High Resolution Terrestrial Laser Scanning for Tunnel Deformation Measurements (4497) |
| Timothy Nuttens, Alain De Wulf, Lander Bral, Bart De Wit and Leen Carlier (Belgium) |
Mr. Timothy Nuttens
Ghent University
Department of Geography
3D Data Acquisition Cluster
Krijgslaan 281 (Building S8)
Gent
9000
Belgium
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| Corresponding author Mr. Timothy Nuttens (email: Timothy.Nuttens[at]UGent.be, tel.: + 32 92644656) |
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| [ abstract ] [ paper ] [ handouts ] |
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Published on the web 2010-01-14
Received 2009-11-19 / Accepted 2010-01-14 |
| This paper is one of selection of papers published for the FIG Congress 2010 in Sydney, Australia and has undergone the FIG Peer Review Process. |
FIG Congress 2010
ISBN 978-87-90907-87-7 ISSN 2308-3441
http://www.fig.net/resources/proceedings/fig_proceedings/fig2010/index.htm
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Abstract |
| Timothy NUTTENS, Alain DE WULF, Lander BRAL, Bart DE WIT, Leen CARLIER, Marijke DE RYCK, Denis CONSTALES, Hans DE BACKER, Belgium
By delivering millions of very accurate 3D points, laser scanning is an alternative for classical topographical measurements with a total station or digital photogrammetry for measurements in difficult field conditions. This makes terrestrial high resolution laser scanning a technique that is increasingly being used for geodetic deformation measurements of civil technical constructions, i.c. newly built tunnels. This paper deals with the error values during processing of a measured tunnel section and the final determination of the deformations of this tunnel section based on 3D laser scan point clouds.
The subject of this research is the still ongoing construction of two railway tunnels under Brussels Airport (Zaventem, Belgium). There are two times six tunnel sections that have to be closely monitored. These tunnel sections have to be scanned immediately after placement of the tunnel section, once a week during the first month after placement and once a month from then on until stabilization of the construction. The concrete surface of the walls is scanned with an average lateral resolution of 5 mm. During the research until now, a workflow to determine the deformations of the tunnel sections is developed for processing the data with one laser scan software package (Trimble Realworks), followed by further analysis with a CAD software. The comparison between the successive measurements is based on the determination of the section radius every 0.1 grad. The differences that are determined between the different points show a stabilization of the construction after the second control measurement. The comparison of the second control measurement with the previous control measurement shows a systematic and random error of less than 1 mm. Different types of laser measurement instruments are used (pulse-based and phase-based laser scanner, robotic total station with scan function) and of each type the experimental standard deviation on the measurements is determined.
Further improvement and extension of the workflow, research on the general trends that occur in the deformations of the different section of the tunnel and research on the correlation between the measured tunnel deformations and simultaneous measured tension measurements is planned in the near future. |
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| Keywords: Laser scanning; Engineering survey; Tunnel surveying; Deformation measurement; terrestrial laser scanning; tunnels; deformation measurements |
