The company Anese has been awarded a contract for the construction of a crossing with the HDD technique for laying gas pipelines in Cornegliano Laudense in the province of Lodi.
This project represented a major challenge for the company, which had to complete the launch of the pipes in a very short time and with a not particularly favorable geological situation.
The customer had the need to realize, 3 gas crossings, in a limited and pre-established time, with parallel cable holder for the fiber optic connection, thus laying two pipelines for each section.
- Length crossing of about 470m
- Length crossing of about 650m
- Length crossing of about 680m
In particular, the geology showed medium-coarse loose soils with gravel content of about 40% compared to the stratum.
They were laid n. 3 steel pipes DN 1050 (42 “) and parallel to them n. 3 DN 200 (8 “) pipes, in a total time of 45 working days, anticipating the initial time schedule by 4 days.
All the crossings were planned to combine the 250 tons maxi rig with the 100 tons rig, in order to proceed the gas and fiber optic conduits in parallel, saving time.
This method of execution was made possible by the fact that both machines have a mirrored rod loading system oriented towards the two external sides of the construction site, so there was no risk of interference that complicated the success of the work.
The distance between the rigs, on the other hand, was calculated according to the rules established by the security plan.
Due to the delicate geological condition, a great attention was paid to the preparation of the drilling muds that had to guarantee that the excavated material was dug off and the waterproofing of the walls of the hole to prevent the entry of ground water that would destabilize the integrity of the hole itself. Considering that for the installation of the 42 “a 1400mm diameter hole is made.
- The Crossings, with the HDD technique, were carried out to complete the gas target line and the corresponding fiber optic cable
- The parallel machine technique made it possible to complete the work in record time