Since 2017, the scale and complexity of the work being carried out on the Testimonio II worksite in Monaco have become legendary.
This project has been an opportunity to implement, accelerate and even develop in synergy with the owner (Marzocco Group and VINCI Immobilier) and VINCI Construction, a large number of actions falling within the scope of objectives defined by the Soletanche Bachy group’s environmental action plan.
Here we review – thematically, from the most spectacular to the most common – all the actions which have contributed to the virtuous transition currently being adopted on our worksites.
Two fresh water springs have an impact on the Testimonio II site.
One, the Testimonio spring, runs through it. The other, the Marie spring, runs alongside it.
Both are collected, to provide a significant share of the Principality’s freshwater supply, or else are discharged into the sea.
It was therefore essential for the works to have as little impact as possible on these water resources, without generating any discharge of mud or grout into the sea.
To preserve these environments, we therefore:
The human and technical resources adopted to monitor methods and technical studies made it possible to optimise adjustments to the project phases while allowing strict monitoring of the observational method, in order to optimise or even eliminate certain unnecessary structures, including:
The work carried out jointly by the materials laboratories of Soletanche Bachy, VINCI Construction and the concrete supplier (EMT) made it possible to define and implement ultra-low carbon concrete reducing CO2 emissions by more than 6,000 tonnes just for the concrete used for the diaphragm walls and barrettes (25,000m3 out of the project’s 100,000m3). To achieve this, fly ash from Gardanne and ground slag from Fos-sur-Mer were used as cement substitutes.
This is the most spectacular innovation implemented on the Testimonio II site. In fact, it is disruptive on two fronts.
1/ The move from the HF07 to the HC05 with grippers® in 2019 significantly reduced fuel consumption by reducing the power of the machine required for excavation.
The gripping impact was very effective as it maintained the level of efficiency with a much more compact machine.
2/ The move from the HC05G to the HC05GE. With further optimised efficiency (greater reliability of the power pack and more linear operation), this new innovation eliminated all CO2 and combustion gas emissions while saving nearly 5,000 litres of fuel per week of work (more than 60,000 litres in the last phase of the works alone).
Worksites in dense urban areas, and in Monaco in particular, can cause a lot of disturbance to local residents. This subject is now a vital issue for current and future work.
Following actions by the authorities to adjust working hours and large-scale but often inefficient deployment of noise-barrier tarps, we decided take much more efficient action by tackling the problem as close as possible to its source:
At Testimonio II, for example, the Soletanche Bachy technical and equipment teams have developed and implemented:
The improvement recorded by Bureau Veritas, appointed by the Monegasque authorities, is 5 to 6 dB (A) compared with competitor’s compact machines, corresponding to a four-fold reduction in noise impact. In fact, since the grippers add more power to our compact Hydrofraise®, it can be compared to the most powerful machines on the market, against which Bureau Veritas records a difference of up to 15 dB (A) in favour of our HC05GE.
These two innovations, particularly the HC05GE, have made a profound impression on the technical services in Monaco since nuisance reduction is an important topic in the Principality.
Much remains to be done, but the Testimonio II site is seen by the construction industry and the authorities in Monaco as exemplary in terms of its performance and the concrete and particularly effective efforts that have been put in place to dramatically reduce the worksite’s impact on the environment and on local residents.
In order to succeed, it is essential to bring together the expectations of the public authorities and the project owner and the collective energies of all the partners in the operation in a relevant manner (VINCI Construction Monaco, GTM Sud et Soletanche SAM).
We are convinced that these actions play a large part in restoring leadership to Soletanche SAM and, more broadly, to the VINCI Group in a very tough competitive environment.