Study on High Prestressed Anchor Beam Supporting Optimization Technology in Deep Roadway

2013 ◽  
Vol 353-356 ◽  
pp. 1675-1679 ◽  
Author(s):  
Hui Li ◽  
Wen Jiang Liu ◽  
Wei Guo Qiao
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Ground Pressure ◽  
Safety Production ◽  
Original Scheme ◽  
Surrounding Rock Control ◽  
The Stability ◽  
Borehole Televiewer ◽  
Ground Penetrating ◽  
Prestressed Anchor

Coal mine has stepped into deep mining period in China, in which the ground pressure is great, the stability of the surrounding rock is poor and roadway is seriously destroyed. 3302 trick roadway of Zhaolou coal mine is the kilometers depth roadway, under the condition of original supporting, the roof settling amount and the surrounding rock deformation were large, which made bad effect on safety production. The surrounding rock failure region was monitored by borehole televiewer and ground penetrating radar, and the loosening failure law was analyzed. The scheme of high prestressed anchor beam was proposed according to the detection results, the crack distribution of surrounding rock and the stress of blots and anchors of original scheme and optimized scheme were analyzed by UDEC. The results of numerical simulation and field monitoring showed that increasing prestress of blot and anchors was better for the control of roof separation in anchorage zone and maintaining the integrity of roof, and high prestressed anchor beam can effectively improve the effect of surrounding rock control in roadways.

scholarly journals Investigation of Mechanical Properties for Group Anchors

2021 ◽  
Vol 11 (4) ◽  
pp. 1521
Author(s):  
Juncai Cao ◽  
Nong Zhang ◽  
Shanyong Wang ◽  
Qun Wei
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Design Method ◽  
Stability Control ◽  
Surrounding Rock ◽  
Physical Test ◽  
Anchor Structure ◽  
The Stability ◽  
Mine Roadways ◽  
Prestressed Anchor

Prestressed anchor support is one of the most important support methods for coal mine roadways. As the coal mining depth increases, the adaptability of existing prestressed anchor has become weaker and weaker, which is mainly reflected in the current anchor prestress is much smaller than the support resistance required for the stability of the roadways and makes it difficult to effectively control the roadways. In order to solve the problem, a group anchor structure was proposed to realize higher prestressed anchor support technology and improve the support status of deep roadways. For coal mine roadways, group anchor structure is a new technology and new topic, and the design method and theoretical basis of the group anchor support are lacking. Therefore, the paper studied the bearing capacity of the group anchors through physical tests and numerical simulations. Among them, a special set of group anchor drawing tooling was designed and processed to match the physical test. The test results show that the group anchor structure can double the bearing capacity and bearing rigidity compared with traditional anchors, and the group anchor support can further optimize the support parameters to improve the bearing capacity of the surrounding rock. Therefore, the group anchor support is helpful to the stability control of the surrounding rock of the deep roadway.

Nondestructive Test on Typical Roadway Supports of a Mine via Drilling Core and Ground Penetrating Radar

2011 ◽  
Vol 368-373 ◽  
pp. 2411-2416
Author(s):  
Jian Ping Han ◽  
Hai Peng Liu
Keyword(s):  
Ground Penetrating Radar ◽  
Geological Structure ◽  
Surrounding Rock ◽  
Potential Threat ◽  
Real Performance ◽  
Design Requirements ◽  
And Performance ◽  
The Stability ◽  
Ground Penetrating ◽  
Drilling Core

Temporary or permanent supports are necessary in underground construction for maintaining the stability and limiting the damage of surrounding rock. Due to the uncertainty of geological structure, the specificity of the underground environment as well as other factors, the quality and performance of supporting structure are often difficult to satisfy the design requirements, which not only seriously affects the normal construction and operation of mines but also has the potential threat to the safety of underground production. In order to investigate the influence of the unfavorable geologic environment on supporting concrete and evaluate the real performance of roadway supports of a mine, 17 typical projects were chosen and the strength of supporting concrete was detected by nondestructive drilling core method. The result shows that the strength is widely less than the design value. Furthermore, 4 projects of them were investigated by the ground penetrating radar (GPR) in order to evaluate the feasibility of GPR in the performance investigation of the roadway supports of a mine. The results indicate that ground penetrating radar is capable of measuring the thickness of the support, the distribution of rebars and the defects of the surrounding rock.

