Santosh YADAV PhD graduate - December 2021

(CDP RISK - WP3)
PhD CDP Risk in 3SR Laboratory, Université Grenoble Alpes
Supervisors:
Yannick Sieffert (3SR, UGA, Yannick.Sieffert3sr-grenoble.fr (Yannick[dot]Sieffert[at]3sr-grenoble[dot]fr)),
Philippe Garnier (AE&CC, ENSAG, Philippe.Garnieruniv-grenoble-alpes.fr (Philippe[dot]Garnier[at]univ-grenoble-alpes[dot]fr)),
Florent Vieux-Champagne (3SR, UGA, Florent.Vieux-champagneuniv-grenoble-alpes.fr (Florent[dot]Vieux-champagne[at]univ-grenoble-alpes[dot]fr))

A lack of information for the structure's response

In 2015, there was a 7.8 Mw earthquake in Nepal, destroying more than 775000 buildings, and 9000+ people lost their lives. The geographical location of Nepal lies between two tectonic plates, which make the structures/building vulnerable to seismic events. Various strengthening techniques are available to minimize the damage to the structure; however, not all the approaches can be sustainable. Therefore, the authority again recommended the application of horizontal seismic bands during the reconstruction phase, which included the application of timber or reinforced concrete bands. However, there was a problem related to a lack of quantified information for the structure's response in case of future seismic events while using timber or reinforced concrete material as a band. Also, the cost of these materials varies significantly because of their availability and difficult terrain condition of the country. Therefore, the key purpose of this thesis was to study and compare the seismic vulnerability of two commonly used materials (timber and reinforced concrete) as a horizontal seismic band in masonry structures.

Major Contributions

    A multi-scale experiments approach was used to quantify the influence of band materials in the structure. Comparing the performance of two materials, the results using reinforced concrete were better than that of timber band. However, at the reduced scale building tested on the shake table, both structures with the application of seismic bands had repairable damage compared to one without a seismic band. Also, the most critical location for the application of seismic band is recommended through several analyses.
    Shake table and reaction frame setup were developed during this research work at 3SR, which will be used to characterize the behavior of different types of construction in the future.
    A new method was introduced to optimize the shake table usages times.

Local partners on the Nepal project

•     Architecture Sans Frontieres Nepal - Bangalamukhi, Lalitpur, Nepal
•     Institute of Engineering, Tribhuvan University - Pulchock, Lalitpur, Nepal
•     School of Engineering, Kathmandu University - Dhulikhel, Kavre, Nepal
•     Department of Urban Development & Building Construction - Kathmandu, Nepal

CDP RISK WP3 - Risk Assessment

WP3 is dedicated to develop innovative approaches to face challenges corresponding to modeling complex systems for vulnerabilities analysis & risk assessment ; and building some relevant risk indicators/metrics in a dynamical context together with decision functions. 

AE&CC research unit was involved in the reconstruction activity in Nepal with the collaboration of various stakeholders and local partners. The main challenge faced during the reconstruction phase was a lack of knowledge about the performance of the seismic band materials to make proper recommendations to the communities. As a request from the stakeholders to address this challenging question, AE&CC research unit collected all the relevant information from the site and collaborated with 3SR laboratory to address the issue with a scientific approach. Therefore, this experimental research work is carried out with the help of the interdisciplinary involvement of architects, engineers, and various stakeholders in Nepal.

1. Yadav, S., Sieffert, Y., Vieux-champagne, F.,  Debove, L.,  Decret , D., Malecot, Y. & Garnier, P. (2021). Optimization of the use time of shake table with specimen preparation outside the table surface [Submitting to Journal of Experimental Techniques]
2. Yadav, S., Sieffert, Y., Vieux-champagne, F.,  Malecot, Y., Hajmirbaba, M., Arléo, L., Crété, E. & Garnier, P. (2021). Shake table tests on 1:2 reduced scale masonry house with application of horizontal seismic bands [Submitting to Journal of Engineering Structures]
3. Yadav, S., Sieffert, Y., Vieux-champagne, F., Garnier, P.,  Hajmirbaba, M., Arléo, L., & Crété, E. (2021). Dynamic response of masonry structure with the application of horizontal seismic band: shake table tests [Submitted to 5th International Conference Structures & Architecture]
4. Crété, Eugénie, Julien Hosta, Eefje Hendriks, Aaron Opdyke, Santosh Yadav, Mampionona Rakotonirina, Olivier Moles, Prem Nath Maskey, Ramesh Guragain, Lumanti Joshi, Yannick Sieffert, Philippe Garnier, and Bill Flinn. (2021). “Incorporating Local Building Practices in Response.” Pp. 129–36 in Roadmap for Research: A Collaborative Research Framework for Humanitarian Shelter and Settlements Assistance.
5. Damerji, H., Yadav, S., Sieffert, Y., Debove, L., Vieux-champagne, F., & Malecot, Y. (2021). Design of a Shake Table with Moderate Cost. Experimental Techniques. https://doi.org/https://doi.org/10.1007/s40799-021-00482-0
6. Yadav, S., Damerji, H., Keco, R., Sieffert, Y., Crété, E., Vieux-Champagne, F., Garnier, P., & Malecot, Y. (2021). Effects of a horizontal seismic band on seismic response in masonry structure: Application of DIC technique. Progress in Disaster Science. https://doi.org/10.1016/j.pdisas.2021.100149
7. Crété, E., Yadav, S., Farahza, N., Arleo, L., Hajmirbaba, M., Sieffert, Y., & Garnier, P. (2020). Understanding traditional anti-seismic strategies beyond their disappearance and distortions: Yazd Qajar Architecture case study. In 12th International Conference on Structural Analysis of Historical Constructions.
8. Hosta, J., Garnier, P., Sieffert, Y., Yadav, S., Joffroy, T., et al.. State of knowledge and identification of research priorities for the scientific validation of disaster-resistant building cultures of the Himalayan regions of Nepal: Research report. [Research Report] CRAterre; AE&CC; CDP Risk. 2020, 60 p. ⟨hal-03116968⟩
9. Crete, E., Yadav, S., Sieffert, Y., Hajmirbaba, M., Hosta, J., Mendes, M. F., Garnier, P. (2019). Promoting Vernacular Architecture, A Basis for Building Back Safer? A Case Study from Nepal. In A. R; (Ed.), Structural Analysis of Historical Constructions (Vol. 18, pp. 2457–2465). Cusco, Peru: Springer. https://doi.org/10.1007/978-3-319-99441-3
10. Damerji, H., Yadav, S., Sieffert, Y., Vieux-champagne, F., & Malecot, Y. (2019). Damage Investigation Of Adobe Walls Using Numerical Damage Investigation Of Adobe Walls Using Numerical. In 7th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering.
11. Yadav, S., Sieffert, Y., Crété, E., Vieux-Champagne, F., & Garnier, P. (2018). Mechanical behavior of a different type of shear band connections being used in reconstruction housing in Nepal. Construction and Building Materials, 174, 701–712. https://doi.org/10.1016/j.conbuildmat.2018.04.121

. PhD MANUSCRIT
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