Emilio Bastidas Arteaga | Université de Nantes (original) (raw)

Papers by Emilio Bastidas Arteaga

Marine Policy, 2019

Coastal flooding along the Atlantic coast caused by Storm Xynthia killed 41 people. The location ... more Coastal flooding along the Atlantic coast caused by Storm Xynthia killed 41 people. The location and configuration of residential housing were the main factors affecting the vulnerability of people to flooding. The French government responded by destroying buildings in the most flood-prone areas and relocating residents to safer areas. This strategy attracted much criticism, in particular because of the high costs involved with demolition on this scale, and that not insufficient consideration was given to other possible solutions. In this study, the goal is to compare different adaptation strategies in terms of cost of implementation and efficiency in order to reduce the vulnerability of houses to flooding. The strategies are grouped based on: (i) protection, (ii) relocation, (iii) housing architectural adaptation, and (iv) preventive warning and evacuation. This work is applied to La Guérinière, an Atlantic coastal town at risk of coastal flooding, although it was not impacted by Storm Xynthia. The initial results show that the most efficient strategy to reduce housing vulnerability to coastal flooding is also the most expensive. Ranked from the most to the least efficient and expensive, the strategies are as follows: (i) relocation, (ii) housing architectural adaptation, (iii) protection, (iv) and preventive warning and evacuation. Until now, these strategies have been limited as they omit human behaviour in response to coastal flooding scenarios. Therefore, this study examines the role of human behaviour in relation to different mitigative strategies. The efficiency and costs of the strategies are then reappraised.

This paper focuses on assessing the costs and effectiveness of climate adaptation strategies for ... more This paper focuses on assessing the costs and effectiveness of climate adaptation strategies for existing reinforced concrete structures subject to chloride penetration and climate change. We will focus on reinforced concrete structures built in France at different times under different building codes. With regard to environmental actions, historical meteorological data are used to estimate the current state of deterioration and several climate change scenarios will be considered for assessing the effects of climate change. It is hoped that the results of this study provide practical guidance to decision makers to improve the management of reinforced concrete structures under a changing climate.

Engineering Failure Analysis, 2021

A better understanding of the mechanical performance and the failure modes of corroded reinforced... more A better understanding of the mechanical performance and the failure modes of corroded reinforced concrete (RC) structures is crucial for implementing measures that reduce failure risks. Therefore, this paper proposes a probabilistic numerical framework to estimate the structural performance and to identify the failure modes as well as the main influencing parameters affecting the safety of corroded RC structures. This framework comprehensively combines experimental data, finite element method (FEM), and polynomial chaos expansion (PCE) modeling. First, the FEM for failure analysis is developed and verified with a 26-year-old corroded RC beam. The investigated case considers the effects of corrosion degree and bond behavior of the steel-concrete interface on the mechanical properties and failure mode of the corroded RC beam. Second, PCE surrogate models for serviceability and ultimate limit states are established by combining the sampling technique (e.g., Sobol sequences) and the validated FEM model. Finally, a global sensitivity analysis is conducted using the PCE model. Several illustrative cases are presented to analyze, in deterministic and probabilistic manners, the failure modes and the sensitivities of material properties and geometry characteristics for both serviceability and ultimate limit states. The results of this study could provide useful insights for understanding the main failure modes of RC structures under different corrosion scenarios.

