Browsing by Author "Alrubaye, Maryam"

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Citation - WoS: 1
Citation - Scopus: 1
Process Simulation of Pseudo-Static Seismic Loading Effects on Buried Pipelines: Finite Element Insights Using RS2 and RS3
(MDPI, 2025) Alrubaye, Maryam; Sengor, Mahmut; Almusawi, Ali
Buried pipelines represent critical lifeline infrastructure whose seismic performance is governed by complex soil-structure interaction mechanisms. In this study, a process-based numerical framework is developed to evaluate the pseudo-static seismic response of buried steel pipelines installed within a trench. A comprehensive parametric analysis is conducted using the finite-element software Rocscience RS2 (version 11.027) to examine the influence of burial depth, pipeline diameter, slope angle, groundwater level, soil type, and permanent ground deformation. The seismic loading was represented using a pseudo-static horizontal acceleration, which approximates permanent ground deformation rather than full dynamic wave propagation. Therefore, the results represent simplified lateral seismic demand and not the complete dynamic soil-structure interaction response. To verify the reliability of the 2D plane-strain formulation, a representative configuration is re-simulated using the fully three-dimensional platform Rocscience RS3. The comparison demonstrates excellent agreement in shear forces, horizontal displacements, and cross-sectional distortion patterns, confirming that RS2 accurately reproduces the dominant load-transfer and deformation mechanisms observed in three-dimensional (3D) models. Results show that deeper burial and stiffer soils increase shear demand, while higher groundwater levels and larger permanent ground deformation intensify lateral displacement and cross-sectional distortion. The combined 2D-3D evaluation establishes a validated computational process for predicting the behavior of buried pipelines under a pseudo-static lateral load and provides a robust basis for engineering design and hazard mitigation. The findings contribute to improving the seismic resilience of lifeline infrastructure and offer a validated framework for future numerical investigations of soil-pipeline interaction.
Pseudo-Static Finite-Element Assessment of Seismic Soil-Pipeline Interaction in Multi-Line Buried Pipelines
(MDPI, 2026) Sengor, Mahmut; Alrubaye, Maryam; Almusawi, Ali
This study investigates the seismic response of double- and triple-buried steel pipeline systems using finite-element modeling in RS2, with particular emphasis on soil-pipeline interaction and symmetry-breaking behavior under pseudo-static seismic loading. Although the pipeline systems are initially symmetric in geometry, material properties, and boundary conditions, the analysis demonstrates that directional seismic excitation induces quantitatively measurable asymmetric responses in shear force, displacement, and spacing due to nonlinear soil-pipeline interaction. Five parametric scenarios were examined, including burial depth (1-5 m), pipeline diameter (8-56 in.), groundwater table (1.4-20 m), peak ground acceleration (0.1-0.6 g), and soil type. The results show that maximum shear forces increase with burial depth and diameter, reaching approximately 15-17 kN in clayey soils at a PGA of 0.4 g, whereas sandy and heterogeneous soils produce lower shear forces (approximate to 12-14 kN). Horizontal displacements are strongly governed by groundwater and PGA, increasing from about 1.2-1.8 m in dry or deep groundwater conditions to more than 2.8 m for shallow groundwater and exceeding 5 m at PGA = 0.6 g. Triple-pipeline systems exhibit higher shear demand due to confinement effects, with the middle pipeline often developing the largest shear force, while the pipeline facing the seismic load consistently experiences the greatest displacement. This study makes two primary contributions. First, it demonstrates that initially symmetric multilined buried pipeline systems exhibit systematic, quantifiable symmetry-breaking behavior under directional seismic loading, manifested as unequal shear forces, displacements, and interaction effects among adjacent pipelines. Second, it presents an integrated multi-parameter coupling analysis that simultaneously accounts for burial depth, pipeline diameter, groundwater level, soil type, and peak ground acceleration, revealing interaction mechanisms that cannot be captured through single-parameter or single-pipeline assessments.