scholarly journals Study on the Reinforcement Measures and Control Effect of the Surrounding Rock Stability Based on the Shield Tunneling Under Overpass Structure

2016 ◽  
Vol 9 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Qian - cheng Fang ◽  
◽  
Li Shang ◽  
Yong - hui Shang ◽  
Ying Zhao ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Control Effect ◽  
Shield Tunneling ◽  
Rock Stability ◽  
Reinforcement Measures ◽  
And Control

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 A study on the geometric effects of a concrete filling body in remaining roadways with fully mechanised caving

2021 ◽  
Vol 18 (5) ◽  
pp. 681-690
Author(s):  
Minglei Zhang ◽  
Yue Yang ◽  
Linsheng Gao
Keyword(s):  
Bearing Capacity ◽  
Surrounding Rock ◽  
Control Effect ◽  
Reinforcement Scheme ◽  
Geometric Effect ◽  
Deformation Control ◽  
Rock Stability ◽  
Coal Deformation ◽  
Concrete Filling ◽  
Geometric Effects

Abstract To address the problem of the concrete filling body (CFB) force failing to reach test strength in remaining roadways, the weakening effects due to aspect ratio and dimensional parameters on the actual CFB strength were investigated in this study. The geometric effects of CFB (including hoop and size effects) as well as the geometric effect coefficient determination method were analysed. Through laboratory tests and PFC numerical simulations, the hoop and size effect coefficients of the CFB in the Gaohe Coal Mine were studied. Furthermore, the calculation equations of actual strength and bearing capacity of the CFB were derived. Regarding the filling body failure and coal deformation in the remaining roadway located at the No. W1319 working face, the actual bearing capacity of CFB and surrounding rock stability during secondary exploitation were theoretically studied. The investigation suggests the adoption of a grouting reinforcement scheme for surrounding rock. The field applications performed have demonstrated that the deformation control effect in the remaining-roadway surrounding rock was effectively improved during second mining and the filling body beside the roadway suffered no additional damage. Studying the geometric effect of CFB can provide some theoretical guidance and industrial significance to accurately identify the filling body strength and reduce the failure risk of surrounding rock in remaining roadways.

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 STUDY ON INTENSIVE DESIGN AND CONTROL OF CHAMBER GROUP UNDER THE CONDITION OF WEAK SURROUNDING ROCK

Mining Scince ◽  
2019 ◽  
Vol 26 ◽  
Author(s):  
Jun Yang ◽  
Shilin Hou ◽  
Kaifang Zhou ◽  
Bowen Qiao ◽  
Hongyu Wang ◽  
...  
Keyword(s):  
Stability Control ◽  
Field Application ◽  
Surrounding Rock ◽  
Control Measures ◽  
Wire Mesh ◽  
Rock Deformation ◽  
Control Effect ◽  
Obvious Effect ◽  
And Control ◽  
Surrounding Rock Deformation

In order to study the design and stability control of deep soft rock chamber group, taking ninth coal mine of Hebi Coal Power Co., Ltd. as the engineering background, The main problem in normal design is analyzed with the combined method of FLAC3D numerical simulation and field engineering test. and then puts forward targeted control measures and carries out field application. The results show that, compared with the conventional design, the intensive design can reduce the stress concentration degree and plastic zone range of the surrounding rock, as well as reduce the quantities. Compared with conventional supporting schemes, the surrounding rock deformation greatly reduces by more than 82% after adopting bolting and shotcreting with wire mesh + anchor cable + floor anchor supporting. Among them, the floor heave control has obvious effect, and the decreasing amplitude reaches more than 93%. The field application shows that the surrounding rock deformation of the main chamber is within the allowable range, and the chamber control effect is good. Therefore, the research results can provide reference for the design and control of similar chamber groups.

The Comparative Study on the Impact of Tunnel Excavation with Footage Different CRD to Testability of Surrounding Rock

2011 ◽  
Vol 243-249 ◽  
pp. 3417-3422
Author(s):  
Lin Po Shi ◽  
Bin Song Jiang ◽  
Yao Qiang Zhao
Keyword(s):  
Plastic Zone ◽  
Formation Control ◽  
Plastic Zone Size ◽  
Surrounding Rock ◽  
Zone Size ◽  
Control Effect ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
The Comparative Study ◽  
The Impact

This article used Geotechnical Engineering General Software FLAC3D to simulate the tunnel CRD method under 1.5m, 2.0m, 2.5 m, 3.0 m footage separately and analysis the influence to the tunnel surrounding rock stability in the different footage construction. This paper selected a real tunnel project as the research object and analysis comparatively the rule and characteristic of various methods of tunnel surrounding rock displacement, stress distribution and the plastic zone size through simulated computing the different footage construction. The results show that,Ⅰ.Considered from the surrounding rock stress control that the 1.5m footage adjacent formation stress adjustment effect is best, next is 2.0m, 2.5 m, 3.0 m;Ⅱ.Considered from the plastic zone size that the 1.5m footage control effect is best, next is in turn 2.0m, 2.5 m, 3.0 m;ⅢConsidered from the surrounding rock displacement control that 1.5 meter footage adjacent formation control effect is best, but 2.0 meter, 2.5 meters and 3.0 meter phase differences are not big.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

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