Alongside SUBTERRA recently for the successful completion of 3 parallel 360-metre-long HDD crossings under the Gave de Pau river in southern France: a DN250 for Teréga, a DN80 and a DN50 for Arkema. Up until now, the network crossed the river via a dedicated pipe bridge. Placing it underground will ensure optimal security given the river hydrology and the geology of the site.
OPTIMUM engineers worked on both the design and the construction phase of the Gave de Pau project. The drilling profiles for the 3 pipelines were adjusted to almost 30 metres deep to avoid localised gravel formations that had been identified during the geotechnical investigations. With surface gravel over 3 metres deep, steel casings were installed at all three entry points and the exit points were excavated to mitigate against the risk of hole collapse. Drilling logs were monitored remotely throughout the construction phase and trenchless specialists followed key stages onsite, ensuring the combined 1km+ HDD construction ran smoothly.
Congratulations to all the teams involved.
