Browsing by Author "Garcia-Sanchez, David"
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Item 3D numerical simulation of slope-flexible system interaction using a mixed FEM-SPH model(2021) Jimenez Fernandez, Jose Carlos; Castanon-Jano, Laura; Gaute Alonso, Alvaro; Blanco-Fernandez, Elena; Gonzalez Fernandez, Juan Carlos; Centeno Gonzalez, Victor; Castro-Fresno, Daniel; Garcia-Sanchez, David; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESFlexible membranes are light structures anchored to the ground that protect infrastructures or dwellings from rock or soil sliding. One alternative to design these structures is by using numerical simulations. However, very few models were found until date and most of them are in 2D and do not include all their components. This paper presents the development of a numerical model combining Finite Element Modelling (FEM) with Smooth Particle Hydrodynamics (SPH) formulation. Both cylindrical and spherical failure of the slope were simulated. One reference geometry of the slope was designed and a total of 21 slip circles were calculated considering different soil parameters, phreatic level position and drainage solutions. Four case studies were extracted from these scenarios and simulated using different dimensions of the components of the system. As a validation model, an experimental test that imitates the soil detachment and its retention by the steel membrane was successfully reproduced.Item Bearing assessment tool for longitudinal bridge performance(2020-11-01) Garcia-Sanchez, David; Fernandez-Navamuel, Ana; Sánchez, Diego Zamora; Alvear, Daniel; Pardo, David; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThis work provides an unsupervised learning approach based on a single-valued performance indicator to monitor the global behavior of critical components in a viaduct, such as bearings. We propose an outlier detection method for longitudinal displacements to assess the behavior of a singular asymmetric prestressed concrete structure with a 120 m high central pier acting as a fixed point. We first show that the available long-term horizontal displacement measurements recorded during the undamaged state exhibit strong correlations at the different locations of the bearings. Thus, we combine measurements from four sensors to design a robust performance indicator that is only weakly affected by temperature variations after the application of principal component analysis. We validate the method and show its efficiency against false positives and negatives using several metrics: accuracy, precision, recall, and F1 score. Due to its unsupervised learning scope, the proposed technique is intended to serve as a real-time supervision tool that complements maintenance inspections. It aims to provide support for the prioritization and postponement of maintenance actions in bridge management.Item Estimating, and setting targets for, the resilience of transport infrastructure(2021-07-30) Adey, Bryan T; Martani, Claudio; Kielhauser, Clemens; Robles, Ignacio Urqulijo; Papathanasiou, Natalia; Burkhalter, Marcel; Beltran-Hernando, Iñaki; Garcia-Sanchez, David; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESTo ensure that transport infrastructure provides acceptable levels of service with respect to extreme events, the resilience of the infrastructure needs to be estimated and targets for it need to be set. In this paper, the methodology proposed in the Foresee EU research project is presented. The methodology allows managers to measure, and set targets for, the resilience of transport systems in all situations. It requires clear definition of the transport system and how the service provided and the resilience are to be measured. The methodology allows consideration of the fact that transport infrastructure managers need to estimate resilience with various degrees of accuracy depending on the specific problem to be addressed, the time frame at disposition and the expertise available. These various levels of accuracy are covered by proposing the use of (a) simulations, (b) indicators whose values are directly related to increases in expected restoration intervention costs and reductions in service, and (c) the percentage of fulfilment of indicators. Once resilience has been estimated, the methodology provides guidance on how to set resilience targets with or without cost-benefit analysis. For demonstration, the explanation of the steps of the guideline is supported by their use for a simple transport system.Item Novel method for an optimised calculation of modal analysis of girder bridge decks(2022-07) Gaute-Alonso, Alvaro; Garcia-Sanchez, David; Ramos-Gutierrez, Óscar Ramón; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESA correct modal analysis of girder bridge decks requires a correct characterisation of the deformation of their cross-section, governed by the longitudinal bending of the girders and the transverse bending of the slab. This paper presents a novel method that allows the modal analysis of girder bridge decks by applying a matrix formulation that reduces the structural problem to one degree of freedom for each girder: the deflection at the centre of the beam span. A parametric study is presented that analyses the structural response of 64 girder bridge decks. The study compares the dynamic structural response obtained by the proposed method with that obtained by traditional grillage calculation methods. The method is experimentally contrasted by a dynamic load test of a full-scale girder bridge. As a result of the analysis, the proposed method reflects adequate convergence with the experimental dynamic structural response. The use of the proposed novel analysis method contributes to the intelligent modelling process for the analysis of the dynamic behaviour of bridges opening the way to easily feed a Digital Twin accelerating the demands of the Decision Support System in real time.Item Novel Method for an Optimised Calculation of the Cross-Sectional Distribution of Live Loads on Girder Bridge Decks(2022-03) Gaute-Alonso, Alvaro; Garcia-Sanchez, David; Uriszar-Aldaca, Iñigo