Mechanics of Composite, Hybrid and Multifunctional Materials, Fracture, Fatigue, Failure and Damage Evolution, Volume 3, 2022

Over the Earth's history, the climate has changed considerably due to natural processes affecting... more Over the Earth's history, the climate has changed considerably due to natural processes affecting directly the earth. In the last century, these changes have perpetrated global warming. Carbon dioxide is the main trigger for climate change as it represents approximately up to 80 percent of the total greenhouse gas emissions. Climate change and concrete carbonation accelerate the corrosion process increasing the infrastructure maintenance and repair costs of hundreds of billions of dollars annually. The concrete carbonation process is based on the presence of carbon dioxide and moisture, which lowers the pH value to around 9, in which the protective oxide layer surrounding the reinforcing steel bars is penetrated and corrosion takes place. Predicting the effective retained service life and the need for repairs of the concrete structure subjected to carbonation requires carbon dioxide forecasting in order to increase the lifespan of the bridge. In this paper, short term memory process models were used to analyze a historical carbon dioxide database, and specifically to fill in the missing database values and perform predictions. Various models were used and the accuracy of the models was compared. We found that the proposed Stochastic Markovian Seasonal Autoregressive Integrated Moving Average (MSARIMA) model provides ! value of 98.8%, accuracy in forecasting value of 89.7% and a variance in the value of the individual errors of 0.12. When compared with the CO2 database values, the proposed MSARIMA model provides a variance value of-0.1 and a coefficient of variation value of-8.0 "# .

The mechanical and physical properties of timber structures could be affected by a combination of... more The mechanical and physical properties of timber structures could be affected by a combination of loading, moisture content, temperature, biological activity, etc. This paper focuses on the optimal design of new timber structures subjected to fungal decay. Among the optimization methods available in the literature, this study considers a Time-Dependent Reliability Based-Design Optimization (TD-RBDO) approach. The TD-RBDO aims at ensuring a target reliability level during the operational life by considering deterioration and the uncertainties related inherent to materials properties, models and climate. This approach is applied to design optimization of a timber truss subjected to an aggressive (very humid) French climate. The performance of the optimized solution is compared, in terms of safety, with solutions estimated from Deterministic Design Optimization (DDO) and Reliability-Based Design Optimization (RBDO) approaches. The overall results indicate that the optimized solution of...

The investigation of tropical behaviour woods in their environment is a real challenge for the pr... more The investigation of tropical behaviour woods in their environment is a real challenge for the prediction of the structural responses of tropical timber structures subjected to thermo-hygro-mechanical loadings. The present study is focused on the experimental characterization and modelling of the spatial variability of the physical-mechanical parameters (density, modulus of elasticity, compression and flexion) of a solid wood beam subjected to outdoor conditions in the south of Gabon into equatorial Region. Figure 1: (a) Beams in sheltered outside climate; (b) specimens, (c) cross-sections, (d) Spatial specimen modelling; (e) Experimental device modelling.

Engineering Structures, 2020

Reliability assessment of existing timber structures subjected to deterioration processes is an i... more Reliability assessment of existing timber structures subjected to deterioration processes is an important task to evaluate their serviceability and safety levels. Towards this aim, data collected after inspection campaigns are often used for updating structural reliability and planning future maintenance/inspection activities. Under natural conditions, timber decay involves a large number of uncertainties related to material properties and environmental exposure. These uncertainties are also affected by temporal and spatial variability of associated deterioration processes. In this context, the main objective of this study is to propose a Dynamic Bayesian Network approach for updating the structural reliability of deteriorating timber structures using inspection data. The proposed approach can account for the uncertainties in the decay process and the effect of spatial variability. It is also useful for reliability updating considering the uncertainties of inspection techniques. The proposed methodology is illustrated with the reliability updating of a timber beam subjected to decay deterioration. Results indicate that this approach is useful for evaluating and updating of structural reliability from spatially distributed inspection data. Reliability updating could also be carried out from partial observations at given areas, which is very useful for large-scale infrastructure.

Engineering Failure Analysis, 2018

Please cite this paper as: Wang XH, Bastidas-Arteaga E. Gao Y. (2017). Probabilistic analysis of ... more Please cite this paper as: Wang XH, Bastidas-Arteaga E. Gao Y. (2017). Probabilistic analysis of chloride penetration in reinforced concrete subjected to pre-exposure static and fatigue loading and wetting-drying cycles. Engineering Failure Analysis.

