scholarly journals Study on Surrounding Rock-Bearing Structure and Associated Control Mechanism of Deep Soft Rock Roadway Under Dynamic Pressure

2019 ◽  
Vol 11 (7) ◽  
pp. 1892 ◽  
Author(s):  
Dongdong Qin ◽  
Xufeng Wang ◽  
Dongsheng Zhang ◽  
Xuyang Chen
Keyword(s):  
Dynamic Pressure ◽  
Soft Rock ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Control Effect ◽  
Pressure Relief ◽  
Reinforcement Scheme ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

Providing support for deep soft rock roadways under dynamic pressure is a major technical challenge. In this study, the distribution characteristics of surrounding rock-bearing structure of such roadways were systematically examined using theoretical analysis and numerical simulation. Based on the control effect of different support methods on the surrounding rock-bearing structure; a reinforcement scheme for deep dynamic soft rock roadway was proposed and applied. The results indicate that: (1) by increasing the supporting strength of the internal bearing structure, cohesion, and internal friction angle of the surrounding rock, and by reducing the influence of mining, making the external bearing structure close to the roadway and reducing the thickness of the bearing structure, can improve the bearing capacity of the shallow surrounding rock in the roadway; (2) under the conditions of dynamic load and creep of the surrounding rock; the deformation of the rock increases significantly; external bearing structure is far away from the roadway, and thickness of the bearing structure increases; anchor cable support and floor pressure relief effect better control over the roof and the roadside deformation and floor heave, respectively; and the thickness of the corresponding external bearing structure is reduced by 30.84% and 41.50%, respectively; and (3) based on the application, the zonal reinforcement scheme of “fix cable to shed, floor pressure relief, deep-shallow composite grouting” is proposed and put into practice, with good results. The results of this study can provide theoretical support and reference for the determination of supporting parameters in deep roadways.

Study on Surrounding Rock Deformation Characteristics and Control Technology in Deep Soft Rock Roadway

2012 ◽  
Vol 594-597 ◽  
pp. 631-635 ◽  
Author(s):  
Wen Hua Zha ◽  
Xin Zhu Hua
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Control Technology ◽  
Deformation Characteristics ◽  
Control Effect ◽  
Tunnel Support ◽  
Technical Problems ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Rock Roadway

To explore support technical problems in deep soft rock roadway, according to deep complicated geological conditions in 102 transport rise of Yuandian Mine, obtaining deformation characteristics of roadway in the initial support scheme under conditions, analysing the reasons of instability and failure of surrounding rock, proposing the surrounding rock control technology of step-by-step strengthen co-supporting, determining secondary anchor cable strengthen support time and grouting delay distance, optimizing the parameters of roadway support. Industrial practice show that the control effect of deformation was obvious,which provide the reference for deep soft rock tunnel support decision.

scholarly journals Instability Mechanism and Key Control Technology of Deep Soft Rock Roadway under Long-Term Water Immersion

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wei Jing ◽  
Xu Wang ◽  
Pengwei Hao ◽  
Laiwang Jing ◽  
Weipei Xue
Keyword(s):  
Water Immersion ◽  
Soft Rock ◽  
Surrounding Rock ◽  
The Self ◽  
Instability Mechanism ◽  
Roadway Support ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

More and more attention has been paid to the supporting problem of deep soft rock roadway floor with long-term water immersion in recent years. However, the existing soft rock roadway support technology rarely takes into account the influence of the immersion softening phenomenon of the roadway floor and the self-supporting structure characteristics of the surrounding rock on the stability of the surrounding rock at the same time, and the influence of the creep characteristics of rock on the deformation zone of the surrounding rock requires further research on the nature and division of the self-supporting structure of the surrounding rock. In response to the issues mentioned, based on the loading and unloading properties of the surrounding rock of the soft rock roadway, a new concept of the internal and external self-bearing structure was proposed. The fact of water-immersed mudstone softening in the soft rock roadway floor was revealed through the field practice, and the shape of the internal and external bearing structure was determined based on the in situ monitoring results. Then, the instability mechanism of the internal and external self-bearing structure of the surrounding rock was analyzed, the position of the critical control point was calculated, and the key control technology based on the method of controlling floor heave by using double-row anchor cables to control the deformation of the roadway sides was put forward. Finally, the field industrial test showed that this support technology can effectively control the deformation and failure of soft rock roadway in the case of water immersion on the floor. This work can provide a technical reference for similar roadway support designs.

