The CACOH, an internationally reputed laboratory, is the result of 80 years’ experience in hydroelectricity and river developments. It plays a major role in CNR Engineering’s capacity to carry out its missions for external clients.
Since the outset, CNR has sought to have its own hydraulics laboratory. Set up in 1936, this laboratory carries out all the studies linked to the design of CNR’s structures on the Rhone. Through time, the missions of the Hydraulic Structure Behavioural Analysis Centre (CACOH) have encompassed analysing the aging of these structures, in order to guarantee safe operations on the river.
The CACOH now focuses on controlling hydraulic risks and optimising the operation of the structures. At the leading edge of technology, it contributes to ensuring that CNR is capable of guaranteeing the highest level of safety. The CACOH is also involved in different research, innovation and development actions that contribute towards gaining recognition for its expertise in France and abroad. 20 of the 45 people working at the CACOH are engineers and they are devoted to creating synergy between six specific fields:
Specialised in building small scale physical models, vital tools for studying hydraulic phenomena, the CACOH can count on some of the world’s leading experts in this field. Its teams currently focus on complex problems by associating physical modelling and numerical modelling in total synergy. 50% of CACOH’s activities are carried out for CNR in the framework of its operations and, in the framework of missions for CNR Engineering, 50% are carried out for projects on behalf of external clients.
Monitoring the materials of hydraulic and engineering structures
CNR monitors its structures to guarantee their safety and evaluate their performances by analysing the complex phenomena that occur in them. CACOH’s engineers and technicians carry out analyses based on measurements and monitoring to identify changes occurring to the structures, determine their actual condition and detect weak precursor signals of possible instabilities. The materials engineering performed at CACOH completes these analyses by studying the pathologies and the performance of the materials composing the structures. Its teams perform a large number of tests according to the national and international standards in force to control quality.
The Panama Locks: a model of design
In the framework of CNR Engineering, the hydraulics laboratory participates in an exceptional project commissioned by the Panama Canal Authority to design its new locks. A 1/30 scale physical model with extraordinary characteristics was built by the CACOH. It was 60 m long, 20 m wide, and included 3,000 Plexiglas elements and more than 100 sensors. The National Engineering Grand Prix was awarded for these works in 2011, thereby strengthening CNR’s position as leader in lock design.
The data from CNR’s 200 hydrometric stations is analysed to predict and characterise the evolution of the flow rates of the Rhone. They allow CNR to programme its hydroelectricity production and optimise its placement on the market, while conforming to strict operating procedures, especially regarding the transit of floods. CACOH’s hydrometry department also performs field measurements aimed at optimising water resources and the design of CNR’s hydraulic projects.
This activity allows CNR to fulfil its obligation to monitor and maintain the bed of the Rhone and its structures in exemplary fashion. CNR’s teams measure and analyse the movements of the river bed caused by inflows of sediment from the tributaries of the Rhone and the dynamics specific to it. The main objectives are to ensure regulatory navigation conditions and control the passage of floods. They are also conducted for specific monitoring of the submerged parts of the structures
Measurement reference support
Measurement reference support is an activity pursued to aid the operational divisions. It ensures the metrological consistency of the measurements linked to structure monitoring. It identifies good practices and provides the framework for their deployment. Lastly, it provides technical expertise to measurement tasks.
Research, innovation and development
All CACOH’s teams are involved in RID actions applied for CNR’s needs. The goal is to optimise the performance of CNR’s industrial facilities, economically, and for the safety and longevity of the structures. In the framework of the RID projects performed in partnership with public and private organisations, CACOH carries out studies to better understand certain complex phenomena inherent to the operation of hydroelectric development schemes. Thus it participates in three major objectives:
- Understanding and stabilising the internal erosion of dikes,
- Managing sediment transport
- Improving the performance of low head turbine units.