Damage scenario of reinforced concrete buildings in the 2015 Nepal earthquakes Rohit Kumar ADHIKARI 1 , Satish BHAGAT 1 and Anil C. WIJEYEWICKREMA 2 1 Graduate Student, Tokyo Institute of Technology, Japan [email protected], [email protected]2 Associate Professor, Tokyo Institute of Technology, Japan [email protected]ABSTRACT The Gorkha earthquake of April 25, 2015 and its aftershocks caused extensive damage to hundreds of thousands of building structures in Nepal. A reconnaissance survey was carried out in the most affected areas to assess the damage to buildings due to the earthquakes. It was found that many old as well as modern reinforced concrete buildings including residential, school and high-rise apartments sustained minor to major damage including collapse. Most of the well-designed reinforced concrete buildings sustained minor or non-structural damage. From the field observation, some of the main reasons of such a vast damage to building structures are found to be the lack of maintenance of old structures, negligence of building codes, and poor design and construction practices. This paper summarizes the damage to reinforced concrete buildings with specific focus on the causes and types of damage due to the earthquakes. Most of the collapsed reinforced concrete buildings were seen to have soft-first story failure mechanism. Non-structural damage mainly included heavy damage to the brick masonry infill walls. Suggestions and research needs are also identified to improve the seismic performance of reinforced concrete buildings in Nepal. Keywords: earthquake reconnaissance survey, reinforced concrete buildings, seismic damage, 2015 Nepal earthquake 1. INTRODUCTION A magnitude 7.8 earthquake occurred in the central region of Nepal on April 25, 2015 at 11:56 AM (Nepal Standard Time). The epicenter (28.147°N, 84.708°E) of the earthquake was located in the village of Barpak, Gorkha district which is approximately 77 km north-west of the capital city Kathmandu (Figure 1) and its focal depth was 15 km (USGS, 2015). The earthquake resulted in a maximum Mercalli Intensity of IX (Violent) and more than 8,700 deaths and over 22,300 injuries were reported. Some casualties were also reported in the adjoining areas of India, China, and Bangladesh. Over 350 aftershocks with magnitude greater than 4.0 have occurred, with some significant ones having a magnitude of 6.7 on April 26 and 7.3 on May 12 (Figure 1). More than 500,000 houses were totally collapsed and over 200,000 houses were partially damaged leaving over two million people homeless. Although Kathmandu and Sindhupalchowk districts were far away from the epicenter, severe damages were observed in these areas.
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Damage scenario of reinforced concrete buildings in the
2015 Nepal earthquakes
Rohit Kumar ADHIKARI1, Satish BHAGAT1
and Anil C. WIJEYEWICKREMA2 1Graduate Student, Tokyo Institute of Technology, Japan