Research of Bearing Mechanism of Double Support Structure of Deep Soft Rock Roadway

2013 ◽  
Vol 734-737 ◽  
pp. 606-613 ◽  
Author(s):  
Feng Jie Zhang ◽  
Pan Liu ◽  
Xiang Rui Meng ◽  
Zhao Ning Gao
Keyword(s):  
Soft Rock ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Support Structure ◽  
Double Support ◽  
Horizontal Strain ◽  
Definition Of ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

the stabilization of the rock support structure is the key to the safety and stability in the deep soft rock roadway, According to the bearing characteristics of surrounding rock, this paper puts forward the definition of double bearing structure, using FLAC3D numerical simulation software and theory of mechanics analyses Bearing Mechanism of Double Support Structure. The research shows: Excavation of soft rock roadway, the vertical strain and horizontal strain of the surrounding rock of roadway has wave, the surround rock appearing obvious deformation and displacement of roadway roof and floor in 3M, and the roadside appearing extrusion failure in the range of 2m. The roadway is more stable as the figure of the plastic radius is smaller, the same to outer bearing structure’s boundary and the width of outer bearing structure and plastic zone.

scholarly journals Modeling and Simulation of Deformation Mechanism of Soft Rock Roadway considering the Mine Water

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-22
Author(s):  
Yanlong Chen ◽  
Qiang Li ◽  
Hai Pu ◽  
Peng Wu ◽  
Liang Chen ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mine Water ◽  
Maximum Shear Stress ◽  
Soft Rock ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Support Principle ◽  
And Control ◽  
Soft Rock Roadway ◽  
Rock Roadway

The existence of coal mine water has an important influence on the instability of soft rock roadway in mining engineering. Considering the effect of mine water, a case study on the fracture mechanism and control technology of soft rock roadway was performed in this paper. The results showed that with the increase of moisture content, the uniaxial compressive strength of mudstone nonlinearly decreased, while the tensile strength, Young’s modulus, cohesion, and friction angle tended to a linear decrease approximately. Meanwhile, with the increase of the weakening coefficient, the axial force of the anchorage body increased gradually, while the maximum shear stress decreased gradually. With the increase of moisture content, the failure zone was further propagated into the deep surrounding rock, resulting in a larger stress relaxation around the roadway, especially in the roof and floor. Finally, the supporting technology of the roadway was proposed, and then its support principle, design process, and parameters were also analyzed in detail. The field monitoring data showed that the support technology can control the surrounding rock deformation effectively and maintain the long-term stability of the roadway.

scholarly journals Evolution of Interior and Exterior Bearing Structures of the Deep-Soft-Rock Roadway: From Theory to Field Test in the Pingdingshan Mining Area

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4357
Author(s):  
Qingxian Huang ◽  
Xufeng Wang ◽  
Xuyang Chen ◽  
Dongdong Qin ◽  
Zechao Chang
Keyword(s):  
Field Test ◽  
Soft Rock ◽  
Field Measurements ◽  
Mining Area ◽  
Surrounding Rock ◽  
Roadway Stability ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

Pingdingshan mining area is one of the typical deep mining areas in China, and most of the mines in this area are troubled by the difficulties of the deep-soft-rock roadway support. Based on the concept of synergistic interactions of the interior and exterior bearing structure of the surrounding rock and, considering the specific geological conditions of the research site, we establish the mechanical model of the interior and exterior bearing structure of the roadway. Based on numerical simulation, we reveal the influence of main factors, such as support strength and mechanical characteristics, of surrounding rock on the distribution and evolution of the interior and exterior bearing structure. We found that increasing the support strength and mechanical parameters of surrounding rock can make the exterior bearing structure close to the roadway enhance the bearing characteristics of the interior and exterior bearing structure and improve the roadway stability. The distribution characteristics of the interior and exterior bearing structure of the roadway under six different support strengths and six different grouting parameters were systematically investigated by field measurements. According to the field test results, an effective strategy for controlling the deep-soft-rock roadway is proposed, which provides a good reference for surrounding rock control of the deep-soft-rock roadway in the Pingdingshan mining area and mines with similar mining conditions.

