Effect of sand overconsolidation and extensive liquefaction on K₀

In the first part of this research, centrifuge model testing was used to investigate the relationship between the coefficient of lateral earth pressure at rest, K₀, and overconsolidation ratio, OCR, for clean sand for the whole loading-unloading-reloading cycle. Tactile pressure sensors were used to measure the change in K₀ in two saturated centrifuge models conducted on Ottawa sand. A relationship was developed between the change in K₀ and OCR both for unloading and reloading conditions. In the second part of this research, the same tactile sensor was used to test the influence of extensive liquefaction on K₀. A centrifuge model was subjected to very strong shaking causing extensive liquefaction. Lateral earth pressure was measured before and after liquefaction. It was found that there is a significant reduction on K₀ due to extensive liquefaction which explains the increased vulnerability of sandy deposits after liquefaction, as observed by many researchers.