Seismic Vulnerability of Buildings in Palghar Area: Observations and Remedial Measures: Fid-Bau Portal

Seismic Vulnerability of Buildings in Palghar Area: Observations and Remedial Measures

Shinde, Rohan M. / Sinha, Ravi

Palghar district is a coastal district in Maharashtra and is located around 100 km to the north of Mumbai. A predominately tribal district, it has been experiencing frequent low-magnitude earthquakes. Over the last three years, the felt earthquake events number in hundreds. The felt shocks are generally in the earthquake magnitude range between 3 and 4, while a few larger shocks are between magnitude 4.0 and 4.5. The district is located in the seismic zone III as per IS:1893-2016, and is thus located in a region of moderate seismic hazard. There are a number of seismic faults and lineaments in the region. In addition to these, as the seismic sources in the region have not been comprehensively identified, there may also be unknown seismic faults contributing to the seismic risk. Even though the seismic events during the last three years have been of low intensity, the district administration has found that some buildings suffered structural damage. The frequent ground shaking had also resulted in widespread alarm in the area. Considering the seismic risk in the Palghar region, at the request of the Government of Maharashtra, IIT Bombay carried out a study to assess the potential seismic vulnerability of buildings. Using a visual seismic vulnerability assessment methodology developed at IIT Bombay, multiple field surveys were carried out in the affected areas. Initial pilot surveys were carried out by IIT Bombay along with the district administration of Palghar. The surveys focused on government buildings due to their importance from disaster management considerations. Subsequently, officers from the district administration along with government engineers from various line departments such as Public Works Department carried out this rigorous exercise of the field survey as per the methodology provided by IIT Bombay. Prior to the surveys, the government officers were also provided field training by IIT Bombay. The training program included understanding building types, their vulnerability to earthquakes and how to conduct a rapid visual survey (RVS) of buildings using the provided methodology. This paper presents salient details of the seismic hazard of the region, field survey, observations, recommendations and strengthening measures for predominant building types to enhance their safety.