Discrete Element Modeling of Cone Penetration Tests Incorporating Particle Shape and Crushing

Abstract

The effect of particle shape and particle crushing on the results of cone penetration testing (CPT) of granular materials in a calibration chamber has been studied using three-dimensional discrete element modeling. Simulating the whole chamber with a realistic particle size requires a large number of particles, which leads to a large computational time. Both 90° and 30° segments of a calibration chamber were used in this study to reduce computational time. The effect of particle shape was simulated by prohibiting particle rotation or using simple two-ball clumps. Prohibiting particle rotation was found to increase tip resistance significantly compared with free particle rotation, and replacing a single sphere with different shapes of simple two-ball clumps was also found to have an important effect on the tip resistance. Particle crushing was simulated during CPTs by replacing a broken particle with two new equal-sized smaller particles. The results showed that there was a considerable reduction in the tip resistance for the crushing model compared with the noncrushing model, and this reduction increased as the confining stress increased.