scholarly journals Experimental Study on Properties of Steel-plastic Geogrids and their Application in Supporting Engineering

2016 ◽  
Vol 10 (1) ◽  
pp. 525-537
Author(s):  
Qingbiao Wang ◽  
Rongshan Lü ◽  
Yingchun Kong ◽  
Lingyu Tang ◽  
Fei Xie ◽  
...  
Keyword(s):  
Creep Property ◽  
High Strength ◽  
Surrounding Rock ◽  
Good Resistance ◽  
Time Curve ◽  
Resistance To Deformation ◽  
Supporting Effect ◽  
The Stability ◽  
Prestressed Anchor ◽  
Surrounding Rock Deformation

Steel-plastic geogrid greatly improves the stability of surrounding rock in the supporting project due to the qualities, such as high strength, high toughness and less creep deformation. Through the geogrid mechanical properties analysis, tensile strength, deformation and creep test and field experiment and so on, we researched and analyzed steel-plastic geogrids’ characteristics and supporting effect, and concluded the influencing factors of steel-plastic geogrids’ characteristics, load-time curve and the steel-plastic geogrids’ variation under different temperature. We explained steel-plastic geogrids’ supporting effect through specific examples of projects. The results of the studies are listed as follows: (1) Steel-plastic geogrid has good resistance to deformation and node failure of roadway surrounding rock deformation, which has good tensile property, creep property and deflection performance; (2) It is feasible to support the surrounding rock by forming a whole combined joint support with steel- plastic geogrid and high-strength prestressed anchor rod.

Research on Supporting Technology of Roadway Driving along Next Goaf of Second Mining Strip Pillar

2012 ◽  
Vol 446-449 ◽  
pp. 1657-1660
Author(s):  
Wei Dong Lv ◽  
Nan Nan Zhao
Keyword(s):  
Abutment Pressure ◽  
High Strength ◽  
Main Roof ◽  
Surrounding Rock ◽  
Control Effect ◽  
General Stability ◽  
High Strength Bolt ◽  
Mining Face ◽  
The Stability ◽  
Surrounding Rock Deformation

For roadway driving along next goaf of strip pillar second mining, being influenced by the abutment pressure of previous coal mining face and main roof breaking rotary deformation, the surrounding rock deformation is serious and the control effect of ordinary bolt supporting on the general stability of roadway driving along next goaf is poorer. According to the concrete geological and technique condition of the 2351 second mining strip pillar in Daizhuang Colliery, adopting the united support pattern combined high strength bolt of levorotatory continuous thread and anchor of low relaxation prestress, the safety of the roadway can be ensured and the stability of the roadway surrounding rocks can be improved. It is of significant reference meaning for bolting support of roadway driving along next goaf of second mining strip pillar under similar condition.

Coal Seam Roadway Bolt Support Design Method Based on the Supporting Theory of Broken Rock Zone

2013 ◽  
Vol 734-737 ◽  
pp. 535-539
Author(s):  
Hai Yuan Liu ◽  
Zhi Gang Wang ◽  
Ji Li ◽  
Lang Bai
Keyword(s):  
Theoretical Foundation ◽  
Design Method ◽  
Field Application ◽  
Surrounding Rock ◽  
Support Design ◽  
Roadway Support ◽  
The Stability ◽  
Comprehensive Classification ◽  
Classification Index ◽  
Surrounding Rock Deformation

broken rock zone is the main reason for the convergence of surrounding rock deformation, and its thickness not only is a reflection of many factors which influence the stability of surrounding rock, but also is the results of the interaction of many factors, a comprehensive classification index. Roadway support design based on classification result of broken rock zone, has a solid theoretical foundation, and the field application effect is remarkable.