scholarly journals Study of the Stability Control of the Rock Surrounding Double-Key Strata Recovery Roadways in Shallow Seams

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Cheng Zhu ◽  
Yong Yuan ◽  
Zhongshun Chen ◽  
Zhiheng Liu ◽  
Chaofeng Yuan
Keyword(s):  
Engineering Application ◽  
Stability Control ◽  
Surrounding Rock ◽  
Control Effect ◽  
Pressure Relief ◽  
Support Design ◽  
Key Strata ◽  
Fracture Development ◽  
Surrounding Rock Control ◽  
The Stability

The stability control of the rock surrounding recovery roadways guarantees the safety of the extraction of equipment. Roof falling and support crushing are prone to occur in double-key strata (DKS) faces in shallow seams during the extraction of equipment. Therefore, this paper focuses on the stability control of the rock surrounding DKS recovery roadways by combining field observations, theoretical analysis, and numerical simulations. First, pressure relief technology, which can effectively release the accumulated rock pressure in the roof, is introduced according to the periodic weighting characteristics of DKS roofs. A reasonable application scope and the applicable conditions for pressure relief technology are given. Considering the influence of the eroded area on the roof structure, two roof mechanics models of DKS are established. The calculation results show that the yield load of the support in the eroded area is low. A scheme for strengthening the support with individual hydraulic props is proposed, and then, the support design of the recovery roadway is improved based on the time effects of fracture development. The width of the recovery roadway and supporting parameters is redesigned according to engineering experience. Finally, constitutive models of the support and compacted rock mass in the gob are developed with FLAC3D software to simulate the failure characteristics of the surrounding rock during pressure relief and equipment extraction. The surrounding rock control effects of two support designs and three extraction schemes are comprehensively evaluated. The results show that the surrounding rock control effect of Scheme 1, which combines improved support design and the bidirectional extraction of equipment, is the best. Engineering application results show that Scheme 1 realizes the safe extraction of equipment. The research results can provide a reference and experience for use in the stability control of rock surrounding recovery roadways in shallow seams.

scholarly journals Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Stability Index ◽  
Surrounding Rock ◽  
Full Length ◽  
Control Effect ◽  
Support Design ◽  
Rock Stability ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.

scholarly journals Study on In Situ Stress Measurement and Surrounding Rock Control Technology in Deep Mine

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhongcheng Qin ◽  
Bin Cao ◽  
Yongle Liu ◽  
Tan Li
Keyword(s):  
Stress Field ◽  
Principal Stress ◽  
Coal Mine ◽  
Maximum Principal Stress ◽  
In Situ Stress ◽  
Measured Data ◽  
Surrounding Rock ◽  
In Situ Stress Measurement ◽  
Surrounding Rock Control

In situ stress is the direct cause of roadway deformation and failure in the process of deep mining activities. The measured data of in situ stress in the Shuanghe coal mine show that the maximum principal stress is 44.94~50.61 MPa, and the maximum principal stress direction is near horizontal direction, which belongs to tectonic stress field. The maximum horizontal principal stress is 1.66~1.86 of the vertical stress. The horizontal principal stress controls the deep stress field. According to the measured data of in situ stress, the high-strength prestress bolt and cable collaborative support form is designed in the Shuanghe coal mine. Based on the stress field research of bolt and cable, the optimal prestress ratio of bolt and cable is proposed as 3. When the prestress ratio of bolt and cable is constant, the smaller the length ratio of bolt and cable is, the better the effect of prestressed field formed by cooperative support is. The results are applied to the support design of the mining roadway in the Shuanghe coal mine. Through the field monitoring test results, it is found that the maximum roof subsidence is 86 mm, the maximum floor deformation is 52 mm, and the maximum deformation of two sides is 125 mm. The surrounding rock control effect of the roadway is good, and the surrounding rock deformation conforms to the engineering technology standard requirements. The research results of this paper can provide some reference for the surrounding rock support of high ground stress mining roadway under similar conditions.

