The presentation will Show you how a gyroscope is working and why it is very useful to use a gyro in tunnelling. Several examples from practice will explain this.

1. Geosystems at HxGN LIVE
Increasing accuracy in high precision survey with
DMT GYROMAT 5000 in combination with LEICA
high-end total station
Volker Schäpe, Volker Schultheiß, Norbert Benecke
Version Date: 04.06.14
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2. DMT GmbH & Co. KG
Company profile
DMT is an international technology service provider in the fields of natural
resources, safety and infrastructure
 DMT was founded in 1990 as a merger of 3 companies founded in 1864
 In the year 2007 DMT joint the TÜV NORD Group
 TÜV Nord Group
 Headquarters in Hannover, Germany
 ~1.056 Mio. € annual turnover in 2013
 ~9.925 Employees in 70 countries
 DMT Group
 Headquarters in Essen, Germany
 ~113 Mio. € annual turnover in 2013
 ~720 employees
 Development department for geo-instruments like GYROMAT 5000
 Service department for surveying tasks

3. 1. Introduction of GYROMAT 5000
2. Application for GYROMAT 5000: high accuracy tunnel survey
3. Examples and case studies
Content
DMT GYROMAT 5000 + LEICA total station
High precision north finding gyroscope

4. 1. Introduction of GYROMAT 5000
2. Application for GYROMAT 5000: high accuracy tunnel survey
3. Examples and case studies
Content
DMT GYROMAT 5000 + LEICA total station
High precision north finding gyroscope

5. DIN 18723 Teil 7 (1990)
(German Standard for Industry
18723 Part 7 from 1990)
A gyroscope (northseeking
gyro) is a pendulous
suspended, electronic driven
gyro, which spin vector is
influenced by gravity and
earth rotation. It will directed
to astronomic north.
Implementation of gyro into
the GYROMAT
Gyro axis
Suspension tape
ω
Introduction of GYROMAT 5000
Principle of a gyroscope

6.  Highest measuring accuracy.. 0,8 mgon
(= 1,2 cm / 1 km)
 Short measuring time ………. 6 – 9 minutes
 Weight without total station …11,5 kg
 Fully automatic measuring sequence
 Preorientation-free measuring method
 Individual theodolite equipping with LEICA
high-end total stations like
TPS1100, TPS1200, TS11, TS15, TS30, TM30
TS50, MS50, TM6100A
and others with accuracy better than 1”
GYROMAT 5000
The most accurate precision-surveying gyroscope in the world

7. 1. Introduction of GYROMAT 5000
2. Application for GYROMAT 5000: high accuracy tunnel survey
3. Examples and case studies
Content
DMT GYROMAT 5000 + LEICA total station
High precision north finding gyroscope

8. Requirements on accuracy of tunnel/roadway position depend on:
 Used tunneling method (e.g. TBM or blasting )
 Use of the tunnel in operation (e.g. high speed railway tunnel / roadway tunnel)
Examples for challenging requirements in accuracy:
 Predefined demounting construction position with 5 cm variance for the TBM
 Required alignment accuracy better than 5 cm at each tunnel position for high
speed railway tunnels
 Required accuracy of 10 cm for cut-through of two underground roadways
High accuracy tunnel survey
Requirements on position measurement in tunnels

9.  Establishment of an efficient Survey System including:
 Surface network, created e.g. by GNSS
 Transfer of surface network into the tunnel via open traverse lines:
 Survey point distances in the tunnel range between 50 m and > 200 m
 Survey points are mostly located at flanks, rarely in the middle of the tunnel
 Deviations and errors propagate with every survey point
 Failures in positioning increase with tunnel length
Deviations are unavoidable!
In particular:
 refraction error
 plumbing error
 error propagation
will lead into lateral deviation
High accuracy tunnel survey
Surveying and directions in tunneling, some considerations

10. Target building
Plumbing Error
α
β1
β2
β3
q
B S
QL
Real direction with plumbing error q
Theoretical direction without plumbing error
Tunnel
length [m]
Lateral deflection
Plumb error: 1 mm
Base length: 10 m
Lateral deflection
Plumb error: 1,5 mm
Base length: 8 m
300 4,2 cm 8,0 cm
1.000 14,1 cm 26,5 cm
10.000 141,4 cm 265,2 cm
β1
β2
β3
Start shaft
High accuracy tunnel survey
Improvement of accuracy by the use of GYROMAT 5000

11. Refraction in a tunnel
Theoretical straight-lined beam
Real tunnel situation: different
layers of temperatures between
the tunnel walls and tunnel
centre lead into refraction
In reality: curved beam
Disregard of refraction leads
into position error QR
Start shaft
Influence of refraction
Theoretical position
QR
A1
A2
A‘2A‘1
Δ Δ
North North
Solution: GYROMAT 5000
delivers the absolute north
direction for every point.
The refraction can be identified
High accuracy tunnel survey
Improvement of accuracy by the use of GYROMAT 5000

12. Gyro supported traverse line in the tunnel
Error propagation
Survey points
Traverse line
Gyro surveyed polygon side
50 – 200 m 500 – 1.000 m
High accuracy tunnel survey
Improvement of accuracy by the use of GYROMAT 5000

13. 1. Introduction of GYROMAT 5000
2. Application for GYROMAT 5000: high accuracy tunnel survey
3. Examples and case studies
Content
DMT GYROMAT 5000 + LEICA total station
High precision north finding gyroscope

