Numerical Modeling of the U1A Complex at the Nevada Test Site: Model Development and Comparison of Different Drift Mining Options

Zipf, R. Karl
Organization: International Conference on Ground Control in Mining
Pages: 10
Publication Date: Jan 1, 2003
Stress analysis programs such as MULSIM/NL, LAMODEL, MinSim 2000, and EXAMINE TAB are used in the mining industry to analyze stresses and displacements in coal mines, platinum mines, gold reefs, and tabular-type deposits. These relatively simple numerical models can efficiently simulate yielding and failure of a rock mass near a mine opening and subsequent stress transfer. The main input parameters for these models are a family of nonlinear stress-strain curves for the in-seam material. For many applications of these models, such as in coal mining, extensive field measurements and observations exist from which to estimate these stress-strain curves and calibrate the numerical models; however, such measurements are lacking for other types of mines. A three-step method is presented to determine nonlinear stress¬strain curves for boundary-element (BE) programs used in many mining applications. The method requires a suite of laboratory¬scale strength tests at various confining pressures. Note that this analysis uses laboratory-measured strength and modulus properties of alluvium. The dependency of the mechanical properties of alluvium on scale has not been established, although more tests are being planned. However, it is believed that the relative comparisons performed are valuable regardless of scale effects. First, the FLAC2D computer program is used to model the laboratory tests and determine cohesion (c) and friction angle (0) for a Mohr-Coulomb material model. Second, another FLAC2D model uses the c and 0 values to calculate vertical stress and strain around a single opening in the rock mass. This model calculates the stress-strain path of points at various distances from the opening boundary. Finally, based on these stress-strain paths, the stress-strain curves needed for a BE analysis are derived. This three-step method was demonstrated in a large, flat-lying underground test facility in very weak rock. The BE analyses agreed well with observations of failure at the test facility and provided a basis for evaluating the behavior of alternative layouts.
Full Article Download:
(2601 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