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.

scholarly journals Constant-Resistance, Rigid, and Flexible Coupling Support Technology for Soft Rock Entrances in Deep Coal Mines:A Case Study in China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yong Zhang ◽  
Chengwei Zhao ◽  
Ming Jiang ◽  
Jiaxuan Zhang ◽  
Chen Chen ◽  
...  
Keyword(s):  
Large Deformation ◽  
Support System ◽  
Soft Rock ◽  
High Strength ◽  
Surrounding Rock ◽  
Constant Resistance ◽  
The Stability ◽  
Control Principle ◽  
Soft Rock Roadway ◽  
Rock Roadway

The stability control of a soft rock roadway is a crucial problem for sustainable utilization of limited coal resources in deep mining practices. To solve it, the soft rock types and failure mechanism of −890 entrance surrounding rock have been analyzed, taking Daqiang Coal Mine of China as an engineering example. The analysis shows that the damage to the surrounding rock was characterized by asymmetry, large deformation, severe damage, and extended durations. The surrounding rock can be divided into high-stress-jointed-strong expansion soft rock based on S-M scanning and mineral analysis. Numerical simulation is used to reproduce the failure process of the original supporting system and analyze the deformation of the surrounding rock, range of plastic zone, and distribution of the stress field. The failure mechanism is thus defined for a deep soft rock roadway. Combined with the above studies, the deformation mechanics of the surrounding rock is summarized as type IABIIABIIIABC. The stability transformation mechanism of the surrounding rock is proposed, based on which the control principle of deformation stability of a surrounding rock is formed. According to the control principle, “high strength support controls the surrounding rock deformation. The large deformation of the flexible support system releases the accumulated energy to the surrounding rock, and long-term deformation of the surrounding rock is controlled by high strength truss support.” Meanwhile, the constant-resistance, rigid, and flexible coupling (CRRFC) support system is proposed. The numerical analysis demonstrated that the CRRFC support system can effectively reinforce the shallow surrounding rock and improve the bearing capacity. Simultaneously, the development of the surrounding rock malignant plastic zone is effectively controlled. The application results show that the large deformation of the roadway can be effectively controlled by the CRRFC support system, which provides applications for similar engineering.

Surrounding Rock Deformation Properties and Control Technique for Roadway along Goaf in Soft Rock

2014 ◽  
Vol 1010-1012 ◽  
pp. 1482-1486 ◽  
Author(s):  
Ming Yang ◽  
Xin Zhu Hua ◽  
Deng Hong Chen
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technique ◽  
Deformation Properties ◽  
Economical Benefit ◽  
Practical Engineering ◽  
Supporting Effect ◽  
And Control ◽  
Surrounding Rock Deformation

Deformation of roadway driving along goaf was very serious during mining in Qidong coal Mine.This paper took the roadway as the engineering background, firstly, numerical simulation of the roadway has been made by FLAC3D,then its surrounding rock deformation properties and stress distribution were analyzed,the reinforcement technology was proposed during mining, lastly, the deformation around roadway during mining was observed and analyzed. The practical engineering shows that : the combined supporting of bolting-shotcreting-grouting can effectively control the deformation around roadway, the supporting effect is good , and better social and economical benefit have been gotten.

The Surrounding Rock of Deep Borehole Pressure Relief and Let the Pressure Bolt Coupling Analysis

2013 ◽  
Vol 446-447 ◽  
pp. 1421-1424 ◽  
Author(s):  
Shu Guang Zhang ◽  
Long Chen ◽  
Hong Yu Jia
Keyword(s):  
Numerical Simulation ◽  
High Stress ◽  
High Strength ◽  
Surrounding Rock ◽  
Deformation Characteristics ◽  
Deep Borehole ◽  
Pressure Relief ◽  
High Strength Bolt ◽  
Supporting Effect ◽  
Coupling Support

Roadway borehole pressure relief and let the pressure anchor combined support technology were based on using the new pressure high strength bolt instead of ordinary bolt ,Combined with the borehole pressure relief principle, aim at releasing high stress of surrounding rock of roadway ,Complying with the deformation characteristics of supporting technology of the surrounding rock. In this paper, we used scaled numerical simulation technology —— ADINA to analyze the roadway borehole pressure relief and let the pressure anchor coupling support technology. To the tunnel, we used the method of numerical simulation of let the pressure bolt support independently, drilling pressure relief, and borehole pressure relief and let the pressure anchor coupling support three kinds of the comparison numerical simulation. The advantages of coupling supporting effect was elaborated, It was instructive for the deeply roadway engineering in the future.

Numerical Simulation Analysis of the Nanyangpo Coal Mine Anchor Support Method

2012 ◽  
Vol 619 ◽  
pp. 231-238
Author(s):  
Mei Chang Zhang ◽  
Peng Cheng Fei ◽  
De Long Zou
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Nursing Program ◽  
Load Carrying ◽  
Deformation Law ◽  
The Stability ◽  
Surrounding Rock Deformation ◽  
Bolt Support

The bolt support is important to ensure the stability of surrounding rock. Of Nan Yangpo mines as the research background. The application of numerical simulation software FLAC3D mine deep Bolt bolt support after the surrounding rock deformation law of the numerical simulation, Comparison and analysis of rock displacement and plastic zone under the support program changes. The results show that, The third bolt support nursing program, Significantly improve the strength and load carrying capacity of the surrounding rock, Effectively control the damage of the deep tunnel deformation that can control the roof of 4101 the return airway and two to help the stability.

scholarly journals Investigation of Deep Shaft-Surrounding Rock Support Technology Based on a Post-Peak Strain-Softening Model of Rock Mass

2021 ◽  
Vol 12 (1) ◽  
pp. 253
Author(s):  
Jianjun Zhang ◽  
Yang Wang ◽  
Baicong Yao ◽  
Dongxu Chen ◽  
Chuang Sun ◽  
...  
Keyword(s):  
Rock Mass ◽  
Strain Softening ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Surrounding Rock ◽  
Peak Strain ◽  
Rock Support ◽  
Support Structure ◽  
The Stability ◽  
Surrounding Rock Deformation

To control the large deformation that occurs in deep shaft-surrounding rock, the post-peak strain-softening characteristics of deep jointed rock mass are discussed in detail. An equivalent post-peak strain-softening model of jointed rock mass is established based on continuum theory and the geological strength index surrounding rock grading system, and numerical simulations are performed using FLAC3D software. The convergence-constraint method is used to analyze the rock support structure interaction mechanism. A composiste support technique is proposed in combination with actual field breakage conditions. During the initial support stage, high-strength anchors are used to release the rock stress, and high-stiffness secondary support is provided by well rings and poured concrete. This support technology is applied in the accessory well of a coal mine in Niaoshan, Heilongjiang, China. The stability of the surrounding rock support structure is calculated and analyzed by comparing the ideal elastic-plastic model and equivalent jointed rock mass strain-softening model. The results show that a support structure designed based on the ideal elastic-plastic model cannot meet the stability requirements of the surrounding rock and that radial deformation of the surrounding rock reaches 300 mm. The support structure designed based on the equivalent joint strain-softening model has a convergence rate of surrounding rock deformation of less than 1 mm/d after 35 days of application. The surrounding rock deformation is finally controlled at 140 mm, indicating successful application of the support technology.

scholarly journals Influence of Discontinuities on Rock Failure under Blasting at Shuangjiangkou Hydropower Station

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xi Zhao ◽  
Bangbiao Wu ◽  
Liyuan Yu ◽  
Tieshuan Zhao ◽  
Zhonghua Hu
Keyword(s):  
Impact Resistance ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Dynamic Tests ◽  
Support Design ◽  
Failure Characteristics ◽  
Underground Caverns ◽  
Geological Conditions ◽  
The Stability ◽  
Surrounding Rock Deformation

The underground caverns of Shuangjiangkou hydropower station are under complex geological conditions. During excavation, the stability of the tunnels is severely affected by problems, such as blasting impact and excavation unloading, resulting in abnormal deformation at different locations. On the basis of on-site measurement, the characteristics of rocks at the main powerhouse and the main transformer room are compared through dynamic tests, and a numerical model is established using discrete element method (DEM) to analyze the special influence of fault SPD9-f1 on the deformation after excavation. It is revealed that the surrounding rock of the main powerhouse has stronger impact resistance than that of the main transformer room and that the existence of fault SPD9-f1 accounts for the abnormal deformation. In this study, the failure characteristics and mechanism of surrounding rock deformation controlled by stress and fault are revealed, providing important references for the subsequent excavation and support design of underground projects.

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.

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