Relative Weightage of Selected Structural Parameters on Overall Vulnerability of RC MRF Buildings

Abstract

Determination of seismic safety of existing buildings is a time consuming and challenging process. Instead, rapid visual survey methods were developed which also identify deficient structures from a large building stock in a city or town. These rapid visual screening (RVS) methods are quick and require minimal time. The important part of any RVS method is identifying critical architectural and structural features, i.e., irregularities (also known as vulnerable parameters). The score value assigned to each vulnerable parameter plays a vital role in deciding the risk of the building. Therefore, it also matters significantly that how these score values are derived. In the last two decades, several RVS methods were developed by many researchers and civil engineering professionals in India. newlineThe study in this thesis begins with a comparison and critical review of existing RVS methods used for seismic assessment of existing reinforced concrete buildings. The study focuses on rapid visual screening methods developed for the safety assessment of reinforced concrete buildings in the Indian subcontinent and a widely used method in the United States. The comparison is carried out in various ways. Initially, a direct comparison is made based on vulnerable parameters and damage grades proposed by each method. Later, a scoring system is developed to highlight the differences and rank the selected methods. It was observed that there are many uncommon vulnerable parameters amongst each selected method. Later, to understand the workability of each selected RVS method, a rapid visual survey was conducted on 100 reinforced concrete buildings in three different cities (viz., Pithoragarh, Gangtok, and Agartala) in India. The results of all five methods were found to have different outputs with significant variation for the same sample of surveyed buildings in each city. From investigation on such varying results, it was observed that relative weights assigned to each vulnerable parameter are different in each RVS method. Therefore,