COASTS, MARINE STRUCTURES AND BREAKWATERS conference, from 5 to 7 September 2017 in Liverpool, United-Kingdom.
The upcoming Coasts, Marine Structures and Breakwaters conference, which will take place from 5 to 7 September 2017 in Liverpool, is a major event for the players in the maritime structure engineering sector.
In keeping with the legacy of Sogreah, CLI will be participating in this conference with the stand No. 22 showcasing the company’s four emblematic armour units: ACCROPODE™, ACCROPODE™ II, CORE-LOC™ and ECOPODE™. Recent improvements in the technology based on these four artificial concrete armour units will be introduced. Our technical team will be on hand to discuss the details that set our products apart from other technologies, as well as the on-going developments that we will be proposing to you very soon.
A proven technology, simple to implement
The ACCROPODE™ II single-layer technology was developed with a simple principle in mind: the armour unit placement process must be natural, easy and quick in order to allow interlocking through gravity. This was already the motto we had set ourselves originally for the ACCROPODE™ unit with a diamond-shaped mesh, which remains the basic placement grid to this day. This very simple principle could be contested, considering the complex shapes of these armour units and the placement conditions imposed by natural site conditions. Yet in spite of all this, tens of thousands of units are placed every year, an increasing proportion of which are ACCROPODE™ II units, and contractors are delivering structures (more than 300 to date) providing protection from ocean waves all over the world. The technical assistance provided by our experts is a key component in the efficiency of the technologies we propose, and we are committed to a process of improving the services we provide to our clients.
The Key parameter: placement density of the armour units
Of course, the financial risks involved in projects are an issue that cannot be overlooked. During the development of the ACCROPODE™ II unit, CLI decided not publish concrete consumption values that would not correspond strictly to reality. The key parameter in this field is placement density, i.e. the number of units placed on a given surface area. This value is a compromise between ease of placement, the risk of uncontrolled unit movements once the facing has been commissioned, and the need to obtain interlocking that guarantees facing stability.
Each project completed gives us additional information that helps us fine-tune our technologies and the methods and resources we deploy to build our armour solutions. The experience we acquired initially thanks to the first-generation ACCROPODE™, ECOPODE™ and CORE-LOC™ technologies defined fundamentals that remain valid to this day.
Questions exist about the placement density that should be adopted for the single-layer armour units. But the feedback we have received to date is consistent and reinforces our position on this fundamental aspect: the average actual placement density observed on-site is the same as, or even slightly lower than, the theoretical placement density recommended by CLI, the standard deviations remaining perfectly compliant.
Companies that have used our ACCROPODE™ II technology confirm that this result is obtained without having to make any particular efforts during the placement process: the learning curve is fast. The economic results are satisfactory and come as no surprise. This theoretical placement density had been determined based on stability tests carried out in laboratories at Artelia Eau & Environnement and H.R. Wallingford, and it corresponds to an amply satisfactory level of stability. We are always available to answer any questions on this topic.
Production at a faster pace
It is a well-known fact that the construction phase of most projects rarely starts on the scheduled date: the construction contractors then come under pressure to make up for lost time in order to meet commissioning deadlines. The consequence for us is an increasing number of requests to manage risks related to construction and the weather, amongst other factors. The shape of the ACCROPODE™ II unit allows for a natural placement process, eliminating many of the issues encountered with other single-layer units. Placement equipment and the performance levels of lifting equipment, such as the very large hydraulic shovels that have recently emerged, have also contributed to accelerating the process. These improved performance levels must allow seamless implementation of works programmes. This is a very interesting topic upon which we have received a great deal of feedback that we will gladly share.
The Shape of the unit, a key factor
We have learnt from experience on site that the shape of the unit - not just the general shape but also each detail – can be a favourable (or, on the contrary, an unfavourable) factor upon the ease of placement of the armour units. A comparison with armour units of different shapes and the studies performed in collaboration with Imperial College London have lifted the veil on a number of hitherto misconceived phenomena. Recent feedback has confirmed the consistency between theory and reality during the construction phases. This aspect will be further developed with you.
Projects requiring new and innovative methods!
More recently, we were contacted by Contractors to undo a number of habits that had been acquired over the past 30 years. This is a stimulating talking point and several projects have been carried out using innovative methods. We take great satisfaction in seeing that the technologies we propose can be adapted so easily to newly imposed conditions. My recommendation to the profession would therefore be not to restrict ourselves to existing practices but to ask ourselves questions about what could be achieved, without any preconceived ideas. We will improve together, just as we have over the past few decades.
Adapted Communications technologies
Lastly, I would like to conclude by saying that increasing amounts of information are circulating and that some of it is not entirely reliable. Our technologies are constantly being adapted; it is our role to disseminate and share our know-how. We will present to you the communication plans that will be implemented in the coming months.
Michel Fons - Managing Director