Rock Mechanics Study Of Lateral Destressing For The Advance-And-Relieve Mining Method

Maleki, Hamid
Organization: International Conference on Ground Control in Mining
Pages: 9
Publication Date: Jan 1, 2003
The advance-and-relieve method benefits from lateral destressing associated with mining in laminated rocks and a high horizontal stress regime. This stress control method is based on measurements showing that occurrence of rock failure in the roof and floor of an entry (or caving of roof strata in a panel gob) results in redistribution of stresses in adjacent entries. By locating other entries within the shadow zone of the first entry (or gob), improvements in stability can be achieved. Numerical modeling proved useful in studying the basic mechanics of lateral relief while investigating the sensitivity of results to different geologic and mining parameters using controlled experiments. It was shown that failure of rocks near an entry results in redistribution of horizontal stress and shifting of the stress to higher horizons. Measurements from two mines are consistent in showing significant horizontal stress reductions in comparison with the far-field stress regime within the destressed zone. Although the far-field stress regime is very anisotropic, these measurements show near-equal secondary principal horizontal stresses, or perhaps a switch in orientation, as a result of destressing. Stress relief is achieved through lateral movement and relaxation of rocks along weak bedding planes toward adjacent caved zones (or softened zone). Because of cave geometry in the advancing panel, horizontal stress concentrations occur near the cave line both in front of the face and to the sides. The horizontal stress concentration reaches 1.7 times the far-field stress ahead of the face. This stress increase is significant and may cause structural damage in this zone benefiting from additional support. In the next advancing panel located within the shadow zone of the gob, horizontal stresses are significantly reduced in the roof (by 50%). Thus, the stability of future advancing panel can be improved through prudent layout designs and sequencing. The width of the relief zone is significantly influenced by the height of the softened (or cave zone) and rock mass properties.
Full Article Download:
(2699 kb)


Additional chapters/articles from the SME-ICGCM book 22nd International Conference on Ground Control in Mining (ICGCM) 22nd

Pillar Design and Roof Support for Controlling Longwall Head
Stress Analysis and Support Design for Longwall Mine-Through
The Utilisation of Numerical Modelling to Predict Water and
Longwall Roof Fall Prediction and Shield Support Recommendat
Comparison Of Multiple And Single Entry Roadways For Highly
Numerical Modeling Of Longwalls In Deep Coal Mines
The Characteristics Of Mining-Induced Fractures In Overlying
Design And Experience Of Total Extraction Room And Pillar Op
Using Site Case Histories Of Multiple Seam Coal Mining To Ad
Mining Method For Extracting An Eight Metre Coal Horizon Con
Stooping Low Safety Factor Pillars At Goedehoop Colliery
Modelling Of Pillar Stability In Room And Pillar Mines
Pillar Optimization For Initial Design And Retreat Recovery
Application Of RMT's Remote Reading Telltale System To
Rock Mechanics Study Of Lateral Destressing For The Advance-
New Tools For Roof Support Evaluation And Design
Considerations For Using Roof Monitors In Underground Limest
Mine Roof Geology Information System (MRGIS)
Imaging Ahead Of Mining With Radio Imaging Method (RIM-IV) I
Geophysics For The Detection Of Abandoned Mine Workings
Investigation Of Seam Thickness And Seam Splitting Within A
Determination Of Rock Strength Properties Using Geophysical
RQD from the Barrel to the Box: Weatherability May be a Bett
A probabilistic approach to ground support design in undergr
The Requirements of a Database to Store Geotechnical Data to
Variation of Horizontal Stresses and Strains in Mines in Bed
Geotechnical Planning Basis for the Optimization of Workings
Tensile roof failure arising from horizontal compressive str
Study of load transfer capacity of bolts using short encapsu
Intersection Stability and Tensioned Bolting
Premature Rock Bolt Failure Through Stress Corrosion Crackin
Short-encapsulation Pull Tests for Roof Bolt Evaluation at a
Field Test with Strain-gauged Friction Bolts at the Gold Hun
Directional Rock Bolt Pullout Tests as Index Tests for Estim
Eclipse Bolting System
The Application of Pre-tensioned Grouted Tendons at Harworth
Investigation into the Extent and Mechanisms of Gloving and
Developments in Improving the Standard of Installation and B
Development of Geotechnical Procedures for the Analysis of M
Recent Developments in the Use of Seismic Tomography in Long
Pumpable Roof Supports: Developing Design Criteria by Measur
Design Considerations of the Secondary Roof Support for Long
The Effect of Standing Support Stiffness on Primary and Seco
Numerical Modeling of the U1A Complex at the Nevada Test Sit
Rock Mechanics and the Analysis of Underground Mine Stabilit
A Study of Potential Fault Reactivation and Water Intrusion
The Elimination of Rock-fall Fatalities in Ontario Hardrock
Root Causes of Groundfall Related Incidents in U.S. Mining I
Analysis on the Dynamics of Mining Subsidence in Range of a
Mitigating Subsidence Influences on Residential Structures C
Influences of Longwall Subsidence on a Guyed Steel Tower - A
Surface Movement of Super-wide Longwall Panels Using Top-coa
New Approach to Evaluate the Stability of Yield Pillars
Experimental Study of Acoustic Emission Characteristics for