First Advisor

Diane Moug

Term of Graduation

Spring 2026

Date of Publication

7-10-2026

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Civil & Environmental Engineering

Department

Civil and Environmental Engineering

Language

English

Physical Description

1 online resource (x, 82 pages)

Abstract

Oregon's Critical Energy Infrastructure (CEI) Hub in northwest Portland contains a large portion of the state's liquid fuel storage and distribution capacity and is located in an area susceptible to liquefaction and earthquake-induced permanent ground deformation during a Cascadia Subduction Zone earthquake. Initial Seismic Vulnerability Assessments submitted under Oregon's Fuel Tank Seismic Stability program provide valuable facility-specific information, but the assessments vary in subsurface characterization, treatment of fine-grained soils, ground motion selection, and deformation estimation methods. This variability complicates interpretation of regional seismic risk and motivates a consistent corridor-scale analysis.

This thesis develops CPT-informed displacement estimates for representative cross sections within the CEI Hub. The work builds from the nonlinear dynamic modeling framework developed for the 2021 Oregon Department of Defense CEI Hub study, which evaluated idealized uniform coarse-grained and fine-grained profiles. The present study extends that framework by incorporating spatially variable stratigraphy interpreted from FTSS SVA subsurface data. CPT-derived soil behavior type index, Ic, values were interpolated using a Python-based kriging workflow and simplified into sand-like and silt-like behavioral units suitable for two-dimensional nonlinear dynamic analysis. Sand-like units were modeled using PM4Sand and silt-like units were modeled using PM4Silt, with representative parameters adopted from prior CEI Hub modeling work. The representative sections were subjected to selected University of Washington M9 Cascadia Subduction Zone ground motions to evaluate lateral displacement response.

Results indicate that lateral displacement within the CEI Hub is controlled not only by proximity to the river free face and depth to bedrock, but also by the continuity and distribution of sand-like and silt-like units. Sections with interbedded stratigraphy produced different deformation patterns than the sand-dominated section, which exhibited the largest cumulative lateral displacement. These results suggest that stratigraphic interpretation can materially influence modeled displacement response and that additional CPT exploration would improve confidence in areas with sparse subsurface control. The corridor-scale framework developed in this thesis provides a consistent basis for interpreting variability among facility-level assessments and supports future probabilistic evaluation of liquefaction-induced displacement, soil-structure interaction, and infrastructure fragility within the CEI Hub.

Rights

© 2026 Ana Tijerina Esquino

Persistent Identifier

https://archives.pdx.edu/ds/psu/45060

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