Optimization of Reasonable Interval of Parallel Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 1550-1553
Author(s):  
Li Guo ◽  
Hong Fang Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Calculation ◽  
Stability Analysis ◽  
Stress Distribution ◽  
Simulation Models ◽  
Surrounding Rock ◽  
Major Task ◽  
Parallel Tunnel ◽  
Single Stress

To acquire the stress distribution of surrounding rock is the important mean of stability analysis and the major task of numerical simulation. But the breaking probability cannot be expressed by the magnitude of single stress straightly. Based on the Mohr-Coulomb theory, coefficient S was deduced and used for further treatment of the result of numerical simulation. Models of parallel tunnel with different interval were building and analyzed. The different distributions of coefficient S were compared and analyzed after numerical calculation. The more reasonable tunnel interval was given, which can be a reference for optimization of design of similar projects.

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

scholarly journals Analysis on Characteristics of Surrounding Rocks of Roadway and Bearing Structure Based on Stress Regulation

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Ruofei Zhang ◽  
Guangming Zhao ◽  
Xiangrui Meng ◽  
Jian Sun ◽  
Wensong Xu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Mechanical Characteristics ◽  
Axial Ratio ◽  
Maximum Principal Stress ◽  
Surrounding Rock ◽  
Rock Stress ◽  
Rock Reinforcement ◽  
Bearing Structure ◽  
Surrounding Rock Stress

To address the prominent status of great deformation and difficult maintenance of the roadway under high stresses, this study investigated the mechanical characteristics of surrounding rocks and bearing structural stability in a roadway under adjustment and redistribution of stresses through theoretical analysis, numerical simulation, and engineering field test. Stability forms of the bearing structure of roadway surrounding rocks were analyzed by using the axis-changing theory from the perspectives of surrounding rock, mechanical properties of roadways, surrounding rock stress distribution, and mechanical mechanism of the bearing structure. It is suggested that the surrounding rock stress distribution state is improved and the bearing structure is optimized through unloading and reinforcement construction. A mechanical model of roadway excavation was constructed to analyze the influences of excavation spatial effect on the stress releasing and bearing structure of surrounding rocks. A rock postpeak strain softening and dilatation model was introduced to investigate the mechanical characteristics of the surrounding rock mass in the rupture residual zone and plastic softening zone in a roadway. Moreover, we analyzed the influences of unloading and reinforcement construction on the stress path and mechanical characteristics of the rock unit model, which disclosed the adjustment mechanism of the bearing structure of surrounding rocks by the failure development status of rocks. A numerical simulation on the distribution of surrounding rock stress fields and adjustment features of the bearing structure after roadway excavation and unloading and reinforcement construction was carried out by using the FLAC3D program. Results demonstrate that the unloading construction optimizes the axial ratio of spatial excavation in a roadway and the reinforcement zones on both sides are the supporting zones of the bearing structure. Moreover, the ratio between the distance from two side peaks to the roadway sides and the distance from the roof and floor peaks to the excavation space is equal to the coefficient of horizontal pressure. In other words, the final collapse failure mode of surrounding rock is that the long axis of the excavation unloading space points to the same direction with the maximum principal stress of the primary rock. Reinforcement forces the surrounding rocks to form a “Ω-shaped” bearing structure, which is in favor of the long-term maintenance of the roadway.

Stability Analysis of Tunnel during the Excavation Based on ANSYS

2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress Condition ◽  
Stability Control ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Rock Stability ◽  
Before And After ◽  
The Stability

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.

The Study of Stress Distribution Law of Roadway Surrounding Rock Heading Advancing Coal Face

2011 ◽  
Vol 361-363 ◽  
pp. 166-170 ◽  
Author(s):  
Jun Ling Hou
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Theoretical Foundation ◽  
Dynamic Pressure ◽  
Surrounding Rock ◽  
Rock Stress ◽  
Coal Face ◽  
Distribution Law ◽  
Computer Numerical Simulation ◽  
Surrounding Rock Stress

In background of the geological engineering and the mining technical conditions of ZhangJi coal mine 17258 fully-mechanized face and rail roadway of 1724 (1) fully-mechanized face,by the field observation and computer numerical simulation studying the stress distribution law of roadway surrounding rock heading advancing coal face.Obtain the influence scope of the dynamic pressure along coal seam trend and tendency, the stress peaks position, perturbation boundary angle of dynamic pressure,and the surrounding rock stress distribution law of roadway excavating in the zone of the stress concentration and stress reduced area. Provides the theoretical foundation for roadway layout under similar conditions.

scholarly journals Study on strata behavior law of deep inclined coal seam

2021 ◽  
Vol 248 ◽  
pp. 03031
Author(s):  
Chen Zhengwen
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Coal Seams ◽  
Working Face ◽  
Support Resistance ◽  
Strata Behavior ◽  
The Law ◽  
Surrounding Rock Deformation

In order to understand and grasp the law of roof pressure on the working face of deep inclined coal seams, the law of support resistance distribution, the law of leading support stress distribution and the law of surrounding rock deformation of the two roadways, the 94101 working face of Zhangshuanglou Coal Mine was taken as the engineering background. Through a combination of field measurement, numerical simulation, theoretical analysis, etc, this paper analyzes the laws of roof migration and rock pressure manifestation in deep inclined coal seams.

