 732-736

Author(s):

Hua Wen Lv

Keyword(s):

Large Deformation ◽

Coal Mine ◽

Soft Rock ◽

Stability Control ◽

Rock Stratum

The soft rock stratum, possessing the characteristics of poor anchorage and large deformation, is frequently encountered in underground coal excavation where stability of the whole mining structure is always affected by the soft rock. Therefore, the bolt-grouting support technology in pursuit of an effective way for stability control of soft rock chamber of coal mine in china is conducted. Meanwhile, strata behaviors monitoring is carried out in the chamber to verify effect of bolt-grouting support. The results demonstrate that bolt-grouting goes well in soft rock chamber support.

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