Stability and Deformation Analysis for Excavation and Backfilling of Fushun West Open-Pit Coal Mine

2013 ◽  
Vol 353-356 ◽  
pp. 751-755 ◽  
Author(s):  
Yong Cheng Yan ◽  
Xian Zhang Ling ◽  
Feng Zhang ◽  
Jia Hui Wang
Keyword(s):  
Coal Mine ◽  
Slip Surface ◽  
Surrounding Rock ◽  
Open Pit ◽  
Deformation Analysis ◽  
Interface Model ◽  
Safety Coefficient ◽  
Mine Slope ◽  
The Stability ◽  
Technical Basis

Taking section W400 of Fushun west open-pit coal mine for the research, the interface model of fracture zone and surrounding rock was established. FLAC3D is used to analysis the influence of excavation and backfill of open-fit coal mine to the slope stability and deformation. The numerical results and analysis show that: (1) when the open-pit coal mine slope is excavated to final production line, the safety coefficient is 2.98, with the excavation, the deformation of the Fushun No.1 Refinery Factory area increases. (2) With the increase of backfilling, the slope coefficient increases to 3.32, this will reduce the deformation of the Fushun No.1 Refinery Factory area. Furthermore, the positions of the dangerous slip surface and serious deformation part of factory area should be regards as key areas. These conclusions could provide technical basis for the stability analysis of Fushun west open-pit coal mine.

scholarly journals Support design of main retracement passage in fully mechanised coal mining face based on numerical simulation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yalong Li ◽  
Mohanad Ahmed Almalki ◽  
Cheng Li
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Control Measures ◽  
Coal Face ◽  
Support Design ◽  
Working Face ◽  
Surrounding Rock Control ◽  
Mining Face ◽  
Mining Pressure

Abstract For the comprehensive mechanised coal mining technology, the support design of the main withdrawal passage in the working face is an important link to achieve high yield and efficiency. Due to the impact of mining, the roof movement of the withdrawal passage is obvious, the displacement of the coal body will increase significantly, and it is easy to cause roof caving and serious lamination problems, and even lead to collapse accidents, which will affect the normal production of the mine. In this paper, the mining pressure development law of the main withdrawal passage support under the influence of dynamic pressure is designed, the most favourable roof failure form of the withdrawal passage is determined, and the action mechanism and applicable conditions of different mining pressure control measures are studied. The pressure appearance and stress distribution in the final mining stage of fully mechanised coal face are studied by numerical simulation. The deformation and failure characteristics and control measures of roof overburden in the last mining stage of fully mechanised coal face are analysed theoretically. Due to the fact that periodic pressure should be avoided as far as possible after the full-mechanised mining face is connected with the retracement passage, some auxiliary measures such as mining height control and forced roof blasting are put forward on this basis. The relative parameters of the main supporting forms are calculated. The main retracement of a fully mechanised working face in a coal mine channel is put forward to spread the surrounding rock grouting reinforcement, reinforcing roof, and help support and improve the bolt anchoring force, the main design retracement retracement channels in the channel near the return air along the trough for supporting reinforcing surrounding rock control optimisation measures, such as through the numerical simulation analysis, the optimisation measures for coal mine fully mechanised working face of surrounding rock is feasible. Numerical simulation results also show that the surrounding rock control of fully mechanised working face of coal mine design improvements, its main retreat channel under the roof subsidence, cribbing shrank significantly lower, and closer, to better control the deformation of surrounding rock, achieved significant effect, to ensure the safety of coal mine main retracement channel of fully mechanised working face support.

Stress Distribution Characteristics in Rock Surrounding Heading Face and its Relationship with Temporary Supporting

2014 ◽  
Vol 568-570 ◽  
pp. 1684-1689
Author(s):  
Zhong Han Chen
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Zenith Distance ◽  
Rock Stability ◽  
Coal Roadway ◽  
Temporary Support ◽  
The Stability ◽  
Roadway Deformation ◽  
Mine Roof ◽  
Roof Deformation

To solve the problem of underground tunneling face from the empty top, using FLAC3D analysis software, surrounding rock stability for coal roadway 2-1121 of Ganhe Coal Mine are analyzed in numerical calculation. (1) During the tunneling, distance drivage face head-on 0.5-1m at the roof of roadway deformation and destruction features are more obvious, the two sides of roadway are even more significant. (2) Ganhe Coal Mine roof deformation has been established with different empty the experience formula of the zenith distance, obtained Ganhe underground tunneling face reasonable empty zenith distance is 3.5m. (3) Temporary support can obviously reduce roof deformation, reduce thickness of plastic zone of the top, to improve the stability of surrounding rock tunneling faces.

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