Reliability Engineering & System Safety, 2017

Electric power systems are vulnerable to extensive damage due to hurricanes with most of the dama... more Electric power systems are vulnerable to extensive damage due to hurricanes with most of the damage concentrated on overhead distribution systems. There is evidence that climate change will affect future hurricane patterns. Additionally, wood poles, which are most commonly used in distribution systems, are susceptible to decay. The scarcity of resources and increasing demand for higher reliability warrant the use of optimization techniques for wood pole maintenance planning. This paper presents a framework for optimal maintenance of wood poles subjected to non-stationary hurricane hazard and decay. Maintenance cost, service life, and system performance are considered separately and simultaneously in the optimization. Periodic chemical treatment and repair of decayed poles using fiber-reinforced polymer are considered. The distribution system of a virtual city assumed to be in Florida is used to demonstrate the framework. The results of the single-objective optimization indicate that the objective that maximizes service life resulted in higher optimal maintenance time. However, delaying maintenance will lead to a larger probability of pole failure, higher corrective maintenance cost, and lower system performance. The result of the multiobjective optimization is closer to the result of the cost-based optimization because the cost function is more sensitive to the variation of maintenance time.

Engineering Structures, 2016

Characterization of randomness and spatial variability of material properties, loading or deterio... more Characterization of randomness and spatial variability of material properties, loading or deterioration processes of structures, from inspection, is a very challenging task that concentrates the improvement of Non Destructive Testing (NDT) tools on more efficient and higher structural coverage. In case of characterization of random loading or material properties, this challenge is arduous because of the limited number of measures and the quasi-infinite potential positions of local failures. This paper presents a two stages procedure for the stochastic characterization of random fields from NDT measurements. According to the stationarity property, the optimal quantity of NDT measurements and their position can be assessed once a quality requirement is included. The proposed procedure allows: (i) to quantify the properties of the ergodic stationary field, and (ii) to assess the second order parameters of the studied random variables. The paper ends illustrating the methodology with an application that considers the inspection of a concrete beam with a capacitive technique. The results indicate that the proposed methodology is useful to identify the parameters of a random field by reducing the number of NDT measures under given quality requirements.

Civil Engineering and Environmental Systems, 2014

Bridge Maintenance, Safety, Management, Resilience and Sustainability, 2012

In corrosive environments, cover depth is one of the dominant parameters that controls time to co... more In corrosive environments, cover depth is one of the dominant parameters that controls time to corrosion initiation. Consequently, probabilistic modeling of this variable is essential to determine the performance of structures during the time. In this work, we study the influence of cover depth on probability of corrosion initiation. Towards this aim, we compare the effect of the models commonly used in probabilistic modeling with models determined from image analysis. Preliminary results illustrate the importance of accurate characterization of this random variable for a realistic assessment of structural lifetime.

souvent basée sur des critères économiques. Cet article propose une extension à des critères envi... more souvent basée sur des critères économiques. Cet article propose une extension à des critères environnementaux : la génération de déchets et le dégagement de CO 2. On s'appuie sur une problématique traitée dans le cadre du projet MAREO : la maintenance de structures en béton armé placées en ambiance maritime. Trois techniques de réparations sont comparées et leur performance est évaluée d'un point de vue fiabiliste. ABSTRACT. Maintenance optimization of infrastructures is generally based on cost functions. This paper suggests an extension of this analysis to environmental criteria: waste generation and CO 2 emission. This paper takes advantage of the MAREO project for the application to 1 RC structures placed in marine environment. Three repair techniques are compared and their reliability is evaluated from a stochastic modelling.

