scholarly journals A Study of the Large Deformation Mechanism and Control Techniques for Deep Soft Rock Roadways

2018 ◽  
Vol 10 (4) ◽  
pp. 1100 ◽  
Author(s):  
Xiaojie Yang ◽  
Eryu Wang ◽  
Yajun Wang ◽  
Yubing Gao ◽  
Pu Wang
Keyword(s):  
Large Deformation ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Control Techniques ◽  
And Control

Support principles of NPR bolt/cable and control techniques of large-deformation disasters

2016 ◽  
Vol 26 (6) ◽  
pp. 967-973 ◽  
Author(s):  
Zhigang Tao ◽  
Haijiang Zhang ◽  
Yifan Chen ◽  
Chaochao Jiang
Keyword(s):  
Large Deformation ◽  
Control Techniques ◽  
And Control

Analysis of Deformation Mechanism and Control Technology of Soft Rock Tunnel with High Geostress

2014 ◽  
Vol 638-640 ◽  
pp. 794-797
Author(s):  
Fei Pan ◽  
Sheng Guo Cheng
Keyword(s):  
Deformation Mechanism ◽  
Traffic Engineering ◽  
Soft Rock ◽  
Control Technology ◽  
Engineering Construction ◽  
Deformation Control ◽  
High Geostress ◽  
Rock Tunnels ◽  
Rock Tunnel ◽  
And Control

With the development of transportation construction, soft rock tunnel with high geostress construction has become a key problem to overcome of traffic engineering construction. In order to explore the deformation mechanism and control technology of soft rock tunnel with high geostress, Xiakou tunnel engineering as an example, the geological characteristics and deformation characteristics of the tunnel were analyzed, to obtain the deformation mechanism of soft rock tunnels with high geostress, and to develop deformation control technology, the results provide a basis and reference for the domestic and foreign the similar engineering construction.

scholarly journals Tunnel Collapse Mechanism and Its Control Strategy in Fault Fracture Zone

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jin Zhang ◽  
Mengxue Wang ◽  
Chuanhao Xi
Keyword(s):  
Large Deformation ◽  
Deformation Mechanism ◽  
Fracture Zone ◽  
Theoretical Research ◽  
Collapse Mechanism ◽  
Control Effect ◽  
Geological Conditions ◽  
Fault Fracture Zone ◽  
Reinforcement Measures ◽  
And Control

Complex geological conditions such as fault fracture zone will have a significant adverse impact on tunnel engineering, and collapse, large deformation, and other problems are prominent. The research on the large deformation mechanism and control of tunnel crossing fault fracture zone can provide guidance for tunnel safety construction. Based on the Jingzhai tunnel, combined with geological analysis, theoretical research, numerical simulation, and other means, this paper studies and analyzes the large deformation mechanism of the tunnel. The control effect of different advanced reinforcement measures is studied.

scholarly journals A Case Study on Optimization and Control Techniques for Entry Stability in Non-Pillar Longwall Mining

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 391 ◽  
Author(s):  
Xiaojie Yang ◽  
Eryu Wang ◽  
Xingen Ma ◽  
Guofeng Zhang ◽  
Ruifeng Huang ◽  
...  
Keyword(s):  
Large Deformation ◽  
Longwall Mining ◽  
Surrounding Rock ◽  
Control Techniques ◽  
Immediate Roof ◽  
Optimization And Control ◽  
Pillar Mining ◽  
And Control ◽  
Entry Roof

In order to reduce large deformation failure occurrences in non-pillar longwall mining entries due to roof weighting behaviors, a case study in Halagou coal mine was conducted on optimization and control techniques for entry stability in non-pillar longwall mining. The Universal Discrete Element Code (UDEC) modeling was adopted to study entry stability in non-pillar mining, and the characteristics of deformation and stress and crack propagation were revealed. The large deformation transmission between the entry-immediate roof and the gob-immediate roof could be eliminated by optimizing the entry roof structure through a directional roof-cutting method. The localized tensile stresses generated in the entry-surrounding rock caused the generation of coalescent macroscopic fractures, which resulted in the instability of the entry. The tensile stress state could be inhibited by an active flexible support system through enhancing the confining pressure on the surrounding rock. Serious rotation subsidence occurs in the entry roof due to periodic weighting of the main roof, which could be greatly reduced by a passive rigid support pattern. The numerical and field test results both showed that the roof weighting pressure was offloaded by the technique and that the deformation of the entry surrounding the rock in non-pillar mining was quite small. Thus, the technique can effectively ensure the stability of the gob-side entry, which can provide references for entry stability control in non-pillar longwall mining.

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

2019 ◽  
Vol 11 (22) ◽  
pp. 6243 ◽  
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.

scholarly journals Study on Deformation Mechanism and Support Measures of Soft Surrounding Rock in Muzhailing Deep Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Zhigang Tao ◽  
Jindong Cao ◽  
Liu Yang ◽  
Aipeng Guo ◽  
Ruifeng Huang ◽  
...  
Keyword(s):  
Large Deformation ◽  
Support System ◽  
Deformation Mechanism ◽  
High Stress ◽  
Soft Rock ◽  
Maximum Principal Stress ◽  
Surrounding Rock ◽  
Single Type ◽  
Deep Tunnel ◽  
Support Measures

The deformation of Muzhailing deep tunnel is about 2.3 m in the process of construction, which is difficult to be controlled by the traditional “anchor-grouting integration” support system. This paper deeply analyzes the geological characteristics, rock mechanics characteristics, and surrounding rock failure characteristics of Muzhailing tunnel. The deformation mechanism and the failure of the support system are analyzed through the numerical simulation, theoretical analysis, and field test. The authors propose support measures suitable for Muzhailing tunnel based on the analysis results. The maximum buried depth is 600 m, and the engineering rock mass at the depth has nonlinear physical and mechanical phenomenon. The maximum principal stress of Muzhailing tunnel is 25.7 MPa, which belongs to high-stress joint swelling soft rock tunnel. The NPR cable can achieve large deformation under the condition of constant support resistance. The authors put forward the coupling support mode of “NPR cable + steel arch frame + concrete,” which is based on the idea of transforming the composite deformation mechanism to a single type. The stress concentration appears in the range of 12 m in the surrounding rock circle, and the lateral and vertical stress distributions are relatively symmetrical after the improved support. The circumferential strain of the surrounding rock is greatly reduced, and the range of strain is reduced by 10%. The field monitoring results show that the new support system can well control the large soft rock deformation of Muzhailing tunnel (0.5 m). The support strategy proposed can effectively control the large deformation and promote the formation of new support concept for deep tunnel.

PROJECT ON ELECTRONIC STEERING SYSYTEM

2018 ◽  
Vol 4 (5) ◽  
pp. 7
Author(s):  
Shivam Dwivedi ◽  
Prof. Vikas Gupta
Keyword(s):  
Steering System ◽  
Essential Elements ◽  
Variable Pressure ◽  
Passenger Cars ◽  
Control Techniques ◽  
Steering Mechanism ◽  
Dynamics And Control ◽  
Active Research ◽  
Electronic Steering ◽  
And Control

As the four-wheel steering (4WS) system has great potentials, many researchers' attention was attracted to this technique and active research was made. As a result, passenger cars equipped with 4WS systems were put on the market a few years ago. This report tries to identify the essential elements of the 4WS technology in terms of vehicle dynamics and control techniques. Based on the findings of this investigation, the report gives a mechanism of electronically controlling the steering system depending on the variable pressure applied on it. This enhances the controlling and smoothens the operation of steering mechanism.

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