Every Step I Take: Evaluating Stair Compliance At The UP Diliman Institute Of Civil Engineering Through Close-Range Photogrammetry

Abstract. This study explores the application of Close-Range Photogrammetry (CRP) for the structural assessment and compliance evaluation of stairs at the UP Diliman Institute of Civil Engineering. The analysis was performed on multiple flights of stairs, where scaling was done using a reference object due to the absence of ground control points (GCPs). For each step, three measurements were taken for both tread and rise dimensions and the average was computed to represent the values for consistency. Additionally, the standard deviation (SD) for both tread and rise within each flight was calculated to assess variability and conformity to the National Building Code of the Philippines (NBCP) standards. The results revealed significant variability in both tread and rise dimensions across the stairs. Only two flights of stairs out of twelve satisfied the 5 mm SD limit for tread, while none for rise. Ninety-three point sixteen percent (93.16%) fell outside the recommended tread range of 250-280 mm. The largest observed SDs were 11.16 mm for tread and 19.41 mm for rise, indicating considerable inconsistency in the stair dimensions. In terms of accuracy, the study validated the CRP method by comparing photogrammetry with actual physical measurements of the stairs. The Root Mean Square Error (RMSE) and Margin of Error (MOE) were used, yielding favorable results. The first stair demonstrated high accuracy, while the second showed minor variations that still fell within the lower end of the observed range, highlighting the reliability and precision of the measurement methods employed.