Geomechanics Research with Critical Depth Prediction and Surface Subsidence Range Controlling

2014 ◽  
Vol 952 ◽  
pp. 155-160
Author(s):  
Jian Ming Zheng ◽  
Feng Yu Ren ◽  
Lie Xian Tang
Keyword(s):  
Friction Angle ◽  
Surface Subsidence ◽  
Control Surface ◽  
Critical Depth ◽  
Deep Mining ◽  
Depth Prediction ◽  
Rock Stability ◽  
Bulk Solid ◽  
Support Force ◽  
And Control

Traditional subsidence range prediction by stagger angle doesn’t adapt to production situation in deep mining, the angle is usually large. Analyze the lateral support force of the moving bulk solid in the subsidence pit based on maintaining sidewall rock stability of subsidence pit. While bulk solid thickness of subsidence pit is not less than critical bulk solid column, the active pressure and passive pressure of bulk solid prevent the scaling of sidewall rock together. By analyzing the measured data of subsidence range of Xishimen mine, the height of critic bulk solid column relates to stability of rock, sidewall angle of goaf, internal friction angle, and rock loose coefficient. In deep mining, that filling subsidence pit with waste rock can lower the critical depth and control surface subsidence range.

Study on the Structure Model and Controlling Method of Subsidence in Flat Seam and Deep Mining

2006 ◽  
Vol 306-308 ◽  
pp. 1403-1408 ◽  
Author(s):  
Chong Ge Wang ◽  
Wei Zhong Chen ◽  
Liyou Pan
Keyword(s):  
Research Work ◽  
Surface Subsidence ◽  
Deep Mining ◽  
Global Positioning ◽  
Coal Wall ◽  
The Face ◽  
Surface Subsidence Control ◽  
The Common ◽  
And Control ◽  
Overlying Strata

The stratum movement and surface subsidence is considered as a whole system in the research work. The key of the surface subsidence control lies first in having thorough knowledge of the dynamic changeable of the overlaying strata movement as the face advances so as to establish the corresponding structure mechanics subsidence model in flat seam and deep mining. The common characteristic of stratum movement and the development procedure of crack arch are described in this paper. The structure constituents of subsidence and their influencing factors are also analyzed. Meanwhile, the surface subsidence is determined by the compressing of coal wall and the bending of the overlying strata. Based on the ground observation by the global positioning system, the boundary angle and the motion angle are determined. Furthermore, according to the research law, one can predict and control the surface subsidence damages for the special geologic conditions.

scholarly journals Fuzzy x- and s Control Charts: A Data-Adaptability and Human-Acceptance Approach

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Ming-Hung Shu ◽  
Dinh-Chien Dang ◽  
Thanh-Lam Nguyen ◽  
Bi-Min Hsu ◽  
Ngoc-Son Phan
Keyword(s):  
Surface Roughness ◽  
Control Charts ◽  
Fuzzy Numbers ◽  
Control Surface ◽  
Process Conditions ◽  
Fuzzy Data ◽  
Size Condition ◽  
Resolution Identity ◽  
And Control ◽  
Control Limits

For sequentially monitoring and controlling average and variability of an online manufacturing process, x¯ and s control charts are widely utilized tools, whose constructions require the data to be real (precise) numbers. However, many quality characteristics in practice, such as surface roughness of optical lenses, have been long recorded as fuzzy data, in which the traditional x¯ and s charts have manifested some inaccessibility. Therefore, for well accommodating this fuzzy-data domain, this paper integrates fuzzy set theories to establish the fuzzy charts under a general variable-sample-size condition. First, the resolution-identity principle is exerted to erect the sample-statistics’ and control-limits’ fuzzy numbers (SSFNs and CLFNs), where the sample fuzzy data are unified and aggregated through statistical and nonlinear-programming manipulations. Then, the fuzzy-number ranking approach based on left and right integral index is brought to differentiate magnitude of fuzzy numbers and compare SSFNs and CLFNs pairwise. Thirdly, the fuzzy-logic alike reasoning is enacted to categorize process conditions with intermittent classifications between in control and out of control. Finally, a realistic example to control surface roughness on the turning process in producing optical lenses is illustrated to demonstrate their data-adaptability and human-acceptance of those integrated methodologies under fuzzy-data environments.

