Evaluating the coefficient of lateral stress at rest (K0 ) of granular materials under repetitive loading conditions

The coefficient of lateral stress at rest (K₀ ) is a very important soil parameter determining the in-situ stress states of soils. While the K₀ of soils under static loading conditions have been extensively studied, studies evaluating K₀ under repetitive loading have been very limited. This study aims at investigating the characteristics of K₀ of two granular materials with varying particle shapes during repetitive loading. The modified odeometer tests equipped with bender elements and diaphragm transducer were performed during static loading (-354.0 kPa), repetitive loading (Δσ’ = 176.6 kPa) and extra static loading (-706.9 kPa). The results of this study demonstrate that K₀ of tested materials increases with increasing cyclic loading number (i) though void ratio of tested materials continuously decreases with cyclic loading number. The stiffness anisotropy based on shear wave velocity measurements also confirms the finding of this study. Finally, the results of this study demonstrate that rounded granular material shows greater change in K₀ during repetitive loading compared to angular sand.