Assessment of seismic building vulnerability based on rapid visual screening technique aided by aerial photographs on a GIS platform

作者：Rajarathnam S^*; Santhakumar A R

来源：Natural Hazards, 2015, 78(2): 779-802.

DOI：10.1007/s11069-014-1382-2

• Seismic risk
• RVS
• Aerial photograph
• Building vulnerability
• GIS database

The stability of buildings in seismic prone areas depends upon the structural behavior of buildings subjected to ground motion. Buildings of plan and vertical irregularities with respect to either geometry or stiffness have exhibited poor performance during past earthquakes . Identification of seismic building vulnerability is required for metropolitan cities which have moderate to high level of seismic proneness and have a high building density. Inspection of a large number of buildings individually requires enormous time and manpower. Using aerial photograph approach in GIS platform is an ideal choice to overcome these constraints. Chennai city is the thirty-fourth largest city in the world and prone to moderate earthquake hazards. This paper presents a methodology to analyze and predict the seismic vulnerability of buildings with five storeys and above in Chennai. Aerial photographic data of all buildings, land features and roads, within the city and its direct surroundings, were digitized and incorporated on a GIS platform, resulting in a digital vector map. A number of structural parameters determined on the basis of engineering knowledge and observations through rapid visual screening (RVS) have been used to identify the plan and vertical irregularities of the buildings. A new vulnerability scoring system to identify the level of damageability has been introduced based on RVS technique and compared with traditional grading system. Subsequent to RVS, a database of buildings having different range of vulnerability scores has been prepared. The percentage of desirable and undesirable features of buildings with respect to their contribution to damage was assessed based on past experiences and vulnerability scores of buildings. The survey shows that 30 % of the buildings are in the A category of being vulnerable to collapse. There are no buildings that can be classified as defect-free. It is also to note that 55-70 % of buildings lie in the category of D (low damage vulnerability).

• 出版日期2015-9