Model reduction of aerothermodynamic for hypersonic aerothermoelasticity based on POD and Chebyshev method

2018 ◽  
Vol 233 (10) ◽  
pp. 3734-3748
Author(s):  
Yan Xiaoxuan ◽  
Han Jinglong ◽  
Zhang Bing ◽  
Yuan Haiwei
Keyword(s):  
Computational Cost ◽  
Maximum Error ◽  
Control Surface ◽  
Alternative Approach ◽  
Average Maximum ◽  
Optimization And Control ◽  
Efficient Alternative ◽  
Computational Fluid Dynamics Cfd ◽  
And Control ◽  
Proper Orthogonal

Accurate modeling of aerothermodynamics with low computational cost takes on a crucial role for the optimization and control of hypersonic vehicles. This study examines three reduced-order models (ROMs) to provide a reliable and efficient alternative approach for obtaining the aerothermodynamics of a hypersonic control surface. Coupled computational fluid dynamics (CFD) and computational thermostructural dynamics (CTSD) approaches are used to generate the snapshots for ROMs considering the interactions between aerothermodynamics, structural dynamics and heat transfer. One ROM adopts a surrogate approach named Kriging. The second ROM is constructed by the combination of Proper Orthogonal Decomposition (POD) and Kriging, namely, POD-Kriging. The accuracy of Kriging-based ROM is higher than that of POD-Kriging-based ROM, but the efficiency is lower. Therefore, to address the shortcomings of the above two approaches, a new ROM is developed that is composed of POD and modified Chebyshev polynomials, namely, POD-Chebyshev. The ROM based on POD-Chebyshev has the best precision and efficiency among the three ROMs and generally has less than 2% average maximum error for the studied problem.

Effects of Hull and Control Surface Roughness on Ship Maneuvering

2020 ◽  
pp. 1-10
Author(s):  
John C. Daidola
Keyword(s):  
Surface Roughness ◽  
Equations Of Motion ◽  
Control Surface ◽  
Ship Maneuvering ◽  
Single Screw ◽  
Operation And Maintenance ◽  
Hydrodynamic Derivatives ◽  
Turning Maneuver ◽  
And Control ◽  
Surface Vessel

The effects of hull roughness on ship maneuvering characteristics are investigated. The hydrodynamic derivatives in the equations of motion for surface vessel maneuvering are modified to incorporate roughness of the hull and rudder. Vessel lifetime roughness profiles are postulated based on construction, coatings, operation, and maintenance for a vessel life of 25 years. These are then applied to the turning maneuver for single screw cargo ships with block coefficients from .60 to .80. The implications for naval missions are discussed.

Analysis and Control of Layer Deformation Induced by the Densely Arranged Large Diameter Underground Steel Tubes Jacking with NTR Method

2015 ◽  
Vol 744-746 ◽  
pp. 1010-1014
Author(s):  
Chun Fu Jin ◽  
Peng Niu ◽  
Yong Sheng Zhao ◽  
Xuan Wang
Keyword(s):  
Surface Deformation ◽  
Large Diameter ◽  
Influence Factors ◽  
Surface Subsidence ◽  
The Finite Element Method ◽  
Steel Tubes ◽  
Steel Pipes ◽  
Pipe Jacking ◽  
And Control ◽  
Layer Deformation

Combined with the finite element method (FEM) and the field data of Shenyang Metro NTR engineering for pipe jacking process, the variation of surface deformation and influence factors of NTR construction are systematically analyzed. The result is shown that the curves of the lateral surface subsidence produced by pipe jacking process are accord with the normal distribution curves put forward by Peck .When the top steel pipes are jacked , the surface subsidence develops rapidly and the rate of deformation is larger. In addition , grouting behind the wall and the sequence of the pipe jacking all have a greater impact on the deformation of the layer.

scholarly journals Surface Subsidence Prognosis above an Underground Longwall Excavation and Based on 3D Point Cloud Analysis

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 82 ◽  
Author(s):  
Andrej Pal ◽  
Janez Rošer ◽  
Milivoj Vulić
Keyword(s):  
Rock Mass ◽  
Longwall Mining ◽  
Underground Mining ◽  
Point Clouds ◽  
Surface Subsidence ◽  
Protection Measures ◽  
Engineering Research ◽  
3D Point Clouds ◽  
Research Activities ◽  
And Control

Impacts of underground mining have been reduced by continuous environmental endeavors, scientific, and engineering research activities, whose main object is the behavior and control of the undermined rock mass and the subsequent surface subsidence. In the presented Velenje case of underground sublevel longwall mining where coal is being exploited both horizontal and vertical, backfilling processes and accompanying fracturing in the coal layer, and rock mass are causing uncontrolled subsidence of the surface above. 3D point clouds of the study were acquired in ten epochs and at excavation heights on the front were measured at the same epochs. By establishing a sectors layout in the observational area, smaller point clouds were obtained, to which planes were fitted and centroids of these planes then calculated. Centroid heights were analyzed with the FNSE model to estimate the time of consolidation and modified according to excavation parameters to determine total subsidence after a certain period. Proposed prognosis approaches for estimating consolidation of active subsidence and long term surface environmental protection measures have been proposed and presented. The C2C analysis of distances between acquired 3D point clouds was used for identification of surface subsidence, reclamation areas and sink holes, and for validation of feasibility and effectiveness of the proposed prognosis.

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