scholarly journals Analysis of the Stability and Mechanical Characteristics of the Jointed Surrounding Rock and Lining Structure of a Deeply Buried Hydraulic Tunnel

2022 ◽  
Vol 18 (1) ◽  
pp. 29-39
Author(s):  
Changchang Li ◽  
Zuguo Mo ◽  
Haibo Jiang ◽  
Fengchun Yang
Keyword(s):  
Mechanical Characteristics ◽  
Surrounding Rock ◽  
Lining Structure ◽  
The Stability

scholarly journals A Large Goaf Group Treatment by means of Mine Backfill Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hanwen Jia ◽  
Baoxu Yan ◽  
Erol Yilmaz
Keyword(s):  
Group Treatment ◽  
Laser Scanning ◽  
Large Scale ◽  
Mechanical Characteristics ◽  
Three Dimensional ◽  
Stability Diagram ◽  
Surrounding Rock ◽  
Mine Backfill ◽  
Treatment Scheme ◽  
The Stability

There are few studies on the management methods of large-scale goaf groups per the specific surrounding rock mass conditions of each goaf. This paper evaluates comprehensively the stability of the multistage large-scale goaf group in a Pb-Zn mine in Inner Mongolia, China, via the modified Mathews stability diagram technique. The volume of each goaf to be backfilled was quantitatively analyzed in the combination of theoretical analysis and three-dimensional laser scanning technology. The corresponding mechanical characteristics of the filling were determined by laboratory testing while formulating the treatment scheme of the large goaf group using the backfill method. The applicability of the treatment scheme using the backfill was verified by the combination of the numerical results of the distribution of the surrounding rock failure zone and the monitored data of the surface subsidence. The research results and treatment scheme using the backfill can provide a reference for similar conditions of mines worldwide.

scholarly journals Influence of Loose Contact between Tunnel Lining and Surrounding Rock on the Safety of the Tunnel Structure

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1733
Author(s):  
Zijian Ye ◽  
Chengping Zhang
Keyword(s):  
Contact Area ◽  
Three Dimensional ◽  
Field Investigation ◽  
Surrounding Rock ◽  
Tunnel Lining ◽  
Point Of View ◽  
Railway Tunnel ◽  
Contact State ◽  
Lining Structure ◽  
The Stability

The improvement of the contact state between the surrounding rock and tunnel lining, such as the effect of back-fill grouting behind lining, was important for maintaining the stability of the lining structure. To explore the influence of loose contact states behind lining on the safety of tunnel lining, a case of field investigation in a railway tunnel with a symmetrical lining structure was presented in this paper. A model test was conducted to prove the accuracy of the numerical simulation in the condition of dense contact state between the lining and surrounding rocks. Based on this, the three-dimensional (3-D) impact of loose contact states on the mechanic behavior of the lining structure under different compactness and different loose contact areas behind lining was investigated and summarized. Furthermore, the influence of the percentage of the insufficient strength behind lining was explored. Finally, the grade of the influence of the loose contact state on the safety of the lining structure was classified. The results revealed that: (1) in order to maintain the stability of lining structure, the compactness of the back-fill grouting behind lining was recommended to be above 80%, and the range of the loose contact area should be no more than 60 degree; (2) the strength of the back-fill grouting behind lining should be above 50% strength of the surrounding rock, the loose contact state behind lining should be improved in time to avoid expansion of the loose contact area; and (3) the classification of the influence grade on the safety of the lining structure provides a basic reference for controlling the quality of the back-fill grouting. This research gives a new point of view for the evaluation of the contact state between lining and surrounding rock.

Research on Support Technology in Deep Roadway of Huafeng Mine

2013 ◽  
Vol 753-755 ◽  
pp. 831-834
Author(s):  
Jie Kong ◽  
Peng Chen ◽  
Jun Chen ◽  
Qing Shu Liu ◽  
Zhen Ma
Keyword(s):  
Service Life ◽  
Mechanical Characteristics ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Strata Control ◽  
Reference Function ◽  
The Stability ◽  
Inclined Angle ◽  
Roadway Deformation ◽  
Physical And Mechanical Characteristics

Huafeng mine 1141 roadway (the 5th) that the buried depth is nearly 1000m, the angel of roadway is larger, the physical and mechanical characteristics of surrounding rock are poor, belongs to typical large inclined angle soft rock deep roadway. Using the reasonable supporting way is very important to control the deformation of the surrounding rock in roadways. The strata control observation shows that the roadway deformation is in a predictable range, could effectively ensure the stability and service life of 1141 roadway (the 5th) by using combined support of anchor, bolting with band and net, composite U shape shed. It can provide reference function to the supporting way of similar deep roadway.

scholarly journals Research and Analysis on the Supporting Structure of the Second Lining of the Tunnel in the Phyllite Stratum

2020 ◽  
Vol 198 ◽  
pp. 02014
Author(s):  
Wei Zhiquan ◽  
Huang Baisheng ◽  
Yang Lu ◽  
Wei Yonghao ◽  
Qiu Jianqiao
Keyword(s):  
Plastic Zone ◽  
Surrounding Rock ◽  
Supporting Structure ◽  
Geological Conditions ◽  
Lining Structure ◽  
Calculation Results ◽  
Main Period ◽  
Secondary Lining ◽  
The Stability ◽  
The Impact

