1 Introduction
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To describe the geological and hydrogeological characteristics and the grouting procedures for the Løren tunnel.
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To describe the grouting results: in general, in relation to the rock depression and in relation to the grout consumptions.
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To describe the relationships between DPI water and fracturing factors and grout volumes
2 Ground Conditions and Grouting Procedure for the Løren Tunnel
2.1 Ground Conditions
2.1.1 Soil and Rock Overburden
2.1.2 Groundwater
2.1.3 Bedrock Geology
From | To | Geology |
---|---|---|
B1560 | B1445 | Shale |
B1445 | B1425 | Calcareous shale |
B1325 | B1420 | Syenite |
B1420 | B1395 | Nodular limestone |
B1395 | B1380 | Black shale |
B1380 | B1355 | Syenite |
B1355 | B1340 | Nodular limestone |
B1340 | B1325 | Shale, diabase |
B1325 | B1275 | Alternating nodular limestone and black shale, diabase and syenite |
B1275 | B1175 | Sandstone, diabase and syenite |
B1175 | B1145 | Rhomb-porphyry |
B1145 | B1120 | Nodular limestone |
B1120 | B1070 | Shale |
B1070 | B1040 | Nodular limestone |
B1040 | B980 | Shale, with a small fault and syenite at B1040 |
B980 | B885 | Shale, with layers of bentonite rock |
B885 | B810 | Shale |
B810 | B640 | Calcareous shale with syenite in the tunnel roof |
2.1.4 Weakness Zones and Fractures
2.2 Water Ingress Restrictions
From | To | Leakage for both tubes combined (l/min/100 m) |
---|---|---|
640 | 800 | <10 |
800 | 1350 | <7 |
1350 | 1500 | <10 |
1500 | 1560 | <7 |
Pore pressure reduction (m) | Settlement (cm) | Water ingress for both tubes combined (l/min/100 m) |
---|---|---|
1 | 3 | 3 |
3 | 8 | 7 |
5 | 12 | 10 |
10 | 20 | 20 |
2.3 Grouting
2.3.1 Grout Rig
2.3.2 Grout Curtains1
2.3.3 Grouting Procedure
From | To | Cement type |
---|---|---|
B1550 | B1301 | Rapid cement |
B1294 | B1165 | Micro-cement |
B1159 | B1022 | Rapid cement, used some micro-cement in extra curtain at B1022 |
B1011 | B0936 | Micro-cement |
B924 | B762 | Rapid cement |
B757 | B667 | Micro-cement |
B745 | Single section with rapid cement | |
B1186 | Single section with rapid cement |
Date | Profile number | Hole length (m) | End pressure (bottom/top) (bar) | Description of the grouting procedure for a hole in the curtain |
---|---|---|---|---|
2009.06.23 | B1550–B1535 | 23 | 45 | Rapid cement 340 l w/c 1.0 |
345 l w/c 0.8 | ||||
330 l w/c 0.7 | ||||
600 l w/c 0.5 | ||||
At volumes <100 l, hold pressure at 80 bar for 5 min | ||||
At volumes >1,500 l, the end pressure is 30 bar | ||||
2009.08.07 | B1525 | 15 | 80 | Same as above |
2009.08.07 | B1520–B1452 | 23 | 80 | Same as above |
2009.09.17 | B1440–B1385 | 23 | 80 | Rapid cement |
340 l w/c 1.0 | ||||
330 l w/c 0.7 | ||||
1,200 l w/c 0.5 | ||||
At volumes >1,870 l, controlled curing to stop grouting | ||||
At volumes <100 l, hold pressure at 80 bar for 5 min | ||||
At volumes >1,500 l, the end pressure is 30 bar | ||||
2009.10.22 | B1379–B1346 | 18 | 80 | Same as above |
2009.11.15 | B1333–B1301 | 18 | 80 | Rapid cement |
340 l w/c 1.0 | ||||
330 l w/c 0.7 | ||||
1,200 l w/c 0.5 | ||||
At volumes >1,870 l, controlled curing to stop grouting | ||||
2009.12.08 | B1294–B1274 | 19 | 80/60 | Micro-cement |
340 l w/c 1.0 | ||||
340 l w/c 0.8 | ||||
800 l w/c 0.5 | ||||
At volumes >1,500 l, controlled curing if pressure <30 bar | ||||
2010.01.18 | B1265 | 19 | 60/40 | Micro-cement |
1,000 l w/c 0.8 | ||||
Controlled curing (2 %) at 800 l/hole | ||||
Controlled curing (5 %) at 1,000 l to stop grouting | ||||
Max. 9 m between grouting curtains | ||||
2010.02.02 | B1258–B1239 | 15 | Same as above | |
Max. 6 m between grouting curtains | ||||
2010.02.22 | B1230–B1178 | 15 | 60/40 | Same as above |
Max. 8 m between grouting curtains | ||||
2010.04.08 | B1174–B1165 | 15 | 60/40 | Same as above |
Max. 4 m between grouting curtains | ||||
2010.04.23 | B1161–B1154 | 15 | 80/80 | Rapid cement |
340 l w/c 1.0 | ||||
330 l w/c 0.7 | ||||
530 l w/c 0.5 | ||||
300 l w/c 0.5 with controlled curing | ||||
At volumes <100 l, hold pressure at 80 bar for 5 min | ||||
At volumes >1,500 l, the end pressure is 30 bar | ||||
Max. 9 m between grout curtains | ||||
2010.05.04 | B1144–B1085 | 21 | 80/80 | Rapid cement |
340 l w/c 1.0 | ||||