14. Water supply tunnel for a 420 MW hydropower plant
Length: 25,8 km, diameter: 7 – 8 m
Driven by two TBM from two sites: intake and outlet
 1 Gyro campaign 1 km before planned cut-through
 Driving status while survey: intake tunnel: 7,5 km
outlet tunnel:17,5 km
 Extreme environmental conditions while survey:
temperature up to 42
О
C; air humidity: 99%
 Result: determination of significant lateral deviation in
both tunnels of up to 2,5 m at calculated cut-through
position
By the way: in consideration of the environmental conditions,
2,5 m lateral deviation is good result for open traverses over
these large distances.
Gilgel Gibe II tunnel in Ethiopia
Case study: water supply tunnel

15. Achieved lateral deviation: < 5 cm
Scenario without correction:
Lateral deviation of > 2,5 m which
corresponds to a third of total tunnel width
Possible consequence of scenario above:
Additional construction efforts to correct the
direction which would had exceeded
multiple the costs and time for gyro
campaign
Result of cut-through after correction of driving direction:
Gilgel Gibe II tunnel in Ethiopia
Case study: water supply tunnel

16. 690 MW hydropower plant,
supplied by two different water
reservoirs in the sub-arctic east
part of Island mountain region.
 Total tunnel length: 72 km
 Driving with 3 TBM from different
starting points
 Allowance of horizontal deviation
at cut-through positions: < 20 cm
 Allowance of deviation from the
target direction for every section
of 100 m: < 15 cm
Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel

17. Challenges for this survey
 Extreme length of single tunnel sections
 Complex geometry with curves and branches leads
to sightings close to the tunnel wall
 Extreme environmental conditions:
- Outside temperatures below -20
О
C
- Inside temperature range from 0О
C to > 40О
C
 High variation of air temperature at tunnel
entrances or ventilation holes
 Air humidity nearly 100 %
 Partly water suddenly flows in with temperatures
up to 51О
C
 Facing considerable, unpredictable and
unavoidable refractions at the traverse
Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel

18. Challenges in
surveying and
alignment
Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel

19. Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel
Challenges in
surveying and
alignment

20. Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel
Challenges in
surveying and
alignment

21. Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel
Challenges in
surveying and
alignment

22.  Faultless operation of GYROMAT 3000 and Leica total
stations TCA1800 and TS30 even with the extreme
weather conditions
 Keeping the required accuracy for all cut-through so that
extensive rework could be avoided.
20 cm was allowed, 5 cm was achieved
Results:
Kárahnjúkar Hydro-Electric Project (Island)
Case study: water supply tunnel

23. Challenges for this survey
 Extreme total length of 57 km
 High demands on accuracy of
max. 10 cm lateral deviation at
every point
 Tunnel work with TBMs from 5
access points. Entrance
Sedrun via 800 m deep shaft
Gotthard Basistunnel (Switzerland)
High speed railway tunnel

24. Quelle: R. Stengele (Swissphoto AG)
Gyro campaign in the driving
Bodio (15,7 km)
 8 Gyro campaigns in
December 2003 and August
2006 with GYROMAT
 624 single azimuth surveys in
total with only 22 outliers;
3,5% which were eliminated
 Determination of 44 reference
azimuths on the surface
network and 38 azimuths in
the underground network with
602 single survey results
Gotthard Basistunnel (Switzerland)
High speed railway tunnel

25. Gotthard Basistunnel (Switzerland)
High speed railway tunnel

26. Gotthard Basistunnel (Switzerland)
High speed railway tunnel

27. Gotthard Basistunnel (Switzerland)
High speed railway tunnel

28. Cut-through Bodio – Faido
on 26.10.2006
Gotthard Basistunnel (Switzerland)
High speed railway tunnel

29. Achieved deviation at cut-through
Bodio – Faido (15,7 km)
Lateral: 9,1 cm
Vertical: 2,3 cm
Cut-through Bodio – Faido on 26.10.2006
Different voices about the result:
Building engineering:
This deviation can be compensated
by optimizing the interior work
Railway engineering:
This deviation can be compensated
by minimal track moving over 300 m
Surveyor:
Considerable result
Insurance:
Risks remain under control
Gotthard Basistunnel (Switzerland)
High speed railway tunnel

30.  Sewer tunnel project of the City of
Portland (Oregon/USA) constructed
by TBM (Herrenknecht)
 Length of 5,5 km with no remarkable
incline or curves, diameter: 5 m
 After the short distance of only 500 m
tunneling two different survey
campaigns
 one by contractor’s surveyor
 one by client’s surveyor
showed lateral differences of more
than 25 cm
Combined Sewer Overflows Tunnel, Portland, USA
West side CSO tunnel project

31.  Problem:
 Tunneling starts from a haulage shaft of
50 m depth and 18 m diameter
 Start-up baseline for survey of only 11 m
length
 Plumbing error of only 2 mm causes
large lateral errors
 Feared result without measurements:
breakthrough disaster
 Measurements:
 Turning the traverse into right orientation
by only two GYROMAT campaigns
 Reached result: successful breakthrough
with an accuracy of a few millimeters
Combined Sewer Overflows Tunnel, Protland, USA
West side CSO tunnel project

32. Guidance system for TBM
Source: VMT GmbH
Tunnel survey System
Efficient survey system
Resume
 Every tunneling project signifies an investment of several million Euro/Dollars
 Tunnel survey take place under difficult environmental conditions
 Small errors have a great impact on the technical and economical success of
the project
 The nightmare of a tunnel driver can be avoided by three steps:
High accuracy tunnel construction
QR
Gyro control survey as insurance
α
β1
β2
β3
q QL
β1
β2
β3

33. DMT GmbH & Co. KG
Exploration & Geosurvey
Contact: Norbert Benecke
Am Technologiepark 1
45307 Essen, Germany
Phone: +49 201 172 2012
Fax: +49 201 172 1791
E-mail: norbert.benecke@dmt.de
Internet: www.dmt.de
Thank you for your attention