THE IMPACT OF SOIL CONSTITUTIVE MODEL SELECTION ON GROUND SURFACE SETTLEMENT ANALYSIS

Abstract

Choosing the appropriate constitutive model to analyze the ground surface settlement is essential. This study aims to predict ground surface settlement depending on groundwater level change in Bangkok, Thailand, by comparing two constitutive soil models. These are the Mohr-Coulomb model (MCM) and the Hardening Soil model (HSM). Simulations were conducted using PLAXIS 3D Version 2024 2.0 to analyze ground surface settlement trends. The results indicate that both constitutive models show a similar settlement trend during groundwater drawdown. During groundwater recovery and stable, HSM shows good agreement with measured data, which continues to settle with time. The ground surface settlement by HSM is 0.2 mm/yr. While MCM shows a rebound of ground surface elevation by the ground surface settlement rate is 0.05 mm/yr. Therefore, HSM can capture the ground surface settlement behavior of soft soil during groundwater fluctuation, which requires advanced parameters to analyze. MCM is suitable for preliminary analysis of simple issues or models that require only simple parameters and take less time to analyze.