The Numerical Study of the Stability of Roadway Seeping in the Roof

2012 ◽  
Vol 178-181 ◽  
pp. 1293-1296
Author(s):  
Feng Zhen Liu ◽  
Wei Guo Qiao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Plastic Zone ◽  
Numerical Study ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Key Factors ◽  
Roadway Stability ◽  
The Stability ◽  
Roadway Deformation

Seepage in the roof is one of main reasons resulting softening rock and roadway deformation, in order to make sure about the influence of seepage on the roadway stability, we established corresponding models by using numerical simulation software, and analyzed the stress distribution, the deformation of surrounding rock, and the distribution range and shape of the plastic zone, the results show that water is one of the key factors to influence the stability of roadway, seepage makes the strength of surrounding rock sharply reduce, and the roof, two ribs and floor appear serious deformation.

Integrated Design and Numerical Simulation of Stiffened Panels Including Friction Stir Welding Effects

2013 ◽  
Vol 554-557 ◽  
pp. 2237-2242 ◽  
Author(s):  
Rui Miguel Ferreira Paulo ◽  
Pierpaolo Carlone ◽  
Robertt A.F. Valente ◽  
Filipe Teixeira-Dias ◽  
Gaetano S. Palazzo
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Friction Stir Welding ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Ultimate Load ◽  
Simulation Models ◽  
Residual Stress Distribution ◽  
Stiffened Panels ◽  
Friction Stir

Stiffened panels are usually the basic structural building blocks of airplanes, vessels and other structures with high requirements of strength-to-weight ratio. They typically consist of a plate with equally spaced longitudinal stiffeners on one side, often with intermediate transverse stiffeners. Large aeronautical and naval parts are primarily designed based on their longitudinal compressive strength. The structural stability of such thin-walled structures, when subjected to compressive loads, is highly dependent on the buckling strength of the structure as a whole and of each structural member. In the present work, a number of modelling and numerical calculations, based on the Finite Element Method (FEM), is carried out in order to predict the ultimate load level when stiffened panels are subjected to compressive solicitations. The simulation models account not only for the elasto-plastic nonlinear behaviour, but also for the residual stresses, material properties modifications and geometrical distortions that arise from Friction Stir Welding (FSW) operations. To construct the model considering residual stresses, their distribution in FSW butt joints are obtained by means of a numerical-experimental procedure, namely the contour method, which allows for the evaluation of the normal residual stress distribution on a specimen section. FSW samples have been sectioned orthogonally to the welding line by wire electrical discharge machining (WEDM). Displacements of the relaxed surfaces are then recorded using a Coordinate Measuring Machine and processed in a MATLAB environment. Finally, the residual stress distribution is evaluated by means of an elastic FE model of the cut sample, using the measured and digitalized out-of-plane displacements as input nodal boundary conditions. With these considerations, the main goal of the present work will then be related to the evaluation of the effect of FSW operations, in the ultimate load of stiffened panels with complex cross-section shapes, by means of realist numerical simulation models.

scholarly journals Numerical Simulation of Surrounding Rock Stress under Different Overlying Strata Combinations in Sijiazhuang Mine

2018 ◽  
Vol 53 ◽  
pp. 03031
Author(s):  
Jun He
Keyword(s):  
Numerical Simulation ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Theoretic Model ◽  
Rock Stress ◽  
Pressure Relief ◽  
Surrounding Rock Stress ◽  
Overlying Strata

Sijiazhuang coal mine is taken as an example in this paper. Both the theoretic model and the numerical simulation are carried out to analyze the stress distribution regularity on the surrounding rock of stope face under different overlying strata combinations by using discrete element method. Under different combinations of the overlying strata, the results indicate that the regularity of stress distribution around stope face is roughly the same, i.e. the stress concentration of different degree appears in both ends, and the region of pressure relief exist above the stope face. Furthermore, destruction degree of the roof in stope face is different under various overlying strata combinations. On the eve of the first weighting, the different combinations present different phenomenon of concentration, especially the soft-hard-soft combination and hard-soft-hard combination.

scholarly journals Instability Analysis and Reinforcement Support Technology of Coal-Rock Interbed Roadway in Gaojiazhuang Coal Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chaolin Liu ◽  
Guohua Zhang
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Distribution Characteristics ◽  
Control Effect ◽  
Ultrasonic Detection ◽  
Wide Range ◽  
Surrounding Rock Deformation

In order to effectively solve a series of problems such as the difficulty of coal and rock interbed roadway support in Gaojiazhuang Coal Mine and get a scientific and reasonable optimization scheme of surrounding rock support, theoretical analysis, numerical simulation, ultrasonic detection, field-effect test, and other means are adopted to analyze the instability of coal and rock interbed roadway. The results show that the interbedded roadway has weak interbedded cementation, and its ore pressure is more intense due to the influence of its interbedded weak structural plane. Based on Mohr’s strength envelope principle, it is proposed that horizontal stress is the main factor that causes a wide range of shear displacement, penetration crack, and surrounding rock failure of the roof of this kind of roadway. Through the finite element numerical simulation analysis, the deformation and failure law, stress distribution characteristics, and failure area distribution characteristics of coal and rock interbedding roadway surrounding rock are theoretically revealed, and the control effect of different support schemes on roadway surrounding rock deformation is greatly different. Based on the ultrasonic detection technology, it is proved that the roadway side failure has strong zoning characteristics, and the failure range and stress distribution range of the surrounding rock of the belt roadway in the 2103 working face of Gaojiazhuang Coal Mine are detected. Finally, the coupling strengthening support scheme combining prestressed anchor cable and bolt is proposed. The engineering application and the observation of surrounding rock deformation show that the reinforced support technology can effectively enhance the stability of the surrounding rock of the interbed roadway in Gaojiazhuang Coal Mine, and it has a good reference for the surrounding rock conditions of this kind of roadway.

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