Evaluating the Seismic Performance of Domestic and Historical Masonry Structures in Himachal Pradesh Region of India

Abstract

The state of Himachal Pradesh in India is located along the foothills of the Himalayas comprising steep terrain, mountainous region and valleys. Approximately 70% of the residential and heritage buildings in the region are made of unreinforced masonry constructed using locally available materials such as mud bricks, stones and timber composites. The region is seismically active and has already witnessed strong earthquakes causing huge loss of lives and livelihoods. Hence understanding the seismic performance of unreinforced masonry structures is important to ascertain the safety of these structures in the event of a future earthquake. With the ultimate aim to co-produce methodologies to evaluate and improve the seismic safety of lives and livelihoods in the region, this study presents the results of an extensive survey of domestic and heritage unreinforced masonry structures. One of the common structural typologies in the region is the Kath-kuni architecture of Himachal Pradesh; also called Tower Temples. Stonemasonry serves as a main load-bearing stratum and the geometric form of these structures is symmetrical which makes them less vulnerable to earthquakes. However, non-uniform mass distribution was observed along with the height of the structures, i.e., having higher mass lumped at a greater height, which reduces the ability of the upper portion of the structures to withstand the lateral force during an earthquake. Age-related deterioration of structural members was observed in some of the structures due to the lack of regular maintenance. This study concludes by suggesting options that could safeguard these structures in the event of future earthquakes.