Date of Publication

9-2024

Document Type

Master's Thesis

Degree Name

Master of Science in Civil Engineering

Subject Categories

Civil Engineering | Structural Engineering

College

Gokongwei College of Engineering

Department/Unit

Civil Engineering

Thesis Advisor

Lessandro Estelito O. Garciano

Defense Panel Chair

Andres Winston C. Oreta

Defense Panel Member

Bernardo A. Lejano

Richard M. De Jesus

Abstract/Summary

At present, the density and intensity of loadings experienced by structures have risen, and design regulations have become more meticulous. This study investigates the application of Operational Modal Analysis (OMA) and Numerical Modeling through ETABS software to obtain an accurate structural assessment of Henry Sy, Sr. Hall at De La Salle University Manila, a structure identified with a soft story. Enhanced Frequency Domain Decomposition (EFDD) and Stochastic Subspace Identification (SSI) methods are utilized to extract the structure’s modal parameters through obtained ambient vibration data. Afterward, ETABS is used for the modeling of the structure. The average frequencies obtained from the three deployments by OMA are 1.08, 1.56, and 1.74 Hz for SSI and 1.08, 1.46, and 1.75 Hz for EFDD. The fundamental frequency agreed with the height-period relationship proposed by Hong and Hwang (2000) with a percentage error of 6%. The software model presented frequencies of 1.20, 1.93, and 2.85 Hz for the first three modes. This presented percentage differences of 10.72%, 21.10%, and 48.08%, respectively. An additional deployment was conducted for supplementary verification of the data obtained, and it was found that the first two modes have differences of 9.45% and 2.49%, which are relatively small, but the higher modes have larger differences. This indicates noise in the signals obtained that affect the higher modes causing estimations that are less accurate. It was found that the frequencies of the numerical model are 10-20% greater compared to the experimental results from OMA and may indicate a change in the structural properties, but major factors have to still be considered such as modeling assumptions. Primary takeaways from the study include the investigation on the accuracy of OMA and found that there is high accuracy in determining the first two modes, but the estimation of higher modes have diminished accuracy. Additionally, the parameters obtained from OMA also serve as a benchmark on the structure’s dynamic properties in the current time. This research is a study that pioneers the approach of assessing a soft story structure in the Philippines through its dynamic parameters and contributes valuable insights to the field of structural health monitoring (SHM).

Abstract Format

html

Language

English

Format

Electronic

Keywords

Structural health monitoring; Structural dynamics

Upload Full Text

wf_yes

Embargo Period

9-28-2025

Download

Available for download on Sunday, September 28, 2025

Share

COinS