Direction Territoriale Normandie Center
Direction Territoriale Normandie Center
Durand E.,Direction Territoriale Normandie Center |
Maurin J.,Center Val Of Loire |
Bridoux B.,Center Val Of Loire |
Boulay A.,DDT45 |
Bontemps A.,Direction Territoriale Normandie Center
E3S Web of Conferences | Year: 2016
Along the river Loire, in order to have a homogenous method to do specific risk assessment studies, a new model named CARDigues (for Levee Breach Hazard Calculation) was developed in a partnership with DREAL Centre-Val de Loire (owner of levees), Cerema and Irstea. This model enables to approach the probability of failure on every levee sections and to integrate and cross different "stability" parameters such topography and included structures, geology and material geotechnical characteristics, hydraulic loads... and observations of visual inspections or instrumentation results considered as disorders (seepage, burrowing animals, vegetation, pipes, etc.). This model and integrated tool CARDigues enables to check for each levee section, the probability of appearance and rupture of five breaching scenarios initiated by: overflowing, internal erosion, slope instability, external erosion and uplift. It has been recently updated and has been applied on several levee systems by different contractors. The article presents the CARDigues model principles and its recent developments (version V28.00) with examples on river Loire and how it is currently used for a relevant and global levee system diagnosis and assessment. Levee reinforcement or improvement management is also a perspective of applications for this model CARDigues. © 2016 The Authors, published by EDP Sciences.
Araujo S.,Direction Territoriale Normandie Center |
Araujo S.,CNRS Material Physics Group |
Beaucamp B.,Direction Territoriale Normandie Center |
Delbreilh L.,CNRS Material Physics Group |
And 3 more authors.
Construction and Building Materials | Year: 2017
In this paper, the compactness of a newly-paved road is assessed by means of non-destructive Step Frequency Radar (SFR) as an alternative to cores testing and nuclear gauges usually performed in laboratory or on site. Moreover, our approach allows the estimation of compactness whereas the road contained 38% in weight of recycled component with unknown physical properties. Usually Hot Mix Asphalt (HMA) properties have to be well known to apply electromagnetic mixing models which are required to evaluate the density/compactness from the measured permittivity. Two electromagnetic mixing model families, Power Law (PL) models and Unified Mixing Rules (UMR), are investigated here for 5-phase material, including aggregates, recyclates, binder, filler and air. In order to assess accurately the compactness, three methods are developed. First, without any laboratory experiment, compactness is estimated directly from SFR measurements from a best-fitting approach constrained by manufacturer compactness specification. Second, performing a permittivity measurement of aggregates by means of resonant cylindrical cavities in laboratory, compactness is assessed accurately. Finally, in order to evaluate the second approach according to standard methods, the HMA compactness is obtained by back-calculating the permittivity of recyclates based on reference compactness results (cores and nuclear gamma bench controls) performed in laboratory. Additionally, the thickness of the top layer of the base course is estimated simultaneously with the compactness for both static (SFR measurements at given location) and dynamic modes (SFR system embedded in vehicle). This point helps to best-understanding the deviation observed on the results. In conclusion, this study shows that CRIM (PL family), Rayleigh and Böttcher models (UMR family) are well-adapted to assessed HMA compactness in the microwave band. Moreover, the second approach proves that HMA compactness of newly-paved road can be assessed both in static and dynamic modes with an error compared to the standard measurements weaker than 1%, by means of permittivity measurement in laboratory, without the need of nuclear gauges or destructive techniques. © 2017 Elsevier Ltd.
Fargier R.,Direction Territoriale Normandie Center |
Antoine R.,Direction Territoriale Normandie Center |
Dore L.,Direction Territoriale Normandie Center |
Lopes S.P.,University of Nantes |
Fauchard C.,Direction Territoriale Normandie Center
Geophysics | Year: 2017
The monitoring of underground cavities plays a key role in risk management policies. Mine and underground quarry stakeholders require relevant methodologies and practices to define and assess hazards associated with these structures. To monitor these structures, geophysical methods may offer an interesting compromise among operating cost, invasiveness, and risk assessment reliability. The use of conventional 3D-electric resistivity imaging (ERI) software validated on relatively flat media is not sufficient to efficiently assess complex 3D geometries such as underground mine pillars. We have developed a new approach to evaluate pillar condition by means of a sequential use of two techniques. First, the photogrammetric method yields a detailed 3D model of the pillar geometry from a set of pictures. Second, 3D-ERI is performed based on this suitable geometry. The methodology is tested on a synthetic model to evaluate the effect of various geometry resolutions on the inversion. We also evaluated the combination of the effect of measurement and geometry error. We performed a quasi 3D-ERI survey (three parallel electrode lines) on a real limestone mine pillar to determine the benefits and limitations of the combined procedure. First results revealed the capacity of the photogrammetric methods to obtain a high-precision geometry and its key role during the inversion process. Second results of the real case study revealed that a highly accurate geometry is required to detect accurately conductive anomalies in a complex 3D context. © 2017 Society of Exploration Geophysicists.
Bievre G.,University Grenoble Alpes |
Lacroix P.,University Grenoble Alpes |
Oxarango L.,University Grenoble Alpes |
Goutaland D.,Direction Territoriale Center Est |
And 2 more authors.