Calderon; Lopez Castillo, Claudio; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESOne of the main goals in the design of girder bridge deck systems is to determine the cross-sectional distribution of live loads across the different girders that make up the cross-section of the deck. Structural grillage models and current bridge design standards based on a Load Distribution Factor (LDF) provide oversized designs, as demonstrated in this paper. This research introduces a novel method that allows the cross-sectional distribution of live loads on girder bridge decks to be calculated by applying a matrix formulation that reduces the structural problem to 2 degrees of freedom for each girder: the deflection and the rotation of the deck-slab at the centre of the girder’s span. Subsequently, a parametric study is presented that analyses the structural response of 64 girder bridge decks to a total of 384 load states. In addition, the authors compare the outputs of the novel method with those obtained using traditional grillage calculation methods. Finally, the method is experimentally validated on two levels: a) a laboratory test that analyses the structural response of a small-scale girder bridge deck to the application of different load states; b) a real full-scale girder bridge load test that analyses the structural response of the bridge over the Barbate River during its static load test. Based on this analysis, the maximum divergence of the proposed method obtained from the experimental structural response is less than 10%. The use of the proposed novel analysis method undoubtedly provides significant savings in material resources and computing time, while contributing to minimizing overall costs.Item Rail expansion devices and maximum dilation length in railway bridges. An experimental study(2021-02-15) Garcia-Sanchez, David; Sañudo, Roberto; Miranda, Marina; Tárrago, Nerea; Lenart, Stanislav; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThe use of rail expansion devices (RED) interrupts the continuity of the welded rail, causing an irregularity with the consequent reduction in comfort, but with the benefit of a significant stress reduction in the rails. Currently the Spanish Railway Administrator uses three types of RED according to their range: 300 (small RED), 600 (medium RED) and 1200 mm (large RED) for all railway structures in the network. Their use has led to the construction of railway bridges and viaducts of maximum free expansion length of just over 1100 m. Development of new high-speed railway lines increasingly demands longer structures. Thus, the maximum allowed free expansion length should be increased. This problem can be faced from two fronts: (1) the improvement of the performance of REDs by developing new designs and (2) the enhanced prediction of the bridges and viaducts real movements caused by retraction, creep and temperature. It is precisely this last approach that has been developed by analysing and reviewing some existing structures. Forty-four bridges and viaducts on the Spanish High- Speed Railway network. Specifically, the railway Lines Madrid-Barcelona, Cordoba-Malaga and Madrid- Valladolid, have been analysed to know the degree of strain of the existing REDs. With these measurements, the possibility of increasing the length of maximum free expansion of the deck has been examined and it has been proven to be possible as predicted strains were higher than the measured ones. Recommendations given have served to developed longer railway structures in Spain.Item Supervised Deep Learning with Finite Element simulations for damage identification in bridges(2022-04-15) Fernandez-Navamuel, Ana; Zamora-Sánchez, Diego; Omella, Ángel J.; Pardo, David; Garcia-Sanchez, David; Magalhães, Filipe; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThis work proposes a supervised Deep Learning approach for damage identification in bridge structures. We employ a hybrid methodology that incorporates Finite Element simulations to enrich the training phase of a Deep Neural Network with synthetic damage scenarios. The neural network is based on autoencoders and its particular architecture allows to activate or deactivate nonlinear connections under need. The methodology intends to contribute to the progress towards the applicability of Structural Health Monitoring practices in full-scale bridge structures. The ultimate goal is to estimate the location and severity of damage from measurements of the dynamic response of the structure. The damages we seek to detect correspond to material degradations that affect wide areas of the structure by reducing its stiffness properties. Our method allows a feasible adaptation to large systems with complex parametrizations and structural particularities. We investigate the performance of the proposed method on two full-scale instrumented bridges, obtaining adequate results for the testing datasets even in presence of measurement uncertainty. Besides, the method successfully predicts the damage condition for two real damage scenarios of increasing severity available in one of the bridges.Item Temporary cable force monitoring techniques during bridge construction-phase: the Tajo River Viaduct experience: the Tajo River Viaduct experience(2022-12) Gaute-Alonso, Alvaro; Garcia-Sanchez, David; Alonso-Cobo, Carlos; Calderon-Uriszar-Aldaca, Iñigo; Tecnalia Research & Innovation; E&I SEGURAS Y RESILIENTESThis article deals with the comparative analysis of current cable force monitoring techniques. In addition, the experience of three cable stress monitoring techniques during the construction phase is included: (a) the installation of load cells on the active anchorages of the cables, (b) the installation of unidirectional strain gauges, and (c) the evaluation of stresses in cables applying the vibrating wire technique by means of the installation of accelerometers. The main advantages and disadvantages of each technique analysed are highlighted in the Construction Process context of the Tajo Viaduct, one of the most singular viaducts recently built in Spain.