This study investigates the seismic vulnerability of offshore pipelines, which are critical infrastructure for extracting marine geo-resources. Despite careful route surveys to avoid seismically active zones, pipelines sometimes must be laid in high-risk areas, exposing them to potential failure risks like pipeline buckling and soil liquefaction. The research employed numerical analyses using PLAXIS 2D finite element software, utilizing two advanced constitutive models in a two-dimensional plane-strain condition. The static phase was modeled using the hardening soil (small strain), in contrast the dynamic phase used the PM4Sand model to assess liquefaction potential and pipeline upheaval displacement. The study systematically varied key parameters including signal frequency (f), amplitude (a), and pipe embedment depth (H). Synthetic earthquake signals were used for easier parametric analysis, with results validated against previous research. Moreover, key findings reveal significant variations in liquefaction potential (ru) distribution within the soil body. The upheaval displacement (u) demonstrated interesting trends: it increased with signal frequency, initially decreased and then increased with signal amplitude, and consistently decreased with greater pipe embedment depth. Critically, the research found a direct correlation between upheaval displacement and liquefaction potential distribution. This comprehensive analysis provides crucial insights into offshore pipeline resilience, highlighting how different signal and installation parameters impact potential seismic risk and structural integrity. The study ultimately emphasizes the complex challenges in offshore pipeline design and the importance of comprehensive geotechnical and seismic considerations.