Teréga continues to reinforce its gas transport network in south-eastern France and OPTIMUM trenchless engineers continue to accompany the project owner at every step.
The latest project, near Montauban (Tarn-et-Garonne), will add some 23km to the network, so crossing under key infrastructure and natural obstacles was both inevitable and critical to success. Three of the HDD (horizontal directional drilling) crossings, design engineered and supervised by OPTIMUM, are now complete :
- Under the high velocity Garonne river : a 444-metre-long HDD housing a DN 200 steel pipe, drilled 14m under the river bed, through deep gravelly surface layers
- Under the A62 motorway : a 242-metre long HDD housing a DN 250 HDPE pipe, drilled 23m below the road
- Under the Azin river : a 217-metre-long HDD housing a DN 80 steel pipe, passing through clayey marl and rock formations, 12m under the riverbed
The importance of the obstacles being passed under in addition to the hard rock formations called for expert engineering design and continuous monitoring during the drilling works by OPTIMUM specialists. Job done, now for the next 3.
