Papers by Jean-Robert Courivaud
The Dam Safety Interest Group (DSIG) of CEA Technologies, Inc. (CEATI) is an international group ... more The Dam Safety Interest Group (DSIG) of CEA Technologies, Inc. (CEATI) is an international group of dam owners that pursues collaborative research on a wide range of topics. Since 2004 the DSIG has been working to facilitate the development and deployment of a physically-based embankment dam breach model. The group, with assistance from non-CEATI member organizations, has completed a first
This report presents some results of the ERINOH research project, dealing , with internal erosion... more This report presents some results of the ERINOH research project, dealing , with internal erosion in dams and dikes and their foundations. Two databases , have been compiled: one of internal erosion incidents and another of case , histories of failures to be used to validate numerical models. These databases , are tools for improving the safety of dams. The 6 failures recorded were caused , by concentrated leak erosion and by backward erosion. Most internal erosion , incidents occurred in the foundations, where filters are not always effective. , Defective drainage and heavy flows through coarse soils were the causes of 80% , of the malfunctions in the dike on the river Rhône. , The equations published in the literature, expressing the width of the , breach opening and the flow versus the height of the dam, simply do not apply to , dikes, and numerical models of erosion applied to breaching of dikes have to , take into account the erosion of the foundation, which in many cases repre...
Ensuring the safety of hydraulic embankment structures, including embankment dams, levees and dyk... more Ensuring the safety of hydraulic embankment structures, including embankment dams, levees and dykes, is a major concern all over the world. Still today, about one to two large dams fail every year in the world and hundreds, probably thousands, of dykes and levees fail every year in the world. Embankment hydraulic structures can be subject to three potential failure modes: instability, internal erosion and external erosion. The physical parameters driving instability are the pore pressures inside the embankment and its foundation. This failure mode covers both general slope sliding and instabilities due to seismic loadings. Statistics show that 6% of the failure of large embankment dams are due to that process. Internal erosion can be initiated in the embankment and/or in its foundation by four several types of processes: crack erosion, contact erosion, regressive erosion and suffusion. Crack erosion and regressive erosion can lead to one of the most sudden and dangerous failure mode...
Evaluating the erodibility of a soil, both in terms of erosion threshold (initiation) and erosion... more Evaluating the erodibility of a soil, both in terms of erosion threshold (initiation) and erosion rate (progression), is critical for the evaluation of the safety of water retaining structures. Indeed different soils can erode at different rates. However, the relationship between the erosion parameters and the geotechnical and chemical properties of soils remains largely unknown. The jet erosion test appears to be an efficient and simple means for quantifying the two erosion parameters involved. The first parameter is the critical stress while the second parameter is the erosion coefficient. A simplified model of this test has been drawn up by G. Hanson et al to interprete the experimental curves. Few attempts have been made so far to modelthe whole process, however. The aim of this study is to simulate the impinging jet and to take into account the erosion of the soil by means of computational fluid dynamics (CFD) numerical modelling. The key point was the time dependence of the pr...
The Dam Safety Interest Group (DSIG) of CEA Technologies, Inc. (CEATI) is an international group ... more The Dam Safety Interest Group (DSIG) of CEA Technologies, Inc. (CEATI) is an international group of dam owners that pursues collaborative research on a wide range of topics. Since 2004 the DSIG has been working to facilitate the development and deployment of a physically-based embankment dam breach model. The group, with assistance from non-CEATI member organizations, has completed a first phase of work which identified promising numerical models presently under development and compiled real-world case study data and large-scale laboratory test data for future use in model validation. In the second phase of the project, the group will evaluate candidate modeling technologies using the assembled data sets and then integrate selected technologies into the HEC-RAS dynamic routing model suite. Parallel work is also underway to evaluate methods for quantifying the erodibility of embankment materials, a key input for a new and improved model. At this time, the models under consideration are primarily capable of analyzing embankments with simple geometries experiencing overtopping flow. In a future third phase, the group plans to pursue capabilities for more complex and varied embankment configurations and for breaches initiated by internal erosion and piping.
Advances in Civil Engineering, 2010
Although optical fiber sensors have been developed for 30 years, there is a gap between lab exper... more Although optical fiber sensors have been developed for 30 years, there is a gap between lab experiments and field applications. This article focuses on specific methods developed to evaluate the whole sensing chain, with an emphasis on (i) commerciallyavailable optoelectronic instruments and (ii) sensing cable. A number of additional considerations for a successful pairing of these two must be taken into account for successful field applications. These considerations are further developed within this article and illustrated with practical applications of water leakage detection in dikes and concrete structures monitoring, making use of distributed temperature and strain sensing based on Rayleigh, Raman, and Brillouin scattering in optical fibers. They include an adequate choice of working wavelengths, dedicated localization processes, choices of connector type, and further include a useful selection of traditional reference sensors to be installed nearby the optical fiber sensors, as well as temperature compensation in case of strain sensing.
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Papers by Jean-Robert Courivaud