Study on the Deformation and Stability of Surrounding Rock

2012 ◽  
Vol 170-173 ◽  
pp. 465-469
Author(s):  
Sheng Ji Jin ◽  
Yong Qin Rui ◽  
Zhe Shu
Keyword(s):  
Nuclear Power ◽  
Surrounding Rock ◽  
Water Tunnel ◽  
Plastic Deformation Zone ◽  
Simulation Methods ◽  
Surrounding Area ◽  
Tunnel Excavation ◽  
Working Face ◽  
Stability Of Surrounding Rock ◽  
Numerical Simulation Methods

To rely on nuclear power plant water tunnel project, through the numerical simulation methods, we analysized the extent of rock deformation and stability of the process of excavation and supporting to reveal the deformation near the working face of rock tunnel.The research results show: When carrying out tunnel excavation, the plastic deformation zone in the horizontal direction perpendicular to the tunnel axis and the vertical downward direction are extended, the vault appears to sink, but also occurred in surface subsidence. Contrast the extent of tunnel excavation: The minimum extent is the tunnel axis perpendicular to the vertical downward, followed along the tunnel axis, the maximum extent is perpendicular to the direction of horizontal tunnel axis. Three kinds of excavation methods, a substantial volume reduction of sinking takes place in short steps and extra short steps excavation than the excavation of the top arch , and the surrounding area within the plastic is significantly reduced, which shows the smaller footage of the excavation the better control of the sinking of the crown.

Numerical Simulation for the Excavation in Tunnel Construction

2011 ◽  
Vol 90-93 ◽  
pp. 90-93
Author(s):  
Yong Suo Li ◽  
Ke Neng Zhang ◽  
Xian Yang ◽  
Chang Bo Huang
Keyword(s):  
Numerical Simulation ◽  
Tunnel Construction ◽  
Simulation Methods ◽  
Underground Engineering ◽  
Tunnel Excavation ◽  
Construction Procedure ◽  
Mine Excavation ◽  
Numerical Simulation Methods ◽  
Explicit Finite Difference ◽  
Real Practice

Tunnel excavation is often done in underground engineering such as civil tunnel construction and mine excavation. The numerical simulation can output colorful results to interpret the tunnel excavation effect more easier. Among all the numerical simulation methods, fast lagrangian explicit finite difference code of continua (FLAC3D) is widely used to solve practical problems, especially in field of elasto-plastic characteristic and construction procedure. So in the present paper, 3 steps of excavations in a tunnel is modeled by FLAC3D to present the stress and displacement distribution, and give guidance for the real practice.

scholarly journals Rockburst Identification Method Based on Energy Storage Limit of Surrounding Rock

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 343 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Chun Luo ◽  
Heng Zhang ◽  
Ruikai Gong
Keyword(s):  
Rock Mass ◽  
Energy Storage ◽  
Minimum Energy ◽  
Surrounding Rock ◽  
Underground Engineering ◽  
Tunnel Excavation ◽  
Working Face ◽  
Excavation Process ◽  
Storage Limit ◽  
The Impact

Rockbursts are one of the prominent problems faced by deep underground engineering. Not only do they affect the construction progress, but they also threaten the safety of construction personnel and equipment, and may even induce earthquakes. Therefore, the prediction of rockbursts has very important engineering significance for the excavation of deeply buried tunnels. In this paper, a new indicator for stability and optimization evaluation of hard, brittle surrounding rock under high geo-stresses, namely the minimum energy storage limit of surrounding rock induced by transient unloading, is proposed. In addition, the time for erecting support for tunnel excavation in the rockburst area and the impact of excavation dimensions on rockburst are investigated. The results show that transient unloading during the tunnel excavation process will reduce the energy storage limit of the rock mass. When the strain energy density of the local surrounding rock exceeds the minimum energy storage limit of the rock mass, the rock mass energy is suddenly released, and rockburst occurs. Rockburst is most likely to occur at 0.42–0.65 D away from the working face. The increasing length of a round adopted in high geo-stress areas will make the surrounding rock unstable and increase the probability of rockburst.

scholarly journals Comprehensive technical support for safe mining in ultra-close coal seams: A case study

