Effect of Tip Angle on Cone Penetration Resistance: Insight from Model Test and DEM Analysis
Effect of Tip Angle on Cone Penetration Resistance: Insight from Model Test and DEM Analysis
The cone penetration test (CPT) is widely used to evaluate the mechanical properties of in-situ soil, where the measured cone tip resistance qc reflects soil strength. Although cone geometry is standardized, variations in cone tip angle significantly influence the stress field during penetration, leading to systematic differences in measured resistance. However, the combined effects of cone tip angle and stress level are not yet fully quantified. This study investigates the influence of cone tip angle on qc of sandy soil through physical model experiments and discrete element method (DEM) simulations. CPTs were conducted in a 1g model test using cones with different tip angles. The experimental results show that qc increases monotonically with increasing effective vertical stress for all cone geometries. At a given stress level, larger tip angles lead to higher qc, and this dependency becomes more pronounced under higher effective stress conditions. DEM simulations qualitatively capture these trends and provide micromechanical insights into the "shape effect" of the cone. The analysis reveals that blunter cones (larger tip angles) intensify vertical particle movement and contact pressure concentration near the cone shoulder, and vice versa. These findings demonstrate that qc is governed by the interaction between cone geometry and the localized stress field, providing a fundamental basis for interpreting CPT data when compared with other types of penetration tests with various cone configurations.
Ryo Nakamura; Masahide Otsubo; Rawiwan Sukhumkitcharoen; Akihiko Kondo; Itsuki Sato; O. Kurihara; Hidenori Takahashi
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 5: Combination of numerical and physical modelling
https://doi.org/10.53243/ICPMG2026-212