Innovative electro-seismic surveying techniques are being used to map out what lies below the surface of the Hikuwai River, bringing the new Hikuwai Bridge a step closer to construction.
A Gisborne-based company is undertaking part of the pre-construction investigations, which will provide design and engineering crews with insights into geological conditions and potential obstructions under the ground.
This quick, non-invasive, non-destructive technique involves using a boat to send gentle seismic waves into the ground. These waves travel through the water and the ground, and when they hit different types of materials, they create electrical signals.
The new Hikuwai No. 1 bridge will replace the temporary Bailey bridge built after Cyclone Gabrielle, with consents expected to be lodged later this year, ahead of construction in 2025.
Transport Rebuild East Coast (TREC) project manager Richard Bayley says this work and other ground investigations to be carried out in the next few weeks will help highlight any issues early so they can be addressed during the design phase.
“The Hikuwai bridge project site is complex, and early investigations like these give our team critical information,” says Mr Bayley.
“By measuring these signals, the team can create a detailed map of what’s below the surface.”
These early investigations also include some drilling to be undertaken by another local contractor and are expected to take up to three weeks to complete.
“The team is working hard towards a construction start early next year and will share more information with the community before Christmas.” Mr. Bayley added.
TREC will continue to work closely with iwi/hapū, landowners, council, and local contractors as they design and deliver the project.
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