SEISMIC FRAGILITY ANALYSIS OF PRE-ENGINEERED BUILDINGS (A CASE STUDY OF SUBSTATION GIS BUILDINGS)

Abstract

A Pre-Engineered Building (PEB) is a modern construction solution that involves designing and fabricating building components in a factory, then assembling them on-site. These structures are primarily made of steel and are widely used for industrial, commercial and institutional purposes due to their efficiency, cost-effectiveness and versatility. Electrical Substations are important component of electrical lifeline system of a country. Conventionally, Air Insulated Substations (AIS) have been installed at different voltage levels across the country. However, with the continuous increase in population and faster economic development, the pressure on land resources is increasing specially in the major cities. A Gas Insulated Substation (GIS) is a compact, high-voltage electrical substation that uses sulfur hexaflouride (SF6) gas as the insulating medium instead of air which is widely used in urban areas, industrial complexes and locations where spaces is limited. A GIS Building is required to enclose these GIS equipment and a Pre-Engineered Building (PEB) is generally being used to house these due to its advantages of cost-effectiveness, fast construction, customizability and durability in comparison with traditional RCC buildings. The members of Pre-Engineered Buildings are designed to align with the internal stress or bending moment diagram. PEBs represent a modern construction approach where the entire design is completed in a factory, and the building components are transported to the site for assembly. Eight such pre-engineered buildings (PEBs) being used in various substations in the country are considered for this vulnerability study using the fragility analysis method. Capacity and demand parameters were calculated by pushover and FNA time history analysis, while uncertainty parameters were taken from the HAZUS manual. An overall study showed that the pre-engineered buildings are less vulnerable to the earthquake. Therefore, these type of pre-engineered building can be utilized for post-earthquake temporary shelters and emergency response centers.