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.