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“...1007/S409 99-018-0297-9
RESEARCH PAPER
CrossMaik
Seismic Assessment of a School Building in Nepal and Analysis of Retrofitting Solutions
Hugo Rodrigues* 1 • Andre Furtado2 • Nelson Vila-Pouca2 • Humberto Varum2 • Andre R. Barbosa3
Received:25 September 2017 /Revised: 21 February 2018 / Accepted:27 February 2018 © Iran University of Science and Technology 2018
Abstract
Recent earthquakes highlighted the vulnerability of some infilled reinforced concrete structures due to the presence and distribution of the infill masonry walls. Buildings such as school buildings and residential buildings are typically not designed considering the contribution of the infill panels to the structure strength and stiffness, when these are subjected to earthquakes. The lack of consideration of the infill panel results in observed poor performance and structural collapses. This manuscript presents a numerical study of a school in Nepal, representative of those existent in the country. Non-linear numerical analyses were...”
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“...ons, infill masonry wall distribution, and varying seismic design [5-7]. Other research studies were directly related to the seismic behavior of structural elements [8].
Nepal is located in a region of high seismic activity, as evidenced by the various catastrophic earthquakes over recent years [9]. According to the Bureau of Crisis Prevention and Recovery of the United Nations Development Programme, Nepal, occupies the eleventh position on the list of most vulnerable countries in terms of seismic risk [10]. Recently, a quick and uncontrolled urban growth of the number of RC buildings was observed in Nepal. Consequently, notorious difficulties of the government in implementing building design codes accounting for seismic loads and/or the contribution of the infill masonry walls to the response has been lacking in Nepal. It is worth noting that most of the residential buildings and some important buildings, such as schools or government buildings were not designed according to the most recent...”
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“... in the direction of grid lines F and H shown in Fig. lb.
The main advantage of this solution is that it addresses the issue of the vertical irregularity of stiffness provided by the infill walls. However, the main disadvantage is on the impact of the functionality of the space. In the original building, the space where the walls are introduced corresponds to open space library for the students;
2. RC jacketing of all columns (RCJ): The RC jacketing of columns is a commonly used technique in Nepal as reported by Chaulagain et al. [31]. This retrofit solu-...”
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“...section adopted is 500 x500mm2. The added longitudinal reinforcing steel is 16-mm-diameter steel bars, while the transverse reinforcement corresponds to 8-mm-diameter reinforcing steel bars spaced at 125 mm on center, with two legs per face of the column, as shown in Fig. 11. Two different solutions were tested: (1) RC jacketing of all columns (RCI-TOT) and (2) RC jacketing of Storey 1 columns (RCI-GF).
3. Addition of steel braces (SB): The retrofit strategy using steel braces is not very common in Nepal, due to the high costs, lack of materials, and lack and skilled labor-associated use of steel. However, this enhanced seismic retrofit technique has proven their efficiency in past earthquakes [34],
The layout in plan and vertical distribution of the steel braces should be carefully analyzed to avoid inadequate stiffness irregularities that may cause undesired structural mechanisms [see Fig. 12), such as added torsion or even the soft-storey at other levels. The steel brace elements are usually...”
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“...yield higher reductions in peak drifts. Based on these results, the retrofit strategy that produced the best results was the addition of RC jacketing over the whole height of the structure. The retrofit solution with worst results was the addition of steel braces due to the high increase of the peak drift in the longitudinal direction (Storey 2) exceeding all the drift limits.
5 Conclusions
The main objectives of the manuscript were to assess the seismic vulnerability of a school building in Nepal and study the efficacy of different strengthening solutions to be applied. The analyses for evaluating the building and the respective strengthening solutions were based on state-of-the-art numerical models that consider the non-linear behavior of the structures when subjected to earthquake-induced ground shaking. The assessment methodology consisted of performing both non-linear static and non-linear dynamic analyses. Results from the non-linear dynamic analyses
indicated that the structure had...”
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“...(2015) Seismic risk assessment and hazard mapping in Nepal (in English) Nat Hazards, 78,1, pp 583-602
12. Shakya M, Kawan CK, Reconnaissance based damage survey of buildings in Kathmandu valley: an aftermath of 7.8 Mw, 25 April 2015 Gorkha (Nepal) earthquake Eng Failure Anal 59, pp 161-1842016
13. Gautam D, Rodrigues H, Bhetwal KK, Neupane P, Sanada Y (2016) Common structural and construction deficiencies of Nepalese buildings Innovative Inf Solut 1 (1):1
14. Varum H, Furtado A, Rodrigues H, Dias-Oliveira J, Vila-Pouca N, Arede A (2017) Seismic performance of the infill masonry walls and ambient vibration tests after the Ghorka 2015, Nepal earthquake”. Bull Earthq Eng 15,3, 1185-1212
15. SeismoSoft (2004) SeismoStruc- A computer program for static and dynamic nonlinear analysis of framed structures [online],” ed: Available from URL: http://www.seismosoft.com
16. Bose S et al. (2016) Structural Assessment of a School Building in Sankhu, Nepal Damaged Due to Torsional Response During the 2015...”
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