Assessment and Retrofitting Augmentation Methods of Seismic Performance on Existing RC Buildings Across India

Abstract

One of the major tectonic plates in the world is the Indian tectonic plate bearing an area of 11,900,000 km². According to the Indian Standard Code of Practice (Bureau of Indian Standards (BIS) (2016) Criteria for Earthquake Resistant Design of Structures, 6th Revisi., vol. 1893, no. December. New Delhi), 60% of India’s geographical land lies under zones III, IV, and V (Murty, What are the Indian Seismic Codes?, IIT Kanpur. pp. 1–2). India has witnessed major earthquakes from time to time, over the past few decades. Over the period, the seismic performance of the existing buildings was assessed using various assessment methodologies. Diverse retrofit methods were experimented on various concrete components and were implemented on the impacted building elements. This paper talks about a detailed investigation of the failure mechanisms of the various reinforced concrete buildings of four major earthquakes spread across the country. The earthquakes spanning from Gujarat (2001, magnitude—7.7) in West to Sikkim (2011, magnitude—6.9) and Imphal (2016, magnitude—6.7) in North-East to Andaman and Nicobar Islands (2004, magnitude—8.7), the southernmost Union Territory of India, saw a similar failure mechanism in moment resisting reinforced concrete-framed buildings, despite lying on various seismic zones. Few retrofitting techniques that were applied to these deformed buildings are discussed in detail. From summarizing the diverse retrofitting approaches, it is found that the technique of concrete jacketing efficiently increased the performance of the buildings across the nation. It is one of the most suitable and common methods used employing local construction materials.