 |
| Titel |
Medway Tunnel Road Pavement Survey Using Different Frequency GPR Antenna Systems – A Case Study |
| VerfasserIn |
Morteza Amir Alani, Kevin Banks |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114703
|
| Publikation (Nr.) |
 EGU/EGU2015-15509.pdf |
|
|
|
|
|
| Zusammenfassung |
| This presentation reports on an extensive survey carried out on a section (just outside the
westbound end of the tunnel portal) of the Medway Tunnel in North Kent, UK. The
Medway Tunnel provides a dual carriageway road crossing under the River Medway
between Chatham and Strood. It is 725 metres long from portal to portal and consists
of three sections. The appearance of repeated cracking of the road surface in this
particular section of the tunnel suggested either a steady movement of the ground or
possible undermining due to an underground watercourse. Ironically, the design and
construction of the road had been realised to prevent any form of structural movement. It
was deemed necessary to perform a Ground Penetrating Radar (GPR) survey in
order to confirm underground construction details of the road in this section of the
tunnel.
This presentation reports on the detailed survey and the challenges encountered during the
operation, which utilised four different frequency GPR systems including 2GHz, 900MHz,
600MHz and 200MHz antennas. The presentation will also describe how decisions were
made to carry out supplementary surveys based on results obtained on-site (via primary data
processing) and observations made during the survey.
A summary of results will be presented individually for each antenna system
used, as well as comparisons between each antenna system. Results will then be
mapped against the design drawings available for confirmation of construction
configurations.
In conclusion, the presentation will demonstrate that the tunnel road pavement is not
constructed as per the information provided (design drawings). Results will clearly indicate
that there is no second reinforced concrete layer present in this particular section of the road
pavement (contrary to what was originally believed) and will present the actual road
construction in comparison with the design drawings.
The results will confirm that there is no underground watercourse present in this
particular section of the tunnel (at 2-3 m depth). However, it will confirm the presence of an
unknown feature at a depth of 1.2m below road surface.
Acknowledgement
The authors would like to acknowledge the support of the COST Action TU1208 project,
as well as Medway City Council’s immense support in terms of expert workforce and road
survey equipment in materialising this work. |
|
|
|
|
|
|