Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential in The Niger Delta Region of Nigeria Using Standard Penetration Test-Based

Abstract:

This study aimed to evaluate the liquefaction potential of soils in Nembe Town, Bayelsa State located in the Niger Delta region of Nigeria through probabilistic and deterministic analyses using Standard Penetration Test (SPT) data. The objectives were to characterize the subsurface stratigraphy and soil properties through field and laboratory investigations, develop predictive models for soil parameters using a regional database, and apply simplified procedures to assess liquefaction risk. Ten borehole locations were selected across the town where SPT, undisturbed and disturbed sampling was conducted to a depth of 30m. Index tests classified the soils and determined density, plasticity and composition trends with depth. Shear wave velocity measurements aided subsurface profiling. Empirical predictive models through regression correlated key properties with stress factors demonstrating accuracy in characterizing limited site data. Simplified procedures using corrected SPT-N values classified the upper 30m as NEHRP Site Class D and evaluated the factor of safety against liquefaction. The extensive investigation program provided a robust framework for deterministic and probabilistic seismic hazard assessments through subsurface profiling and model validation. Results reliably characterized the deposit stratigraphy, compositions and properties to evaluate liquefaction potential in the Niger Delta region.