The Coefficient of Earth Pressure at Rest and Deformation and Densification of Granular Soils Subjected to Static and Dynamic Loading

Abstract

A comprehensive laboratory testing program, mainly the series of oedometer test with lateral stress measurement, were conducted on Ottawa, Lake Michigan Beach, Niigata, and Toyoura sand. Reconstituted dry sand specimens were subjected to 7 different loading histories, and the maximum effective vertical stress was 341 kPa. Different characteristics of dynamic vertical stresses, including periodic impulse stresses (f = 61 Hz, fp = 1,170 Hz), approximately sinusoidal dynamic stresses (f = 60 to 120 Hz, fp = 120 to 180 Hz), as well as 'cyclic loading' (loading-unloading-reloading, f ≈ 0 Hz), with various maximum dynamic stress amplitudes and durations of vibration, were applied to the sand specimens. A total of 155 oedometer tests with lateral stress measurement were completed. Particle modification, if any occurred during the oedometer test, was investigated through results of grain size and SEM analyses of sand particles before and after the oedometer test, and compression behavior of sand specimens observed during the oedometer test.