2021 ◽  
pp. 014459872110093
Author(s):  
Wei Zhang ◽  
Jiawei Guo ◽  
Kaidi Xie ◽  
Jinming Wang ◽  
Liang Chen ◽  
...  
Keyword(s):  
Coal Seam ◽  
Technical Support ◽  
Surrounding Rock ◽  
Coal Seams ◽  
Deformation Control ◽  
Hard Roof ◽  
Working Face ◽  
Close Coal Seams ◽  
Safe Mining

In order to mine the coal seam under super-thick hard roof, improve the utilization rate of resources and prolong the remaining service life of the mine, a case study of the Gaozhuang Coal Mine in the Zaozhuang Mining Area has been performed in this paper. Based on the specific mining geological conditions of ultra-close coal seams (#3up and #3low coal seams), their joint systematic analysis has been performed, with the focus made in the following three aspects: (i) prevention of rock burst under super-thick hard roof, (ii) deformation control of surrounding rock of roadways in the lower coal seam, and (iii) fire prevention in the goaf of working face. Given the strong bursting tendency observed in upper coal seam and lower coal seam, the technology of preventing rock burst under super-thick hard roof was proposed, which involved setting of narrow section coal pillars to protect roadways and interleaving layout of working faces. The specific supporting scheme of surrounding rock of roadways in the #3low1101 working face was determined, and the grouting reinforcement method of local fractured zones through Marithan was further proposed, to ensure the deformation control of surrounding rock of roadways in lower coal seams. The proposed fire prevention technology envisaged goaf grouting and spraying to plug leaks, which reduced the hazard of spontaneous combustion of residual coals in mined ultra-close coal seams. The technical and economic improvements with a direct economic benefit of 5.55 million yuan were achieved by the application of the proposed comprehensive technical support. The research results obtained provide a theoretical guidance and technical support of safe mining strategies of close coal seams in other mining areas.

Study on the Prediction Method of Tunnel Surrounding Rock Pressure Based on the Theory of Progressive Destruction

2012 ◽  
Vol 446-449 ◽  
pp. 1432-1436
Author(s):  
Suo Wang
Keyword(s):  
Rock Pressure ◽  
Characteristic Curve ◽  
Prediction Method ◽  
Surrounding Rock ◽  
Progressive Damage ◽  
Tunnel Excavation ◽  
Practical Engineering ◽  
Surrounding Rock Pressure ◽  
The Relationship ◽  
Rock Parameters

In order to predict tunnel surrounding rock pressure, this paper puts forward a series of dynamic numerical simulative model on the tunnel excavation. According to the change of rock damage in the construction program, it adjusts dynamically the mechanical material parameters of surrounding rock. So the model achieves the purpose which is controlling and simulating the process of tunnel progressive damage. In accordance with the numerical simulative results, it analyzes the relationship between the rock parameters with the plastic strain, radial displacement. Then this paper proposes a prediction method of tunnel surrounding rock pressure based on the theory of the progressive damage and method of characteristic curve. Finally, it compares the pressure on the numerical simulative models with on the site date, and it proves that the prediction method has practical engineering value.

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.

PROGRESS IN PHYSIOLOGICAL ACOUSTICS

2013 ◽  
Vol 13 (05) ◽  
pp. 1340007 ◽  
Author(s):  
FUYIN MA ◽  
JIU HUI WU ◽  
HAIYUN HOU
Keyword(s):  
Experimental Testing ◽  
Critical Band ◽  
Simulation Methods ◽  
Acoustic Model ◽  
Analysis Method ◽  
Biological Factors ◽  
Physical Acoustics ◽  
Physiological Acoustics ◽  
Numerical Simulation Methods ◽  
Evaluation Survey

Physiological acoustics is a very hot topic in modern acoustic research, which is to study the hearing mechanism and the utterance of both humans and animals. It could be divided into two main aspects: physical acoustics of the ear and physiological acoustics. In physiological acoustics, there are some common research methods, such as objective experimental testing, subjective feelings evaluation survey statistical method, building the physical acoustic model and numerical simulation methods, etc. The authors are researching the accurate mathematical model of equal loudness curves, critical band and masking effects, by applying the holographic concept with several biological factors which are required to build a standard model. The cochlear emission information should be extracted from wavelet analysis method and two hearing protection technologies are being developed by band shielding.

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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