gyroscopic verifications in tunnel surveying aleks kubilius, mike vernikmonteith & sutherland...

Gyroscopic Verifications in Tunnel

Surveying

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

MONTEITH & SUTHERLAND LTD.

For over 50 years Monteith & Sutherland Ltd. have been providing geospatial solutions. We are reputable and well recognised experts in high precision engineering surveys, tunnel surveying, settlement monitoring, and complex geodetic horizontal and vertical control networks.

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

WHO WE ARESpecialised employees from all over the world

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

GEOSPATIAL SOLUTIONS

• Engineering Geomatics• High Definition Scanning• Control surveys

• Topographic surveys• Hydrographic surveys• GIS

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

DELIVERING RESULTS

• Health & Safety• Passionate team work• Quality Assurance• Foolproof project

deliverables• Design, field, finish

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

GEOMATIC PROJECT COORDINATION

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

Primary control

Secondary control

Tertiary control

PRIMARY CONTROL NETWORK

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Verify coordinate system and datum• Establish relationship between datum and project• Static GPS observations• Maintain long-term fixed coordinates

SECONDARY CONTROL NETWORK

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Establish relationship to Primary Network• Maintain absolute Primary Network accuracy• Triangulate precise and accurate relative Secondary Network• Maintain coordinates for extended periods of time

TERTIARY CONTROL NETWORK

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Connect to Secondary Network• Rapid Total Station positioning• Conduct various engineering works• Short-term longevity

TUNNEL SURVEY INSTRUMENTATION

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Global Positioning System (GPS): rapid-static absolute position• Total Station (TPS): high precision coordinate transfer – angular and

distance• Digital level: high precision elevation transfer• Gyromat: true geodetic north orientation

TUNNEL SURVEY NETWORKS

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Coordinates are established and connected at ground level, sub-surface traversing connects terminal points

• Coordinate transfer occurs at either open or vertical shafts

• Several angular and distance measurements between instrument stations and foresight stations complete the transfer

GYROMAT TUNNEL AUDIT

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

1. Reconnaissance2. Surface baseline campaign3. Tunnel campaigns4. Results5. Alignment

GYROMAT CALIBRATION

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

GYROMAT APPLICATION

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

Establish gyro-surveyed coordinates in relation to an existing network. The collection of data will be achieved with a combination of conventional total station and gyro-survey equipment. The task results will ultimately provide quality assurance and potential adjustments to the existing network and tunnelling works.

Gyroscopic Verifications in Tunnel

Surveying

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

WHAT COULD POSSIBLY GO WRONG?

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

SURVEYING IN TUNNELS

PREDICTABLE ERROR DISTRIBUTION: UNNOTICEABLE TO SIGNIFICANT

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

00°00’15” @ 20m = 0.001m ONLY

DIA 20m

SHAFT

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

WITH ONLY ONE MINOR GEOMETRICAL DEVIATION

INDUCED IN UNREALISTICALLY IDEAL CONDITIONS.

00°00’15” @ 1400m = 0.100m!00°00’15” @ 1900m ≈ 0.150m!

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

REAL WORLD SHAFT AND TUNNEL CONDITIONS:

SIGNIFICANT AND UNPREDICTABLE TEMPERATURE

AND HUMIDITY AMPLITUDES

ALONG ACROSS

AND

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

REAL WORLD IR BEAM BEHAVIOUR:

- Dynamic heavily layered air- Varying Humidity- Dust

SCATTERINGAND

REFRACTIONUNPREDICTABLE

BEAM TRAVEL BACK?

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

Recent case study from the local transit project:

00°00’15”

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

10

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

OUT OF

TOLERANCE!≈80%

HOW IT WOULD LOOK WITHOUT GYRO CORRECTION:

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

Gyro-Grid Azimuth for:5 - 6Meas. Station Target Easting Station Northing Station Easting Target Northing Target Merid. Conv. Raw Gyro Azimuth

(m) (m) (m) (m) (gon) (gon) 1 5 6 309135.865 4839412.062 309181.251 4839429.595 -0.04129 76.57562 76.57633 76.57684 76.57645 76.57706 76.57847 76.5762 76.5765

Average Raw Gyro Azimuth Meridian Conv. Average Raw GA + MC Gyro Grid Az (Gon) Gyro Grid Az (D°M'S")

76.5765 -0.04129 76.5353 76.5285 68°52'32''

Δ Gyro Grid Az - Pre-Gyro

Grid AzGon -0.0029

D°M'S" 359°59'51''

Inverse 00°00'09''

Gyro-Grid Azimuth for:7 - 8Meas. Station Target Easting Station Northing Station Easting Target Northing Target Merid. Conv. Raw Gyro Azimuth

(m) (m) (m) (m) (gon) (gon) 1 7 8 309041.272 4839384.358 309089.015 4839402.148 -0.04039 77.34062 77.33683 77.33694 77.33645 77.33956 77.33857 77.3377 77.3375

Average Raw Gyro Azimuth Meridian Conv. Average Raw GA + MC Gyro Grid Az (Gon) Gyro Grid Az (D°M'S")

77.3375 -0.04039 77.2971 77.2904 69°33'41''

Δ Gyro Grid Az - Pre-Gyro

Grid AzGon -0.0023

D°M'S" 359°59'52''Inverse 00°00'08''

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.

• Drilling contractor• Interference with utilities• Interference with traffic• Considerable interference with mining production• Strict plumb requirements• Damage to tunnel structure• Post-survey sealing / backfill costs• Higher potential for compromising precision and

accuracy

WHY NOT AN ALIGNMENT HOLE INSTEAD?

Gyroscopic Verifications in Tunnel

Surveying

ALEKS KUBILIUS, MIKE VERNIK MONTEITH & SUTHERLAND LTD.