The reasonable construction of the secondary lining structure of the tunnel is an important link to ensure the stability of the surrounding rock of the tunnel. Taking a phyllite stratum tunnel project in Jiangxi as the background, the Flac3D finite difference software was used to numerically simulate and analyze the supporting structure of the secondary lining. The impact of support timing on surrounding rock stress. The calculation results show that with the progress of the construction step, the main period of the displacement of the vault is after the excavation of the upper section of the tunnel before the upper section support; The plastic zone of the surrounding rock changes obviously, especially above the tunnel, and finally the plastic zone develops to the ground; the stress of the surrounding rock shows a decreasing trend with the increase of the time of the secondary lining. The research results can provide certain guiding significance for the construction of the second lining of the tunnel under similar geological conditions.

scholarly journals Effect of the Location of Fault Fracture Zones on the Stability of Symmetrical Submarine Tunnels

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1111
Author(s):  
Wei Fang ◽  
Gang Wang ◽  
Chang Wang
Keyword(s):  
Safety Factor ◽  
Working Conditions ◽  
Axial Force ◽  
Fracture Zone ◽  
Bending Moment ◽  
Surrounding Rock ◽  
Fracture Zones ◽  
Fault Fracture Zone ◽  
Lining Structure ◽  
The Stability

In this paper, we aim to reveal the influence of fault fracture zones on the stability of submarine tunnels and the surrounding rock under different water and drainage measures. Firstly, four typical working conditions of submarine tunnels intersecting with fault fracture zones were selected. On the basis of the typical cross section of the intersections of submarine tunnels and faults, they were divided into four working conditions. Then, the displacement and plastic zones of the surrounding rock of the tunnel were studied, and the stability of the rock surrounding the submarine tunnel was discussed. This research structure indicates that the bending moment and axial force of the lining structure of the submarine tunnel increase with increasing sealing degree, but the safety factor exhibits a downward trend. When the fault fracture zone goes through the section above the tunnel axis, the bending moment and axial force at the lining vault are greater than the other working conditions, and the displacement of the surrounding rock at the vault and spandrel is prominent. When the fault fracture zone completely passes through the tunnel, the safety factor of the lining structure is at its lowest, and the displacement of the surrounding rock at the arch waist develops laterally. When the fault fracture zone passes through the part below the tunnel axis, the arch foot displacement converges significantly, and the surrounding rock displacement exhibits a downward inclination. In addition, the plastic zone is mainly developed in the arch and the shoulder. These research results provide a reliable reference for tunnel design and excavation support.

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.

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.

Hydro-Mechanical Coupled Analysis of the Stability of Surrounding Rock Mass of Underground Water-Sealed Oil Storage

2013 ◽  
Vol 405-408 ◽  
pp. 402-405 ◽  
Author(s):  
Yun Jie Zhang ◽  
Tao Xu ◽  
Qiang Xu ◽  
Lin Bu
Keyword(s):  
Rock Mass ◽  
Underground Water ◽  
Surrounding Rock ◽  
Comsol Multiphysics ◽  
Coupled Analysis ◽  
Coupling Theory ◽  
Oil Storage ◽  
Stability Of Surrounding Rock ◽  
Straight Wall ◽  
The Stability

Based on the fluid-solid coupling theory, we study the stability of surrounding rock mass around underground oil storage in Huangdao, Shandong province, analyze the stress of the surrounding rock mass around three chambers and the displacement change of several key monitoring points after excavation and evaluate the stability of surrounding rock mass using COMSOL Multiphysics software. Research results show that the stress at both sides of the straight wall of cavern increases, especially obvious stress concentration forms at the corners of the cavern, and the surrounding rock mass moves towards the cavern after excavation. The stress and displacement of the surrounding rock mass will increase accordingly after setting the water curtains, but the change does not have a substantive impact on the stability of surrounding rock mass.

scholarly journals Simulation of the Load Evolution of an Anchoring System under a Blasting Impulse Load Using FLAC3D

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xigui Zheng ◽  
Jinbo Hua ◽  
Nong Zhang ◽  
Xiaowei Feng ◽  
Lei Zhang
Keyword(s):  
Shear Stress ◽  
Dynamic Response ◽  
Axial Force ◽  
Mechanical Characteristics ◽  
Oscillation Amplitude ◽  
Anchoring System ◽  
Impulse Load ◽  
The Stability ◽  
Calculation Software ◽  
Dynamic Perturbation

A limitation in research on bolt anchoring is the unknown relationship between dynamic perturbation and mechanical characteristics. This paper divides dynamic impulse loads into engineering loads and blasting loads and then employs numerical calculation software FLAC3Dto analyze the stability of an anchoring system perturbed by an impulse load. The evolution of the dynamic response of the axial force/shear stress in the anchoring system is thus obtained. It is revealed that the corners and middle of the anchoring system are strongly affected by the dynamic load, and the dynamic response of shear stress is distinctly stronger than that of the axial force in the anchoring system. Additionally, the perturbation of the impulse load reduces stress in the anchored rock mass and induces repeated tension and loosening of the rods in the anchoring system, thus reducing the stability of the anchoring system. The oscillation amplitude of the axial force in the anchored segment is mitigated far more than that in the free segment, demonstrating that extended/full-length anchoring is extremely stable and surpasses simple anchors with free ends.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

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