330 l w/c 0.7 | ||||
230 l w/c 0.5 | ||||
200 l w/c 0.5, controlled curing if pressure is <30 bar | ||||
At volumes <100 l, hold pressure at 80 bar for 5 min | ||||
Max. 10 m between grouting fans | ||||
2010.05.20 | B1074–B1122 | 23 | 80/80 | Same as above |
Max. 12 m between grout curtains | ||||
2010.08.11 | B1011–B935 | 23 | 60/40 | Micro-cement |
800 l w/c 0.8 | ||||
200 l w/c 0.8, controlled curing 2 % | ||||
At volumes >1,000 l, controlled curing 5 % | ||||
Max. 12 m between grouting curtains | ||||
2010.09.21 | B924a–B901 | 23 | 60/40 | Rapid cement |
700 l w/c 0.7 | ||||
500 l w/c 0.5 | ||||
At volumes >1,200, grouting is ended | ||||
Max. 12 m between grouting curtains | ||||
2010.10.06 | B892–B762 | 23 | 60/60 | Rapid cement |
300 l w/c 1.0 | ||||
300 l w/c 0.7 | ||||
400 l w/c 0.5 | ||||
After 900 l and pressure <30 bar, a break in grouting is taken | ||||
Max. 12 m between grouting curtains | ||||
2010.12.03 | B757b–B735 | 23 | 60/60 | Micro-cement |
300 l w/c 0.8 | ||||
300 l w/c 0.5 | ||||
150 l w/c 0.5, controlled curing 3 % | ||||
150 l w/c 0.5, controlled curing 6–8 % | ||||
Max. 12 m between grouting curtainsc
| ||||
2011.01.03 | B723–B767 | 23 | 60/40 | Same as above |
3 MWD and DPI
3.1 Background and Basic Principles
HD (mm)a
| PR (dm/min)b
| HP (bar)c
| FP (bar)d
| DP (bar)e
| RS (r/min)f
| RP (bar)g
| WF (l/min)h
| WP (bar)i
| Time |
---|---|---|---|---|---|---|---|---|---|
32 | 0 | 69.76 | 19.69 | 39.65 | 216.86 | 42.47 | 76.09 | 21.4 | 8:18:49 |
59 | 31.83 | 101.44 | 17.12 | 40.08 | 217.77 | 38.61 | 76.84 | 20.97 | 8:18:49 |
84 | 30.28 | 111.71 | 17.12 | 40.08 | 218.68 | 39.47 | 75.72 | 20.97 | 8:18:50 |
108 | 28.37 | 116.42 | 19.26 | 40.51 | 219.60 | 42.04 | 75.72 | 21.83 | 8:18:50 |
131 | 26.75 | 123.26 | 20.97 | 40.51 | 214.11 | 53.20 | 76.46 | 20.97 | 8:18:51 |
152 | 24.88 | 124.98 | 24.82 | 40.51 | 198.56 | 51.48 | 76.46 | 22.26 | 8:18:52 |
… | … | … | … | … | … | … | … | … | … |
3.2 Data Collection
3.2.1 Water Ingress Measurement
3.2.2 Leakage Mapping and Comparison with the DPI Water Factor
3.3 Processing of DPI and Grouting Data
3.3.1 Interpreted Drill Data
3.3.2 Grouting Data
3.3.3 Hole Number Matching
3.3.4 Content of the Dataset
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Section number
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Hole number
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Hole length
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Hole number from drill data
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Hole number from grouting data
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Rapid cement weight
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Micro-cement weight
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Micro-cement with controlled curing weight
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Grout volume
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W: water factor for a hole
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F: fracturing factor for a hole
4 Results From the Tunnelling
4.1 Grouting
4.1.1 Water Ingress
From | To | l/m | l/m/100 m |
---|---|---|---|
A1545 | A1355 | 6.0a
| 3.2a
|
A1300 | A1220 | 2.7 | 3.4 |
A1220 | A1050 | 8.0 | 4.7 |
A1050 | A749 | 4.0 | 1.3 |
B1562 | B1385 | 12.0b
| 6.8b
|
B1303 | B1232 | 3.0 | 4.2 |
B1232 | B1060 | 5 | 2.9 |
B1060 | B723 | 7.6c
| 2.3c
|
4.1.2 Passing the Rock Depression, Profile nos. 1300–1150
4.1.3 Grout Consumption
4.2 Drill Parameter Interpretation
4.2.1 Water Leakage
4.2.2 Grouting Volumes and the DPI Factors Water and Fracture
5 Discussion and Conclusions
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Structural geology
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Rock properties
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Rock cover
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Rock stress
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Surrounding terrain/topography
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Type of grout and w/c
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End pressure
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Groundwater level
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The order in which the holes are drilled
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The order in which the holes are grouted