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PhD Thesis: A framework to assess climate change effects on bridges subjected to progressive deterioration and extreme events CDD

Contact

Bastidas-Arteaga Emilio
2, rue de la Houssinière BP 92208
44300 Nantes
1
France
0251125524
emilio.bastidas@univ-nantes.fr

Descriptions

Établissement :
UN - Université de Nantes
Laboratoire :
Rémunération mensuelle :
1789€ (Brut) €
Date de début :
01/09/2019
Date de fin :
31/08/2022
Date limite pour postuler :
07/06/2019
Descriptif :

Context of the PhD topic

Civil infrastructure systems are critical assets for the socioeconomic development of any country. Designing and maintaining these systems for a particular service lifetime have been recognized as critical issues worldwide [1]. RC structures are characterised by high durability; however, during their operational life, they are subjected to internal and external actions as well as extreme events that affect their performance, serviceability and safety [2]. Nowadays, many deteriorated structures are evaluated for possible repair and continued service because their replacement would be economically unfeasible. For example, about 173,000 bridges in the United States are structurally deficient or functionally obsolete due in part to corrosion [3]. Regarding costs, Koch et al. [4] found that the global cost of corrosion is US$2.5 trillion (about 3.4% of the global Gross Domestic Product). Thus, developing robust models for lifetime prediction and strategies for periodic inspection and maintenance plays a significant role in enabling target reliabilities to be met over a period of continued service [1,5].

 

This Ph.D. thesis will be carried out in the framework of the INTERREG SIRMA (Strengthening the territory’s resilience to risk of natural, climate and human origin) 2019-22 project. This Ph.D. thesis will focus on the assessment of consequences on deteriorating bridges subjected to the combined action of progressive (deterioration due to chloride ingress and atmospheric corrosion [6–8]) and sudden (scour) events [10]. Experimental evidence indicates that the deterioration processes (chloride ingress and corrosion) are influenced by the weather conditions at the surrounding environment – i.e. temperature and humidity. Since climate change studies predict several changes in the climate [9], these climate variations could accelerate deterioration consequences. In addition, the risk of scour of bridge piers and abutments could be larger because climate change predictions announce more frequent and more intense river flooding due to the expected increases in precipitation in the future [10]. Therefore, a comprehensive lifetime assessment or reliability analysis should integrate these effects of climate change.

 

Objectives

The main objective of the thesis will be to propose an original methodology to evaluate the vulnerability of bridges to progressive deterioration  and sudden (scour) events under various climate change scenarios. Progressive deterioration will be initially represented by a deterministic function. Randomness will be later included as a shock process with times between random deterioration jumps described by a suitable deterministic function. Sudden events will conform to a compound point process with shock sizes and interarrival times that are independent and identically distributed random variables. The proposed methodology will be applied to different places in the Atlantic area by considering typical steel and reinforced concrete structures.

 

 

 

 

Main Tasks

The main task of the working plan are summarised  as follows:

  • Literature review about the deterioration models and stochastic tools that will be used for lifetime assessment.
  • Establishment of a climate database for structural lifetime assessment under climate change scenarios.
  • Development of a stochastic model for extreme events (i.e. maximum annual river flow).
  • Development of a methodology for lifetime assessment taking into account the combined action of progressive (deterioration)  and sudden (scour) events.
  • Application to case studies.
  • Dissemination of the main results in the forms of: reports, conference and journal papers.

 

Candidate profile

  • Background: Civil or Mechanical engineering. However, good knowledge on bridge engineering and experience in stochastic, probabilistic and reliability methods will be much appreciated.
  • Scientific programming: ability to program in a scientific programming language such as C/C++, Fortran, Matlab.
  • Communication: excellent writing and presentation skills in English to be able to interact with other partners of the SIRMA project. The collaborative work could require short stays in the partner institutions.

 

Conditions

  • Type of contract: Full time doctoral contract for 36 months starting since September 2019
  • Salary: 1789€/month (gross) or ~1433€/month (net)
  • Location: University of Nantes, Nantes campus, France

 

Application procedure

Please send a curriculum vitae, motivation letter, marks, and two recommendation letters to E. Bastidas-Arteaga (emilio.bastidas@univ-nantes.fr) before June 7th 2019.

 

References

[1]            Bastidas-Arteaga E, Schoefs F. Sustainable maintenance and repair of RC coastal structures. Proc. Inst. Civ. Eng. - Marit. Eng. 2015;168:162–173.

[2]            Sánchez-Silva M, Klutke G-A. Reliability and Life-Cycle Analysis of Deteriorating Systems. Cham: Springer International Publishing, 2016.

[3]            Bhide S. Material Usage and Condition of Existing Bridges in the {U.S.}. Skokie, Ill: 1999.

[4]            Koch G, Varney J, Thompson N, Moghissi O, Gould M, Payer J. International Measures of Prevention, Application, and Economics of Corrosion Technologies Study. NACE International IMPACT Report, Houston, TX 77084: 2016.

[5]            Mori Y, Ellingwood BR. Reliability-based life prediction of structures degrading due to environment and repeated loading, in: M. Lemaire, J.L. Favre, A. Mébarki (Eds.), Appl. Stat. Probab. Civ. Eng. Reliab. Risk Anal., Paris, France: Balkema, 1995: pp. 971–976.

[6]            Saetta A, Scotta R, Vitaliani R. Analysis of chloride diffusion into partially saturated concrete. ACI Mater. J. 1993;90:441–451.

[7]            Nguyen P-T, Bastidas-Arteaga E, Amiri O, El Soueidy C-P. An efficient chloride ingress model for long-term lifetime assessment of reinforced concrete structures under realistic climate and exposure conditions. Int. J. Concr. Struct. Mater. 2017;11:199–213.

[8]            Bastidas-Arteaga E, Stewart MG. Economic Assessment of Climate Adaptation Strategies for Existing RC Structures Subjected to Chloride-Induced Corrosion. Struct. Infrastruct. Eng. 2016;12:432–449.

[9]            IPCC. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press, 2013.

[10]          Imam B. Chapter Six – Climate Change Impact for Bridges Subjected to Scour and Corrosion, in: E. Bastidas-Arteaga, M.G. Stewart (Eds.), Clim. Adapt. Eng., 2019: pp. 165–206.

Mot(s)-clé(s)

  • Analyse des risques
  • Durabilité
  • Infrastructures
  • Modélisation