scholarly journals Optimal Support Solution of Soft Rock Roadway Based on Drucker-Prager Yield Criteria

2021 ◽  
Author(s):  
Minghui Ma ◽  
Qifeng Guo ◽  
Jiliang Pan
Keyword(s):  
Internal Friction ◽  
Soft Rock ◽  
Friction Angle ◽  
Surrounding Rock ◽  
Term Strength ◽  
Maximum Displacement ◽  
Calculation Results ◽  
Soft Rock Roadway ◽  
Rock Roadway

Abstract Through theoretical calculation, the stress and deformation of surrounding rock can be analyzed, which can provide guidance for support design and optimization of soft rock roadway. In this paper, theoretical solutions for both the optimal support pressure and the allowable maximum displacement of surrounding rock are derived based on the Drucker-Prager (DP) yield criteria and the steady creep criterion expressed by the third invariant of deviator stress. The DP criteria with different parameters are compared and analyzed by an engineering example. Then, based on the calculation results, the effects of long-term strength, cohesion and internal friction angle of soft rock on the maximum plastic zone radius and allowable maximum displacement of roadway are discussed. The results show that the optimal support solution of soft rock roadway based on DP criteria can not only reflect the intermediate principal stress reasonably, but also can compare and discuss the influence of different DP criteria on the calculation results. The higher the long-term strength of the roadway surrounding rock is, the smaller the optimal support force is and the larger the allowable maximum displacement is. When the calculated long-term strength of soft rock can ensure that the deformation of the roadway does not exceed the allowable maximum displacement, the roadway can maintain long-term stability without support. With the increase of the cohesion or internal friction angle of soft rock, the radius of plastic zone decreases gradually, and the allowable maximum displacement is reduced by degrees. Through grouting and other means to improve the strength of surrounding rock can effectively reduce the roadway deformation and save support costs.

Strength Assessments of Concrete-Filled Steel Tubular Support of Soft Rock Roadway

2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Flexural Performance ◽  
Laboratory Test Results ◽  
Different Types ◽  
Soft Rock Roadway ◽  
Core Concrete ◽  
Rock Roadway

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.

Study on the Application of Bolt-Grout Reinforcement in the Deep Soft Rock Roadway

2011 ◽  
Vol 90-93 ◽  
pp. 1956-1959 ◽  
Author(s):  
Zhi Lin Dun ◽  
Da Shuai Ren ◽  
Lian Wei Ren
Keyword(s):  
Soft Rock ◽  
Field Monitoring ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Mining Depth ◽  
Air Inlet ◽  
Strata Behavior ◽  
Soft Rock Roadway ◽  
Two Sides ◽  
Rock Roadway

With the increasement of mining depth, the strata behavior of the roadway is obvious. As the stress of surrounding rock increases, the bottom of the soft rock roadway becomes deformed easily compressed by its top rock and two sides rock, which leads to the occurrence of the pucking and roadway destruction. Aiming the air inlet roadway destruction phenomenon of -450th level powder magazine in Hebi Zhongtai Mining Co.Ltd, the geological condition and the mechanism of the roadway failure are analysed comprehensively, and the bolt-grout supporting method is also proposed in this paper. At last, the deformation and heaving floor are controlled effectively which is proved by the field monitoring results.

An Experimental Study of Soft Rock Roadway with Anchored Support Structure Based on Nested Mechanical Analysis Model

2011 ◽  
Vol 90-93 ◽  
pp. 277-283
Author(s):  
Fu Sheng Liu ◽  
Gang Gang Dong ◽  
Su Hua Wang ◽  
Shao Jie Wang ◽  
Yang Song
Keyword(s):  
Design Method ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Soft Rock ◽  
Mechanical Analysis ◽  
Analysis Model ◽  
Support Structure ◽  
Three Dimensional Finite Element ◽  
Soft Rock Roadway ◽  
Rock Roadway

This paper chooses anchored support engineering of ore dynamic pressure soft rock roadway Qinan, Huaibei city as an example, and with the help of nested mechanical analysis model of anchored support structure, the paper analyzes the range of elastoplasticity, the range of anchor note area, stress and displacement of original rocks of the reinforced project, and simulates three-dimensional finite element numerical and underwent engineering detection of the project. Practicality and validity of quantitative control design method of anchored support structure are proved by comparing the theoretic research, calculation results, and field measurement results.

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