BSCE 2020, magna cum laude, Undergraduate Research Project Title: Analysis of Soil-Structure Interaction: A Parametric Study on the Dynamic Response of Elevated Structures Modelled as Lumped Mass on Single Piles due to Earthquake Loading using Direct Method

Abstract: Soil-Structure Interaction (SSI) analysis investigates the collective response of the interaction between three linked systems: the superstructure, the foundation, and the soil. The complexity of SSI is primarily due to its dependency on the key phenomena and parameters associated with the interplay between these three linked systems. The advancement of modern three-dimensional finite element tools makes it possible to investigate these complexities involving nonlinearities through the direct method approach which analyzes the entire soil-structure system response in one step. In this study, direct method was employed in a simplified model of an elevated structure on a single pile embedded in a homogenous soil medium subjected to El Centro (1940) ground motion. Results from the study showed that SSI causes the motion applied at the base of the structure to deviate from the free field response by inducing additional pile displacement characterized by a 13.64% increase in maximum pile displacement when the direct method was used. Moreover, a parametric study was conducted to determine which of the key parameters among the structure mass, column height, pile length, pile diameter, and soil type govern the SSI response. Results showed that for an elevated structure modelled as a lumped mass on a single pile subjected to earthquake loading, only the soil type has a noticeable effect in its SSI response. Hence, among the three linked systems, the soil medium has the most crucial effect on the collective dynamic response of the soil-structure interaction on these types of systems.

Keywords: Soil-Structure Interaction (SSI), Free Field Response, Direct Method, Elevated Structures

*This research project was co-advised with Asst. Prof. Giancarlo P. Ventura of Geotechnical Engineering Group (GEG)