Time-dependent Behavior of Immediate Weak Floor Strata from an Illinois Coal Mines

Chugh, Y. P.
Organization: International Conference on Ground Control in Mining
Pages: 15
Publication Date: Jan 1, 1987
The paper discusses laboratory and field studies to analyze time-dependent deformation behavior of immediate weak floor strata in an Illinois coal mine. In the laboratory, core samples of the immediate floor strata were subjected to incremental creep tests under unconfined compressive stress. Both axial and lateral creep deformations were recorded. Time-dependent behavior was reasonably characterized by a Burger model with one Kelvin-Voigt unit. The elastic and viscous parameter8 of the model were found to be stress-dependent, but in the range of 40% to 80% of the failure stress, the effect of stress was relatively small. Therefore, a linear visco-elastic model was developed to represent the laboratory time-dependent behavior of immediate floor strata. Such a model may be acceptable for the design of partial extraction mining systems having extraction ratios of 40% to 60%. Field observations of roof-floor convergence (floor heave) at the mine also indicated a time-dependent behavior similar to that observed in the laboratory. Field time-dependent behavior was also characterized in terms of a Burger model with one Kelvin-Voigt unit to obtain scaling factors between the field and laboratory parameters. This approach should help in predicting likely floor heave in the mine based on laboratory creep tests. It was concluded that additional studies in the field are required to arrive at more reliable correlations between the two sets of parameters.
Full Article Download:
(2868 kb)

Additional chapters/articles from the SME-ICGCM book Proceedings 6th International Conference on Ground Control in Mining (ICGCM) 6th

Microseismic Monitoring of Mountain Bumps and Bounces: A Cas
Factors Influencing the Occurrence of Coal Pillar Bumps at
Longwall Pace Bursts and Inadequate Caving: A Came Study
Mine Layout Deign for Coal Bump Control
The Strong Outbursts of Coal and Gas in Coal Mines in China
Bock Bursts Occurrence. in the Coeur D'Alene Mining Dis
A History of Bock Burst Research in the Coeur D'Alene M
Chemical Destressing to Alleviate Rockbursts
Rockburst Control Measures at INCO's Creighton Mine
Prevention. Control and Management of Coal and Gas Outbursts
Application in Design for Close Proximity Multi-Seem Mining
Geologic Conditions Affecting Mineability in the Jane Mine.
Analysis of Cutter Roof Using the Boundary Element Method
A Novel Ground Control Program at Plateau Mining Company
Evaluation of Anchorage Integrity for Grouted Bolts in Weak
STRATA III ? A Full-Spectrum Roof Control Concept
Study of Ground Movement Over a Longwall Mine
Field Measurements of Overburden and Chain Pillar Response t
A Method for Sizing Longwall Pillars Based on Field Measurem
Aspects of Chain Pillar Design in Relation to Longwall Minin
The Initial Collapse of the Overburden Over Longwall Panels
Monitoring and Prediction of Ground Movements Above Undergro
Mechanisms of Chimney Subsidence Over Abandoned Coal Mines
Time-dependent Behavior of Immediate Weak Floor Strata from
The Significance of Specimen Stiffness and Post Yield Charac
Frictional Properties of Rock Applied to Mining Excavations
Ice Pillars, Packwalls, and Brattices
Investigation of Subsidence Over AML: A Case Study
Deign of Support System for Mining Tunnels in Carboniferous
Support of Tunnels in South African Gold Mines
The Stress Measurement and Underground Engineering
Field Measurements Of Overburden And Chain Pillar Response T