Beyond having provided critical evaluation of my work and exceptional professional and personal s... more Beyond having provided critical evaluation of my work and exceptional professional and personal support, they have consistently provided me with opportunities and encouragement that have allowed me to be self sufficient in carrying out my research. I would like to extend special gratitude to Dr. Franck Schoefs for inviting me to participate in his research group. His discussions and comments were important for the fulfillment of this project. Thanks to the active collaboration of several French research my research was greatly enhanced. I would therefore also like to mention the kindness and valuable discussions with various individuals:

Introduction 2 Reliability β ini β th Chloride-contaminated environments Repair or maintenance Re... more Introduction 2 Reliability β ini β th Chloride-contaminated environments Repair or maintenance Reliability of RC structures in chloride-contaminated environments Introduction Det. & maint deterioration model Optimal management Sustainable management Closure Problems with maintenance of corroding RC structures: There are no reliable models → to assess the performance during the operational life and to establish optimal management strategies Currently → corrective repair is carried out when visible signs of deterioration appear the expenditures cannot be predicted during the life-cycle and structural safety can be seriously compromised when repair is not undertaken Time (yr) 50-75 20-30 Optimal management Sustainable management Closure the lifetime distribution useful in problems where the states "functioning" and "failed" are well-defined © difficulties in defining failure for civil engineering problems → loss of serviceability, local failure (ULS) or total collapse © structures or structural components can be in different states Markov model structural conditions are discretized in various states widely used in management of civil engineering systems (e.g., PONTIS, KUBA-MS) effects deterioration, inspection and maintenance can be easily modeled © based on visual inspection or expert judgment © reliability is not directly incorporated /50 Deterioration and maintenance modeling Stochastic process (gamma process) Deterioration at time t → power law-i.e., at b for a, b > 0 COV → constanẗ simplified tool for optimizing the maintenance of critical components or prioritizing maintenance of structural networks when the mathematical properties of the stochastic process are well-known © it only focuses on one component, one failure mode and one uncertainty (COV of the deterioration process) Time-dependent reliability index Time-dependent reliability index Purpose → to minimize costs by ensuring an optimal level of safetÿ incorporation of the uncertainties related to material properties, environmental actions, load, inspection, repair, etc. consideration of various limit states (i.e., ultimate or serviceability) and failure modes © the effects of maintenance are difficult to estimate © time consuming Selected approach → Markov model Selected approach → Markov model /50 Conceptual framework of the proposed management strategy Definition of failure How to define failure? (collapse, loss of serviceability, loss of capacity, …) After discussion with the stakeholders (MAREO project) failure → corrosion initiation Repair criterion The structure is repaired before corrosion initiation /50 9 Maintenance strategy Stages of the maintenance strategy 1. Periodic inspection: chloride profiles → concrete cores /50 Stochastic processes 17 Stochastic model of weather (humidity and temperature): Karhunen-Loève expansion Seasonal trend Global warming Stochastic model of environmental chloride concentration: Introduction Det. & maint. Deterioration model Optimal management Sustainable management Closure Stochastic model of environmental chloride concentration: Uncorrelated log-normal fluctuations Exposure to de-icing salts Exposure to sea /50 Example: influence of global warming on corrosion initiation time 18 Objective: To study the influence of real weather conditions on both the probability of corrosion initiation and the lifetime reduction Objective: To study the influence of real weather conditions on both the probability of corrosion initiation and the lifetime reduction Description of the example: Studied environments: Climate Temp. (ºC) RH Continental: middle latitudes far-10 to 20 0.6 to 0.8 /50 30 Cost analysis Repair cost where n R is the annual number of repairs and k R is a coefficient to estimate the repair cost as function of C 0 Sustainable development [World commission on environment and development, 1987] : … development that meets the needs of the present without compromising the ability of future generations to meet their own needs… Components of sustainability → environment, economy, and society Sustainable development Environment Costs Assessment → model of inspection/maintenance Direct costs → inspection, repair and failure Real data → port of Nantes-St.-Nazaire and MAREO project Waste generation Concrete → 67% of waste of construction and demolition [American Institute of Architects, 1999] 5% recycled Cost Waste CO 2 Multi-objective optimization: compromise programming Multi-objective optimization: compromise programming Multi-criteria comparison: