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Rock Mechanics for TunnelingDiscrete Fracture Approach
Rock Mechanics for TunnelingRock Mechanics for TunnelingDiscrete Fracture ApproachDiscrete Fracture Approach
Dr. William Dershowitz
Dept of Civil EngineeringUniversity of Washington
FracMan Technology Group
Golder Associates Inc
Rock Tunnel Design Using Q-SystemRock Tunnel Design Using QRock Tunnel Design Using Q--SystemSystem
after Hoek, 2000
Rock Tunnel Design Using Q-SystemRock Tunnel Design Using QRock Tunnel Design Using Q--SystemSystem
after Hoek, 2000
Hallandsås Tunnel: Excitement Under (and above) GroundHallandsHallandsååss Tunnel: Excitement Under Tunnel: Excitement Under (and above) Ground(and above) Ground
Hallandsås: Swedish Tunnel DisasterHallandsHallandsååss: Swedish Tunnel Disaster: Swedish Tunnel Disaster
Hallandsås Tunnel: Original Development by Drill and Blast with Grouting
HallandsHallandsååss Tunnel: Original Tunnel: Original Development by Drill and Blast with Development by Drill and Blast with GroutingGrouting
Structurally Controlled Tunnel StabilityWedge FormationStructurally Controlled Tunnel StabilityStructurally Controlled Tunnel StabilityWedge FormationWedge Formation
from Hoek, 2000
Tunneling Sequence for Wedge StabilityTunneling Sequence for Wedge Tunneling Sequence for Wedge StabilityStability
from Hoek, 2000
Kinematic Stability AnalysisDFN ApproachKinematic Stability AnalysisKinematic Stability AnalysisDFN ApproachDFN Approach
3D Discrete Fracture Network Based on Field Measurement
Simulated Slope Surfaces Reflect Effect of Fracture Size
Rock Bridge Failure Reflected by Selective Increasing of Fracture Size
Trace Maps and Wedge IdentificationTrace Maps and Wedge IdentificationTrace Maps and Wedge Identification
DFN Approach: Tunnel Scale ModelingDFN Approach: Tunnel Scale ModelingDFN Approach: Tunnel Scale Modeling
Integrate Hydraulic, Grout, and Geologic Data During Tunnel Advance
Condition Model to Groundwater Monitoring and Grout Take
Update Model to Predict Structural Intersection Events
Task 5 DFN Model - Deterministic FracturesTask 5 DFN Model Task 5 DFN Model -- Deterministic FracturesDeterministic Fractures
Weir Flux Time History Boundary ConditionWeir Flux Time History Boundary Weir Flux Time History Boundary ConditionCondition
Total Flow into Weir
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
03-Mar-91
01-Jun-91
30-Aug-91
28-Nov-91
26-Feb-92
26-May-92
24-Aug-92
22-Nov-92
20-Feb-93
21-May-93
19-Aug-93
17-Nov-93
15-Feb-94
16-May-94
14-Aug-94
12-Nov-94
10-Feb-95
11-May-95
09-Aug-95
07-Nov-95
05-Feb-96
05-May-96
03-Aug-96
01-Nov-96
30-Jan-97
30-Apr-97
Date
Wei
r Fl
ow R
ate
(l/m
in)
Head in Monitoring Section KAS06 MA66Head in Monitoring Section KAS06 Head in Monitoring Section KAS06 MA66MA66
KAS06 MA66
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10.001
-Oct
-90
30-D
ec-9
0
30-M
ar-9
1
28-J
un-9
1
26-S
ep-9
1
25-D
ec-9
1
24-M
ar-9
2
22-J
un-9
2
20-S
ep-9
2
19-D
ec-9
2
19-M
ar-9
3
17-J
un-9
3
15-S
ep-9
3
14-D
ec-9
3
Date
Hea
d (m
)
Measured
H-8
Head in Monitoring Section KAS08 MA81Head in Monitoring Section KAS08 Head in Monitoring Section KAS08 MA81MA81
KAS08 MA81
-30.0
-25.0
-20.0
-15.0
-10.0
-5.0
0.0
5.001
-Oct
-90
30-D
ec-9
0
30-M
ar-9
1
28-J
un-9
1
26-S
ep-9
1
25-D
ec-9
1
24-M
ar-9
2
22-J
un-9
2
20-S
ep-9
2
19-D
ec-9
2
19-M
ar-9
3
17-J
un-9
3
15-S
ep-9
3
14-D
ec-9
3
Date
Hea
d (m
)
Measured
H-8
Head in Monitoring Section KAS07 MA74Head in Monitoring Section KAS07 Head in Monitoring Section KAS07 MA74MA74
KAS07 MA74
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10.0
01-10-90
29-01-91
29-05-91
26-09-91
24-01-92
23-05-92
20-09-92
18-01-93
18-05-93
15-09-93
13-01-94
Date
Hea
d (m
)
Measured
Simulated
Geochemistry in Monitoring Well SA0813BGeochemistry in Monitoring Well Geochemistry in Monitoring Well SA0813BSA0813B
SA0813B
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
01-O
ct-9
0
30-M
ar-9
1
26-S
ep-9
1
24-M
ar-9
2
20-S
ep-9
2
19-M
ar-9
3
15-S
ep-9
3
14-M
ar-9
4
10-S
ep-9
4
09-M
ar-9
5
05-S
ep-9
5
03-M
ar-9
6
30-A
ug-9
6
26-F
eb-9
7
Date
Com
pone
nt P
erce
ntag
e
Sim Cpt 1 Sim Cpt 2 Sim Cpt 3 Sim Cpt 4 Sim Cpt 5 Sim Cpt 6 Sim Cpt 7Data Cpt 1 Data Cpt 2 Data Cpt 3 Data Cpt 4 Data Cpt 5 Data Cpt 6 Data Cpt 7
Geochemistry in Monitoring Well SA2783AGeochemistry in Monitoring Well Geochemistry in Monitoring Well SA2783ASA2783A
SA2783A
-20%
-10%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
01-O
ct-9
0
30-M
ar-9
1
26-S
ep-9
1
24-M
ar-9
2
20-S
ep-9
2
19-M
ar-9
3
15-S
ep-9
3
14-M
ar-9
4
10-S
ep-9
4
09-M
ar-9
5
05-S
ep-9
5
03-M
ar-9
6
30-A
ug-9
6
26-F
eb-9
7
Date
Com
pone
nt P
erce
ntag
e
Brine, Simulated Baltic Sea, Simulated Glacial, Simulated Meteoric, SimulatedBrine, Measured Baltic Sea, Measured Glacial, Measured Meteoric, Measured
Grout Reliability IssuesGrout Uptake to a Dominant FractureGrout Reliability IssuesGrout Reliability IssuesGrout Uptake to a Dominant Fracture
Grout Reliability IssuesSubvertical Fractures Missed by Grouting and Confirmation Test Holes
Grout Reliability IssuesGrout Reliability IssuesSubvertical Fractures Missed by Grouting and Confirmation Test Holes
Grout Reliability IssuesSuccessful Confirmation Tests Signifying Nothing
Grout Reliability IssuesGrout Reliability IssuesSuccessful Confirmation Tests Signifying Nothing
Grout Reliability IssuesPeriodic/Regular Ungrouted FracturesGrout Reliability IssuesGrout Reliability IssuesPeriodic/Regular Ungrouted Fractures
Tunneling Model: Realistic Geology and HydrogeologyTunneling Model: Realistic Geology and Tunneling Model: Realistic Geology and HydrogeologyHydrogeology
Streamline for flow andtransport definedperpendicular to
pressure contoursPressureContours
Source
Sink
a) Continuum Model
b) Pathways Controlled by Fracture Geometry
DFN Tunneling Model: Prediction of Difficult GroundDFN Tunneling Model: DFN Tunneling Model: Prediction of Difficult GroundPrediction of Difficult Ground
DFN Incorporates Flow Barrier and Conductive Structures
Correlate Geology,Grout Take and Hydraulic Response to Upcoming Structures
Predict Structure Intersections
Direct Interaction with Contractor
Tunneling ModelDemonstrate Grout EffectivenessTunneling ModelTunneling ModelDemonstrate Grout EffectivenessDemonstrate Grout Effectiveness
Tunnel Impact Modeling without Grout
Grouting Simulation
Phreatic Surface Impacts at Distance
Tunnel Inflows and Chemistry w/ and w/o Grouting
Monitoring Model: Establish Seasonal/ Diurnal VariationsMonitoring Model: Monitoring Model: Establish Seasonal/ Diurnal VariationsEstablish Seasonal/ Diurnal Variations
Site 910
1880
1890
1900
1910
1920
1930
1940
1950
1960
01-0
4-95
01-0
7-95
01-1
0-95
01-0
1-96
01-0
4-96
01-0
7-96
01-1
0-96
01-0
1-97
01-0
4-97
01-0
7-97
01-1
0-97
01-0
1-98
01-0
4-98
01-0
7-98
01-1
0-98
01-0
1-99
01-0
4-99
01-0
7-99
01-1
0-99
01-0
1-00
01-0
4-00
01-0
7-00
01-1
0-00
01-0
1-01
01-0
4-01
01-0
7-01
01-1
0-01
Date
Elev
atio
n (ft
, MSL
)
Model Natural Variation in Phreatic Surface
Establish Criteria for Identifying Potential Tunnel Effects
Model Phreatic Surface as Tunneling Progresses
Monitoring ModelCorrelation to Tunnel AdvanceMonitoring ModelMonitoring ModelCorrelation to Tunnel AdvanceCorrelation to Tunnel Advance
Simulate Head Reponse(Predictive) at different tunnel inflow rates
Update Model as tunnel advances
Correlate phreatic responses to Tunnel Advance (if any)
KAS07 MA74
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10.0
01-10-90
29-01-91
29-05-91
26-09-91
24-01-92
23-05-92
20-09-92
18-01-93
18-05-93
15-09-93
13-01-94Date
Hea
d (m
)
Measured
Simulated