The City of Paris has decided to build a storage and compensation tank near the Gare d’Austerlitz.
As a reminder, the project involves the construction of four main structures:
Soletanche Bachy France has contributed to reducing the project’s carbon impact through numerous actions, both in advance of the project and during the worksite execution phase:
This large structure will have a high retention capacity and be subject to significant uplift pressure. One of the project’s challenges lies in optimising the lengths of the raft-anchoring foundations.
In addition to the mixed anchoring initially planned, made up of 20 barrettes and 236 micropiles, the project was expanded to include a tensile test on a barrette.
The slab foundations were optimised by conducting a load test on a specific barrette, allowing the removal of 236 micropiles and the addition of just 12 additional barrettes using the O-Cells method – a first in France!
86,000m3 of spoil needed to be removed from the site, particularly from the tunnel. The consortium opted for a semi-trailer combined with a barge to remove it. This system saved 960 tonnes of CO2.
Carbon footprint of spoil transportation (tCO2)
Road transport only
River and road transport
After Testimonio II, the electric Hydrofraise® joined the Austerlitz worksite for construction of the tank’s circular diaphragm walls (work which has just been completed).
This move was not a foregone conclusion however.
The teams encountered a major new challenge during the preparatory phase of the work.
Unlike the project in Monaco, which took place in a restricted space where every square meter was put to good use, the massive structures to be built for the Austerlitz project are located in a large worksite where the use of an electric Hydrofraise® needed large-scale electrical coverage.
The worksite teams therefore worked with the equipment department to develop a system with multiple connections around the structure, in order to facilitate use of the Hydrofraise® at all times.
This first use of the electric power pack in France therefore reduces the worksite’s greenhouse gas emissions by around 70%, representing a saving of 786 tonnes of CO2. Measurements carried out on the worksite by an inspection office also reveal a reduction of more than 5dBA in the noise generated by the Hydrofraise® power pack. This benefit was accompanied by a very significant reduction in vibrations.
The diaphragm walls of the Tournaire and Valhubert shafts required approximately 25,000m3 of concrete foundations. The availability of low-carbon concrete on the market enabled the worksite to reduce its CO2 emissions by 1,300 tonnes.
Other more regular actions are carried out by our teams on the worksite. A commitment by everyone: