Strata Movement Around Large Mining Height Face Area with Fully Mechanized Method in Steeply Dipping Thick Seam

Wu, Yongping
Organization: International Conference on Ground Control in Mining
Pages: 7
Publication Date: Jan 1, 2014
The steeply dipping coal seams in this paper refer to those with the angle of inclination ranging from 35° to 55°. The reserves of the steep coal seams account for approximately 15%~20% of the total coal reserves in China. In the past 12 years, the top-coal caving mining method had been used to mine the steeply dipping thick (11.5-16.4 ft or 3.5-5.0m) coal seams. However, the mining process of top coal caving is complex with low recovery rate and nearly 30% of coal was wasted. Those problems can be solved by using the single pass large mining height (11.5-16.4 ft or 3.5-5.0m) method. But the movement of the overlying strata around the mining face area of large mining height is complex and it is hard to control the stability of ?rock-shield support? system. Therefore, field measurement, numerical simulation and physical (similarity material) simulation methods were used simultaneously to analyze the strata movement, roof structure and rock-shield support interaction characteristics. The results indicate that strata movement, which is the same as mining the steeply dipping seams with conventional mining heights, is asymmetrical about the dipping direction of the face; deformation, failures, and movement of the surrounding rocks are more intense; the roof weighting interval decreases; the weighting intensity increases significantly; and face sloughage occurs frequently. In the gob, the space for sliding and rolling of the roof increases; the broken main roof tends to form an anti-dip pile structure; the backfilling and compactness of broken roof increase at the lower portion of the face, thereby inducing significant unbalance in stress distribution between the upper and lower portions of the face. The overlying strata above the face form a multi-level step structure. The characteristics of contact and loading of roof-shield support system are more complex. The range of shield load variation is larger, and interaction between shield supports occurs frequently. Anti-toppling and anti-sliding devices at the face become more difficult to implement. The research results provide a theoretical basis for the mining practices in the steeply dipping thick seams with a large mining height. The practice in panel 25221 of 2130 coal mine indicates that the accident rates have been greatly reduced and good technical and economic benefits have bee realized.
Full Article Download:
(1785 kb)


Additional chapters/articles from the SME-ICGCM book 33rd International Conference on Ground Control in Mining

Development of the 3D Numerical Modeling of Roof Bolts for S
Development and Application of the TT Anti?Friction Washer f
A Comparison Between ARMPS and the New ARMPS?LAM Programs
Multi?stage Testing Procedures, Verification, and Results fo
The Caterpillar HW300 Quickscan
Underground Mining Technology in Chinese Coal Mines
Rock Characterization Using Time - Series Classification Alg
Ground Control in the Underground Coal Mines of Colombia
Investigating the Contributing Factors to Rib Fatalities Thr
Analyses of De-Confinement Mechanisms of Unstable Failures i
Photogrammetric Monitoring of Rock Mass Behavior in Deep Vei
Development of An Enhanced Methodology for Ground Movement P
Estimating Coal Strength Based on Historical Laboratory Test
Experimental Observations and Interpretations on Fracture Ne
Overburden Failure Characteristics of Extra?Thick Seam Using
FlexKnot: An Innovation in Roof and Rib Surface Control
Learning Our Geotechnical Limits and Pushing Our Longwalls T
Three Dimensional Analysis of Strain and Ground Surface Disp
Use of a Plate Loading Device to Quantitatively Evaluate Wea
Ground Control Design Considerations for Reducing Longwall?I
Mechanics of Horizontal Movements Associated with Coal Mine
Roof Geotechnical Properties for Roof Control Purposes in Il
Update: Analysis and Case Study of Impact?Resistant Steel Se
The Implementation of Rock Mechanics Into a Multiple Level L
A Case Study for Multiple Seam Calibration of LaModel in Bum
A Liquid Settlement System for Measuring Roof Sag During Dev
Ground Response As a Longwall Advances Into a Backfilled Rec
A Case Study of a Low Overburden Longwall Recovery with Pre?
To What Extent the Mechanical Properties of Coal Play Role i
Mine Water Vs. Drinking Water?Technical Execution and Legal
Mitigation of a Massive Sandstone Channel?s Impact on Longwa
Study on the Modified Model of Probability Integra Method
Multi?Seam Mining Over Old Workings with Small Pillars - A C
Development of Mechanized Ground Support Installation Equipm
Understanding and Optimizing the Performance of Passive Prim
Validation of Overburden Failure Zone in Complex Extra Thick
The Impact Factors of Overburden Movement in Longwall Mining
Fiber Reinforced Polymer Rockbolts for Ground Control in a S
Introduction of a Measurement Based Ground Control Managemen
Application of Various Probing Methods for Rock Characteriza
Risk Analysis and Risk Ranking in Tunneling: A Case Study
Development of Road Header Roof Bolting Module
Combined Effects of Rock Bedding Orientation and Topography
Challenges of Room and Pillar Mining at 900 M Depths in the
Sandy Creek Waterfall?Case Study of Successful Management of
Overburden Strata Movement for the Longwall Mining of Shallo
Rock Slope Stability Comparison Between Deterministic and Pr
Stability of a Gateroad Used Simultaneously for Two Retreati
Meeting the Challenges of Floor and Sidewall Strata Control
Strata Control Investigations During Fully Mechanized Coal P
Strata Movement Around Large Mining Height Face Area with Fu
A Case Study of Topography?Related Stress Rotation Effects o
Introduction of a New Superior Coating on Ground Support Pro
Suspension Designs Required in the Logical Framework
A Novel and Effective Method to Develop Tension in a Roof Bo
Time Dependent Mining Induced Subsidence Measured by Differe
Tracking and Tracing in Terms of Transportation Logistics of