scholarly journals Three-Dimensional Physical Simulation and Control Technology of Roof Movement Characteristics in Non-Pillar Gob-Side Entry Retaining by Roof Cutting

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xinzhu Hua ◽  
Guanfeng Chang ◽  
Xiao Liu ◽  
Bingjun Sun ◽  
Sen Yang ◽  
...  
Keyword(s):  
Simulation Experiment ◽  
Physical Simulation ◽  
Three Dimensional ◽  
Engineering Application ◽  
Key Strata ◽  
Rock Structure ◽  
Geological Conditions ◽  
Support Resistance ◽  
And Migration ◽  
Roof Deformation

An overlying rock structure plays a key role in controlling the roof deformation of nonpillar gob-side entry retaining by roof cutting. On the bases of the actual geological conditions of II 632 Haulage Roadway at the Hengyuan coal mine, a similar three-dimensional simulation experiment of roof precutting is conducted. Thereafter, the caving characteristics and migration law of the roof strata in the strike and dip directions are obtained. Moreover, the roof of the retained roadway and key strata of the goaf can form a hinge structure of the key blocks. By monitoring the deformation of the surrounding rock and stress distribution of the roof, the skew deformation characteristics of roadway roof are obtained. By observing the borehole peeping technology, the roof subsidence near the goaf is determined to be greater than that of the solid coal side, and the roof subsidence of the gob-side entry retained by roof cutting is greater than that of the floor heave and two sides approaching. Results of the three-dimensional similar simulation experiment indicate that the mechanical structure model of the key block of the retained roadway roof is constructed, and the mechanical analytical solution of the required support resistance of the retained roadway roof is obtained. This study proposes the constant resistance and large deformation anchor cable reinforcement support method to control the roof deformation of the retaining roadway. Through engineering application, the maximum value of the roof and floor movement of the retained roadway is stable at approximately 650 mm. The retained roadway can meet the demand of the next mining face.

scholarly journals Study and Application of Roof Cutting Pressure Releasing Technology in Retracement Channel Roof of Halagou 12201 Working Face

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Ma Xingen ◽  
He Manchao ◽  
Wang Yajun ◽  
Zhang Yong ◽  
Zhang Jiabin ◽  
...  
Keyword(s):  
High Stress ◽  
Hydraulic Support ◽  
Working Face ◽  
Geological Conditions ◽  
Support Resistance ◽  
Cutting Effect ◽  
Mining Pressure ◽  
Cutting Height ◽  
First Time ◽  
Roof Deformation

The retracement channel roof cutting (RCRC) technology can change the overburden structure actively by cutting off the roof of channel along the direction of working face tendency and make use of the gangue collapsing from roof cutting range to fill the goaf and weaken the mining pressure during the retracement process of working face. In order to solve the problems of high stress in surrounding rock and serious deformation of retracement channel in Halagou coal mine, it is the first time that the pressure releasing test is carried out on the 12201 working face by the method of the directional presplitting roof cutting in retracement channel. First, according to statics theory and energy theory, the stress state of hydraulic support and roof deformation mechanism of retracement channel are analyzed. Then the roof cutting design of retracement channel is determined according to the geological conditions of 12201 working face, and the cutting effect is analyzed by numerical simulation. Finally, the field test is carried out on the 12201 working face to verify the effect of pressure releasing by roof cutting. The result shows that, with the roof cutting design including the roof cutting height being 8m and roof cutting angle being 45°, the roof subsidence of the 12201 working face retracement channel in Halagou mine is reduced to 132.5mm, and the hydraulic support resistance is maintained at 1361KN. And there is no hydraulic support crushed; the deformation of the retracement channel is also small; namely, the effect of roof cutting for pressure releasing is obvious.

Geology Analysis and Support Scheme Design in Soft Rock Coal Mine

2012 ◽  
Vol 446-449 ◽  
pp. 1591-1595
Author(s):  
Cheng Liang Li ◽  
Zhao Yan Li
Keyword(s):  
Three Dimensional ◽  
Soft Rock ◽  
Field Investigation ◽  
Scheme Design ◽  
Design Procedures ◽  
Composition And Structure ◽  
Geological Conditions ◽  
Rock Tunnel ◽  
Construction Condition ◽  
Roof Deformation

In this paper, Dongrong mine encountered soft rock geological problems as the research object, from the field investigation, laboratory analysis, program design and numerical simulation of four aspects of the problem spread out concrete research. Combining engineering geological conditions and scene construction condition, adopt big deformation nonlinearity theory and design procedures. Study the instability of soft rock tunnel, rock mineral composition and structure. Soft rock tunnel shoring method has carried out the three-dimensional numerical simulation.Studies have shown that pre-stressed anchor supporting technology can effectively control the roof deformation, single-arch bottom floor heave phenomenon can be reduced.

