DEM analysis of cone penetration tests in pure and structured sand grounds

Abstract

In this paper, cone penetration tests (CPTs) were simulated in pure and structured sand grounds using PFC2D in 10 g condition. The structured sand ground was prepared by implementing a bond contact mode into the pure sand ground consisting of 300,000 particles, and the penetrometer moved downward at the rate of 0.5 m/s. The numerical results showed that with the normalized penetration depth increasing, the normalized tip resistance (qc /σvo) of structured sand ground increased and reached its peak value at first, and then decreased until a constant value was reached. The evolution of qc /σvo of pure sand ground was similar with that of structured sand ground, but the peak and constant values of the former were smaller than those of the latter. The velocity fields showed that particle velocities on both sides of penetrometer in structured sand ground were higher than those in pure sand ground. In structured sand ground, bonds were damaged during penetration process with bond breakage scarcely caused by tension or compression but mostly by shear force coupling with tension/compression.