Journal of Applied Geophysics | Year: 2017
This paper investigates the combined use of extensive geotechnical, hydrogeological and geophysical techniques to assess a small earth dyke with a permanent hydraulic head, namely a canal embankment. The experimental site was chosen because of known issues regarding internal erosion and piping phenomena. Two leakages were visually located following the emptying of the canal prior to remediation works. The results showed a good agreement between the geophysical imaging techniques (Electrical Resistivity Tomography, P- and SH-waves Tomography) and the geotechnical data to detect the depth to the bedrock and its lateral variations. It appeared that surface waves might not be fully adapted for dyke investigation because of the particular geometry of the studied dyke, non-respectful of the 1D assumption, and which induced depth and velocity discrepancies retrieved from Rayleigh and Love waves inversion. The use of these classical prospecting techniques however did not allow to directly locate the two leakages within the studied earth dyke. The analysis of ambient vibration time series with a modified beam-forming algorithm allowed to localize the most energetic water flow prior to remediation works. It was not possible to detect the leakage after remediation works, suggesting that they efficiently contributed to significantly reduce the water flow. The second leakage was not detected probably because of a non-turbulent water flow, generating few energetic vibrations. © 2017 Elsevier B.V.
Le Kouby A.,University of Marne-la-Vallée |
Chevalier C.,University of Marne-la-Vallée |
Saussaye L.,Direction Territoriale Normandie Center
Scour and Erosion - Proceedings of the 8th International Conference on Scour and Erosion, ICSE 2016 | Year: 2016
The deep Soil-Mixing technique consists in mixing a hydraulic binder into the soil mechanically in order to improve its properties. As far as dikes are concerned, two methods are available. The dry method which is one of these, consists in making a 1 m pre-trenched zone where cement powder is spread and the mixing tool mixes the soil and the cement with water down to a depth of 9 m from the top of the dyke. For the study of erodibility with laboratory tests, a hole erosion test apparatus is used in order to characterize the internal erosion of soils. Samples created in the laboratory as well as cored samples have been tested to get some ranges of soil-mixed responses. © 2016 Taylor & Francis Group, London.
Bordel S.,ERA33 Cerema |
Somat A.,University of Rennes 1 |
Barbeau H.,Erdyn Atlantique |
Anceaux F.,University of Valenciennes and Hainaut‑Cambresis |
And 6 more authors.
Accident Analysis and Prevention | Year: 2014
This article presents the methodology developed within the framework of the research project SARI (Automated Road Surveillance for Driver and Administrator Information). This methodology is based on the logic of action research. The article presents the different stages in the development of technological innovation addressing vehicle control loss when driving on a curve. The results observed in speed reduction illustrate that no matter how optimal an innovation may be technologically speaking, it is only as effective as it is acceptable from a user standpoint. This acceptability can only be obtained if the technology is developed by engineers in liaison with social science specialists. © 2014 Elsevier Ltd.
PubMed | University of Valenciennes and Hainaut‑Cambresis, ERA33 Cerema, Erdyn Atlantique, IFSTTAR and 2 more.
Type: | Journal: Accident; analysis and prevention | Year: 2014
This article presents the methodology developed within the framework of the research project SARI (Automated Road Surveillance for Driver and Administrator Information). This methodology is based on the logic of action research. The article presents the different stages in the development of technological innovation addressing vehicle control loss when driving on a curve. The results observed in speed reduction illustrate that no matter how optimal an innovation may be technologically speaking, it is only as effective as it is acceptable from a user standpoint. This acceptability can only be obtained if the technology is developed by engineers in liaison with social science specialists.
Antoine R.,Direction Territoriale Normandie Center |
Antoine R.,University of Rouen |
Fauchard C.,Direction Territoriale Normandie Center |
Fauchard C.,CNRS Laboratory for the Characterization of Amorphous Polymers |
And 2 more authors.
International Journal of Geophysics | Year: 2015
Ground penetrating radar (GPR) is a nondestructive method allowing the improvement of our knowledge of civil engineering structures. In particular, this method may be a nondestructive efficient tool for dike diagnosis and complete classical geotechnical methods. In this paper, we present GPR observations obtained on an earth embankment (crest and sloped paved revetment) in bad condition and located on the lateral canal of the Loire river (Saint Firmin, 80 km South East of Orléans). These measurements are combined with corings, visual inspection, and permeability logging performed with an updated drilling system, the Perméafor. This survey leads (i) to the detection of decompressed zones associated with leakage areas visible at the foot of the downstream slope and (ii) to the location of potentials voids underneath the paved revetment. This multidisciplinary approach complied with the dike inspection methodology proves its efficiency for the assessment of earth embankments. © 2015 Raphaël Antoine et al.
Rica H.C.,École Supérieure d'Ingénieurs des Travaux de la Construction de Caen |
Saussaye L.,Direction Territoriale Normandie Center |
Saussaye L.,University of Caen Lower Normandy |
Boutouil M.,École Supérieure d'Ingénieurs des Travaux de la Construction de Caen |
And 2 more authors.
Engineering Geology | Year: 2016
Soil stabilizationwith lime and hydraulic binders is a widely used technique to improve the stability and the mechanical properties of soils for use in road construction. However, the presence of substances such as sulphates can induce the swelling, cracking and loss of some mechanical properties defined as disruptive behaviours. This paper analyses the disturbances on the treatment of one silty soil contaminated with sulphates, chlorides, phosphates and nitrates salts, separately then by combinations of two salts. Tests in accelerated curing conditions are used as they are the first realised by the embankments companies, before undertaking further study. The impact of each soluble salt depends on the associated anion and cation. It is not possible to establish a degree of disturbance by cation or anion type. The deleterious effects of sulphates can change if other salts coexist in the soil (i.e., Vs (Volumetric swelling) equal 7% in case of potassiumsulphate contamination,whereas Vs reaches 18 and 23% with a crossed contamination of potassium-sodium sulphates and potassium sulphate-chloride respectively). The influence of complete salts, instead of anions only, should be integrated in technical guides to improve the reliability of the suitability tests they propose. © 2016 Elsevier B.V.