Within Grand Paris Express, the integration of tunnels dug in urban environments to create new public transport lines can lead to disorders on existing deep foundations. No recommendations are available to propose static and dynamic reliable numerical calculation.In the case of boring machine and its impact on deep foundations, their response depends on the transverse and lateral distance between pile tip and tunnel head. Moreover, being a three-dimensional process, boring representation in a transversal plane section requires phase construction in order to take into account boring machine advancement and action, making modeling complex. The research project aims at making calculation of deformation due to tunneling reliable. It would propose a procedure relying on some parameters (that can be obtained with reliable tests) and rheological models with already known validity limits. Project partners complementarity will allow to produce operational softwares to enforce this procedure. Six Work Packages have been defined: a)WP1 for project management, b)WP2 for physical modelling and laboratory tests to supply data (parameters for soil/structure and for model structures), c)WP3 for static and dynamic in situ monitoring to get new data, d) WP4 for static numerical modelling where models could evolve with data in relation with research performed in WP2 and considering data from WP3. Indeed, e)WP5 for Numerical and analytical modelling of propagation of induced ground-borne vibrations with new models that would be validated using data from WP2 and WP3, f) WP6 for dissemination and valorization for all partners to propose recommendations for design and building companies.

DISCRET aims at demonstrating the possibility to detect and locate, in real-time, unusual or critical situations in urban areas, based on the analysis of cell phone network data. This detection will be complemented with information extracted from social networks (i.e., Twitter in the context of the project). A prototype of a warning platform for security and emergency operators will be implemented. Several recent research works have shown that major events induce locally significant modifications of the amount and nature of cellular network communications. These anomalies, typically concomitant with the unusual event, may be detected and located based on the network of cell phone antennas. Moreover, the early detection and localization of the events, together with the knowledge of the associated communication activity, allow for a more effective retrieval of information from the social networks. That permits to provide elements of description and context for the detected event and, therefore, to increase the value of the information conveyed by the population via channels that are not explicitly conceived for alerting purposes. DISCRET is a contribution to the second research axis listed in the call for proposals: “broadcasting private warnings”. The originality of the project lies in the joint usage of information generated by the population in a passive way (i.e., through the cell-phone communication activity) and the one produced in an active way through non-specific channels (i.e., online social networks). Social networks are not specifically dedicated to the broadcast of warnings, but they represent popular and major event information and broadcasting media.

The detection and localization of utility networks in an urban setting has over the past few years become a topic of major interest. Standards (i.e. NF S 70-003) require a recognition of utility lines and an accurate location to within 11 cm conducted by certified service companies. According to feedback and evaluations from the scientific and technical teams within the Ministry of Ecological and Solidarity Transition, no solution currently meets the need for mapping underground networks over a large area at an acceptable cost for communities. For such an undertaking, a precise mapping of buried networks through combining physical methods, artificial intelligence (AI) methods and innovative technologies adapted to hybridization, offers an undeniable advantage for optimizing work in terms of both time and costs. This step will also lead to quality gains and help reduce the risks associated with sensitive networks. The PROMETHEUS project seeks to derive such a non-invasive methodological and technological solution, based on 3D radar technology, to structure the urban mapping of underground utility networks. This project is organized in five Work Packages (WPs), including project management (WP0) to coordinate the other WPs. WP1 focuses on the state-of-the-art and specifications for listing and selecting the influential indicators describing utilities and their environment. This selection step will generate output values or classifications for the machine learning techniques developed in subsequent WPs. WP2 is devoted to developing a hybridization approach (Deep Learning & Matrix Pencil Method) for automatic utility detection and classification applied to raw C-scan data acquired from a multi-antenna GPR device. EM signal processing can be introduced for target identification given its sole dependence on geometry and physical properties. This proposed identification step thus entails applying the high-resolution method (Matrix Pencil Method) to frequency responses. Next, a deep learning segmentation will enable automatically detecting and classifying the utilities. In parallel, WP3 focuses on a hybridization approach using GPR processing (3D migration and full-wave form inversion) prior to a deep learning process, implemented for high-yield and automatic investigations, as well as utility location and classification. The final WP (WP4) addresses the constitution of various experimental GPR databases to complement the data modeled in WPs 2 and 3 towards developing methodological approaches. These databases will then be demonstrated on: a controlled test site with several homogeneous soils, a full-scale test site offering water table level control, and several actual sites proposed by the St Quentin Metropolitan Water Authority. The use of a commercial step-frequency 3D radar array system and the design of a laboratory multi-antenna radar prototype will also contribute to database compilation in the effort to devise a global methodology of automatic detection, localization and classification. From an economic standpoint, this operational research proposal is part of the industrial partner’s (Logiroad) technical and commercial roadmap, calling for a solution that provides local authorities with access, at all times, to the full set of information characterizing road resources under their purview. The innovation resulting from this project will greatly improve positioning, thanks to a 3D platform regularly updated with information on road surfaces and structures, ancillary facilities and underground networks, in at least three markets, namely: public works contractors, network specifications, and communities seeking to optimize their road assets. To carry out this project, the five partners (including the St-Quentin Authority as an external partner) will be aided by a research engineer, two PhD students and several Master interns.

