Evaluating Cracks and Structural Strength of Essential Educational Buildings Around Porac, Pampanga: Categorizing Retrofitting Requirements Through Color-Coded Mapping

Abstract

The Philippines, located along the Pacific Ring of Fire, is highly prone to seismic activity, with thousands of earthquakes occurring each year, some strong enough to cause significant damage and loss of life. One such event was the 2019 Luzon earthquake, which led to the collapse of the Chuzon Supermarket in Porac, Pampanga, highlighting the need to assess the safety of nearby structures, particularly essential facilities such as schools. This study evaluated the structural condition of three schools located closest to the collapse site—Porac National High School, Porac Model Community High School, and Pulung Santol National High School. Using Rapid Visual Screening (RVS), Pulung Santol National High School was identified as the most critical and selected for comprehensive evaluation. Crack mapping was performed using image-based analysis in MATLAB to obtain data on crack orientation, length, and thickness, while Non-Destructive Testing (NDT), including rebar scanning and rebound hammer testing, was conducted to determine the current compressive strength of cracked elements. A color-coded map was then created to visually present the retrofitting requirements of the assessed buildings. Structural elements with cracks were assigned specific colors based on severity and NDT results, to determine retrofitting required. This ensures that only parts requiring intervention are identified for more practical structural planning. The findings of this study aim to serve as a reference for future assessments and retrofitting prioritization, contributing to safer and more resilient educational environments in seismic-prone areas.