Physical Simulation Experiment Research of Steam and Gas Assisted Gravity Drainage

2014 ◽  
Vol 556-562 ◽  
pp. 1464-1467
Author(s):  
Li Guo Zhong ◽  
Yan Chao Wang ◽  
Ya Qi Zhang
Keyword(s):  
High Pressure ◽  
Physical Model ◽  
Simulation Experiment ◽  
Physical Simulation ◽  
Early Stage ◽  
Three Dimensional ◽  
Gravity Drainage ◽  
Temperature And Pressure ◽  
Design And Manufacture ◽  
High Output

Aiming at the problems in the conventional SAGD production process, taking a heavy oil reservoir in Bohai oilfield for prototype, we design and manufacture a set of three-dimensional physical model which is resistance to high temperature and high pressure. Under the same temperature and pressure, using this physical model we made two sets of indoor experiments. The experimental results show that steam and gas assisted gravity drainage has the characteristics of high output at the early stage, dramatic decrease at the end compared with the SAGD mining, development effect of high pressure reservoir is good when using steam and gas assisted gravity drainage after steam and gas stimulation preheating, recovery of steam and gas assisted gravity drainage after three rounds of steam and gas stimulation preheating is improved significantly.

Simulation on Torpedo Unsteady Hydrodynamic with the Movement in the Longitudinal Plane

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang
Keyword(s):  
Three Dimensional ◽  
Engineering Application ◽  
Calculation Model ◽  
Trajectory Design ◽  
Design Calculation ◽  
Variable Speed ◽  
Accurate Calculation ◽  
Longitudinal Plane ◽  
Submerged Body ◽  
Mesh Method

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.

Analysis of migration paths in fast-ion conductors with Voronoi–Dirichlet partition

2006 ◽  
Vol 62 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Vladislav A. Blatov ◽  
Gregory D. Ilyushin ◽  
Olga A. Blatova ◽  
Nataly A. Anurova ◽  
Alexej K. Ivanov-Schits ◽  
...  
Keyword(s):  
Alkali Metals ◽  
Three Dimensional ◽  
Charge Carriers ◽  
Alkali Cations ◽  
Fast Ion Conductors ◽  
And Migration ◽  
Crystal Space ◽  
Fast Ion ◽  
Dirichlet Partition ◽  
Ion Conductors

In terms of the Voronoi–Dirichlet partition of the crystal space, definitions are given for such concepts as `void', `channel' and `migration path' for inorganic structures with three-dimensional networks of chemical bonds. A number of criteria are proposed for selecting significant voids and migration channels for alkali cations Li+–Cs+ based on the average characteristics of the Voronoi–Dirichlet polyhedra for alkali metals in oxygen-containing compounds. A general algorithm to analyze the voids in crystal structures has been developed and implemented in the computer package TOPOS. This approach was used to predict the positions of Li+ and Na+ cations and to analyze their possible migration paths in the solid superionic materials Li3 M 2P3O12 (M = Sc, Fe; LIPHOS) and Na1 + x Zr2Si x P3 − x O12 (NASICON), whose framework structures consist of connected M octahedra and T tetrahedra. Using this approach we determine the most probable places for charge carriers (coordinates of alkali cations) and the dimensionality of their conducting sublattice with high accuracy. The theoretically calculated coordinates of the alkali cations in MT frameworks are found to correlate to within 0.33 Å with experimental data for various phases of NASICON and LIPHOS. The proposed method of computer analysis is universal and suitable for investigating fast-ion conductors with other conducting components.

scholarly journals Variable Thumb Moment Arm Modeling and Thumb-Tip Force Production of a Human-Like Robotic Hand

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Taylor D. Niehues ◽  
Ashish D. Deshpande
Keyword(s):  
Physical Simulation ◽  
Three Dimensional ◽  
Force Production ◽  
Human Hand ◽  
Robotic Hand ◽  
Motion Data ◽  
Moment Arms ◽  
Musculoskeletal Structure ◽  
Thumb Motion ◽  
Force Vectors

The anatomically correct testbed (ACT) hand mechanically simulates the musculoskeletal structure of the fingers and thumb of the human hand. In this work, we analyze the muscle moment arms (MAs) and thumb-tip force vectors in the ACT thumb in order to compare the ACT thumb's mechanical structure to the human thumb. Motion data are used to determine joint angle-dependent MA models, and thumb-tip three-dimensional (3D) force vectors are experimentally analyzed when forces are applied to individual muscles. Results are presented for both a nominal ACT thumb model designed to match human MAs and an adjusted model that more closely replicates human-like thumb-tip forces. The results confirm that the ACT thumb is capable of faithfully representing human musculoskeletal structure and muscle functionality. Using the ACT hand as a physical simulation platform allows us to gain a better understanding of the underlying biomechanical and neuromuscular properties of the human hand to ultimately inform the design and control of robotic and prosthetic hands.

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