Flash-flood forecasting is of crucial importance to mitigate the devastating effects of flash-floods. However, its development has experienced serious setbacks, due to the large number of affected catchments, their small surface areas (1 to 500 km²), their very short response times (limited to a few hours), and the limited knowledge of the assets being exposed. First operational flash flood warning systems have recently been implemented in France and other countries. Nevertheless, the capacities of these systems can still largely be improved (limited anticipation, limited geographic coverage, impacts not represented). In this context, the PICS project proposes a step forward by designing and evaluating integrated forecasting chains capable of anticipating the impacts of flash-floods with a few hours lead-time. This objective will be reached through interactions between varied scientific teams (meteorologists, hydrologists, hydraulic engineers, economists, sociologists) and operational actors (civil security, local authorities, insurance companies, hydropower companies, transport network operators). The integrated short-range forecasting (or nowcasting) chains designed in the project will incorporate the following components: high resolution quantitative precipitation estimates and short range precipitation forecasts (or nowcasts), highly distributed rainfall runoff models designed to simulate river discharges in ungauged conditions, DTM based hydraulic models for the delineation of potentially flooded areas, and finally several impacts models aiming to represent varied socio-economic effects: insurance losses, inundation of critical infrastructures, and also dynamic population exposure and vulnerability. The project will work towards: effectively coupling these various modelling components, evaluating these components in terms of uncertainties and complementarity, and finally assessing the capacity of these nowcasting chains to meet the end-users needs. A particular attention will be put on the consistency across the various components of these chains, in terms of variables used, spatial and temporal resolutions, application scale, and degree of uncertainty. One critical aspect of the project will also be the validation of the results based on case studies. The small ungauged basins context, indeed, is generally synonym of serious data scarcity. For this reason, a particular effort will be devoted in the project to the gathering of appropriate validation datasets (impacts, flood areas, etc.) and to define relevant validation strategies. The project will include case studies related to recent extreme rainfall events observed in the French Mediterranean area: June 2010 floods in the Argens basin, September-October 2014 floods in the Gardons, Vidourle, Hérault and Lez watersheds, and October 2015 floods in several small basins in the Alpes Maritimes territory. This list of case studies will be complemented at the beginning of the project based on the exchanges with the end users. The project will also entail significant efforts to improve and adapt the different components involved in the modelling chains: improvement of distributed hydrological modelling in ungauged conditions, qualification of uncertainties on discharges estimates based on rainfall observations and nowcasts, improvement of 1-D approaches and test of a 2-D model for large scale automatic hydraulic computations, and finally adaptation of the impacts models to take benefit from information on flooded areas provided by the forecasting chain. Considering this work program, the project should enable significant breakthroughs in the field of integrated flash floods impacts nowcasting. The wide representation of potential end users in the project, as members of the end-users group and as project partners, should finally facilitate the transfer of project results towards operational applications.

The technique of reinforcemetn of compressible soils by vertical Rigid Inclusions (RI) is very wide-spread in France and abroad. This technique of composite foundation mixing deep and superficial elements, was developed initially for works of embankment (for infrastructures of transport), but extends in wind turbines and also in industrial buildings today (e.g. logistic platforms), of housing or offices (less than 4-5 floors), schools, hospitals, etc. This technique so fits on all the territory, urbi et orbi, impacts on the choice of the foundations of the constructions and the linear works of transport (roads and railroads), so touching in a little visible, but real way, the citizens in their living environment and for their mobility. The issues addressed here concern the behaviour of the RI-reinforced soil mass: i) Dynamic Loads: Modifying the celerity of surface waves in a medium with periodic inclusions ii) under seismic stress: Inertial and kinematic effects The methodology used is based on the experimental approach of physical modelling on reduced models combined with numerical modelling, all in conjunction with the field. The propagation of surface waves in soil is modified by the presence of heterogeneities (vertical RI), but in what way? In order to answer this question, which concerns railway applications as a priority, reduced "geophysical" models will be carried out, based on the principle of scaling wavelengths, and implemented on the Ifsttar MUSC bench. Numerically, the spectral element method associated with the non-periodic homogenization technique will be implemented. In the case of seismicload, the presence of Ri reinforcement necessarily changes the soil response, but in what way? To study the inertial and kinematic effects of an RI-reinforced soft soil, "geotechnical" small scale models will be tested with the earthquake simulator installed in the Ifsttar centrifuge. Here the frequencies are scaled up. A fine dynamic characterization of centrifuge soils will be carried out in parallel.The so-called macro-element numerical method as well as the so-called transfer curves will be implemented for simplified models, while non-linear 3D finite elements will be used to simulate works under seismic load (such as those studied in centrifuge), before moving to parametric studies of reference structures. The consortium set up to try to increase knowledge on these dynamic issues brings together, around the Ifsttar, a set of partners involved to varying degrees from downstream upstream: i) SNCF-reseau, Ménard, LGP, centrale-Supelec; ii) EDF, Cerema, Terrasol, Ménard, centrale-Supélec, centrale Nantes. Exceptional experimental equipment combined with advanced, sophisticated or simplified numerical modelling will allow to observe, understand and simulate different configurations, to bring new knowledge and make it available to the Construction Engineering.