This paper investigates the elasto-plastic properties of soil layers and the propagation mechanisms of seismic waves in Namangan City (Islom Karimov Street) using 3D numerical modeling. The study is based on geotechnical data prepared by O‘ZGASHKLITI (2019) for the “Namangan Premium Investments” project. The 15-meter soil profile consists of topsoil (E=5 MPa), loess (E=25 MPa), sandy-gravel layer (E=80 MPa), and dense gravel (E=150 MPa). Using the PLAXIS 3D software, elasto-plastic modeling was carried out to analyze the deformation, velocity, and acceleration fields. The maximum deformation was 7.29 mm and occurred in the near-surface layers (0–1.6 m). Wave velocity decreased from 17.4×10⁻³ m/s at a depth of 5 m to 0.036×10⁻³ m/s at 20 m. Acceleration decreased from 0.35 m/s² to 0.12 m/s², indicating exponential energy attenuation with depth. The results show that upper layers with higher plasticity index (PI=12–18%) and lower elasticity modulus (E=5–25 MPa) strongly absorb wave energy, while the lower dense layers exhibit reflective behavior. The study provides valuable insights for seismic risk assessment, foundation design optimization, and enhancing the dynamic stability of soils.

elasto-plastic soil, 3D modeling, PLAXIS 3D, seismic wave, deformation, velocity, acceleration, energy attenuation, Rayleigh wave, Mohr–Coulomb model, Namangan, seismic stability.

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