On the influence of platy shell particles on the cumulative deformations in sand under drained high-cyclic loading.

Abstract Mixtures of a fine sand with platy shell fragments have been tested under drained monotonic and high-cyclic loading. The content (0 to 40 %) and the size of the platy shell particles in the mixtures were varied. Comparative tests have been also performed on a mixture containing 40 % coarse sand and gravel particles instead of the shells. In the cyclic tests different stress amplitudes, initial relative densities and average stresses have been tested on the various mixtures. The strain accumulation rates were found to increase with growing content of shell particles. This can be primarily attributed to the more well-graded grain size distribution curves of the sand-shell mixtures. Particle breakage effects were almost absent in the cyclic tests as demonstrated by sieve analysis. Dependencies between the parameters of a high-cycle accumulation (HCA) model and the content of shell particles are analyzed. Amongst others, an extraordinary low dependence of the strain accumulation rate on strain amplitude (parameter C ampl < 1) has been observed for larger amounts of shell particles in the mixtures. Highlights • Mixtures of sand with different percentages of shell fragments have been produced. • They have been tested under drained monotonic and high-cyclic loading. • Strain accumulation rates increase with increasing content of shell fragments. • Direction of accumulation is almost independent of content of shell fragments. • No breakage of shell particles under high-cyclic loading has been observed. [ABSTRACT FROM AUTHOR]