Download presentation
Published byHassan Laham Modified over 10 years ago
1
EMPIRICAL DESIGN METHODS – UBC GEOMECHANICS RESEARCH –CERM3 WORKSHOP
R. PAKALNIS - UBC
2
RELATE TO PAST PRACTICE
INTRODUCTION QUANTIFY ROCK MASS RELATE TO PAST PRACTICE PREDICTION INTRODUCTION ANALYTICAL OBSERVATIONAL EMPIRICAL UBC MINING & MINERAL PROCESS ENGINEERING SAFETY & WORKABLE GEOMECHANICS DESIGN GROUP
3
ROCK MASS STOPE DESIGN PILLAR DESIGN SPAN DESIGN SUPPORT STRESS 1998
STRUCTURE UBC MINING & MINERAL PROCESS ENGINEERING STRESS ROCK MASS 1998 GEOMECHANICS DESIGN GROUP
5
STRESS INDUCED LOAD INPUT PARAMETERS GUESTIMATE
UBC MINING & MINERAL PROCESS ENGINEERING GEOMECHANICS DESIGN GROUP
6
STRUCTURE GEOMETRY SHEAR STRENGTH SUPPORT GEOMECHANICS DESIGN GROUP
UBC MINING & MINERAL PROCESS ENGINEERING GEOMECHANICS DESIGN GROUP
7
ROCK MASS CLASSIFICATION
RMR (1976) Q - SYSTEM (1974) UBC MINING & MINERAL PROCESS ENGINEERING GEOMECHANICS DESIGN GROUP
8
STABILITY GRAPH (ELOS)
OPENING DESIGN STABILITY GRAPH (ELOS) CRITICAL SPAN CURVE
9
ELOS – EQUIVALENT LINEAR OVERBREAK SLOUGH
10
RELAXED HW A = 1 PARALLEL STRUCTURE B = 0.2, 0.3 WALL DIP C = ( 8 - 6*COS f )
11
MODIFIED STABILITY GRAPH – RADIUS FACTOR
12
RADIUS FACTOR = 1.1 X HYDRAULIC RADIUS
13
STABILITY GRAPH (ELOS)
OPENING DESIGN STABILITY GRAPH (ELOS) CRITICAL SPAN CURVE
14
SPAN DESIGN CURVE
15
WEAK ROCK MASS SEISMICITY EXTENT OF FAILURE 6ft 5ft 10ft
( ) 6ft 10ft 3ft x 3ft BOLT SPACING (0.5*10ft*5ft*3ft)/11ft3/ton= 7ton 5ft
17
PREDICTIVE TOOL SPAN ESTIMATION
3 3 1 292 CASE HISTORIES (160 STABLE, 59 POT, 73 UNSTABLE) 18 X 18 GRID - NEURAL OUTPUT (324 pts)
18
PREDICTIVE TOOL SPAN ESTIMATION
NEURAL NET RESULTS IN CONTOUR PLOT OF 1=.100% STABLE TO 3=100% UNSTABLE TRAINING ERROR = 12%
19
PILLAR DESIGN PILLAR LOAD/UCS PILLAR WIDTH/HEIGHT
UBC MINING & MINERAL PROCESS ENGINEERING GEOMECHANICS DESIGN GROUP
21
PILLAR STABILITY GRAPH
22
PILLAR STABILITY GRAPH
Wp/Hp < 1 SEISMICITY
23
GOLDCORP RED LAKE MINE 1700m below surface 47g/tonne GOLD 600 TPD
24
MEDIUM BURST POTENTIAL Pillar Stability Graph Induced Stress Criteria
BURST PRONE CRITERIA STABLE UNSTABLE FAILED LOW BURST POTENTIAL MEDIUM BURST POTENTIAL HIGH BURST POTENTIAL Pillar Stability Graph FS > 1.4 on Pillar Stability Graph 1.0 < FS < 1.4 FS<1.0 Induced Stress Criteria s 1/UCS < 0.5 0.5 < s 1/UCS < 0.6 s 1/UCS > 0.6 Pillar Geometry Wp/Hp > 3 2 < Wp/Hp < 3 Wp/Hp < 2 Observations Minor ground working, minor spalling Ground working, pillar spalling Substantial bursting * * in process of being evaluated - microseismic
25
STUDY AT QUINSAM MINE – BRITISH COLUMBIA - CANADA
26
SURFACE SUBSIDENCE OVER SHALLOW EXCAVATIONS
27
ANGLE OF CRITICAL DEFORMATION IS <10o FROM VERTICAL
STRUCTURAL CONTROL DEPTH OF CAVE AS MUCH AS 14X EXCAVATION HEIGHT
28
CONCLUSIONS CALIBRATION TO ANALYTICAL AND EMPIRICAL APPROACHES
INTERPOLATE, NOT EXTRAPOLATE KNOW THY DATABASE TOOL CALIBRATION TO ANALYTICAL AND EMPIRICAL APPROACHES MODIFIED ACCORDING TO MINE BEHAVIOUR UBC MINING & MINERAL PROCESS ENGINEERING SAFETY & WORKABLE GEOMECHANICS DESIGN GROUP
29
ACKNOWLEDGEMENT NIOSH CERM3
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.