Rapid Visual Screening of Buildings in the City of Manila, Philippines

  • Dr Cesar Vallejo, Isabela State University, Ilagan Campus, Philippines

Rapid Visual Screening is a cheap and fast procedure in assessing the safety of buildings and classifying them according to the risk that they pose in times of strong earthquakes. In this project, it was used determine those mid and high-rise buildings in the City of Manila specifically in the university belt of Sampaloc area that are at high, medium and low risks. Data about the buildings were presented in a modified ATC 21 form which was used to classify the evaluated buildings. Visual inspection/pre-screening of the site and verification on the correctness of data gathered by interviewing building occupants or their neighbors were done. Structural indices were computed and the buildings were classified as to the risk they pose during strong earthquakes. Earthquake hazard maps were done reflecting the groupings of the buildings. The buildings evaluated in the area were predominantly mid-rise. Less than one-third of the buildings were classified as High Risk buildings and they were all Mid–rise and with Concrete Moment Resisting Frames. This confirms that most of the older or pre-code buildings have lower S-scores that was why many are in “High-Risk”. There is no way yet for humankind to predict the occurrence of the next strong earthquake and therefore a detailed inspection of the identified buildings in the High-risk group must be done the soonest time possible. Buildings with greater number of occupants must be prioritized in the detailed evaluation process to be able to save more lives in times of strong ground shakings.