FACTORS AFFECTING AT REST LATERAL STRESS IN ARTIFICIALLY CEMENTED SANDS

This paper presents the results of a laboratory study on the at-rest l ateral stress and K-0 of two artificially cemented sands. A modified o edometer ring was used to measure the lateral stress of cemented and u ncemented sands. Test materials were No. 3 Ottawa sand and a marine sa nd with portland cement. The specimens were prepared using the method of undercompaction to minimize the influence of specimen preparation o n test results. The cement contents were 0, 0.5, 1.0, 2.0, 4.0, and 8. 0% by the weight of dry sand. The water content of the specimens was 4 % of the weight of dry sand and cement. When the sands were cured unde r zero confining pressure, the test results indicated the following: t he at-rest lateral stress in cemented sands decreases significantly wi th increasing cement content; the relationship between the vertical an d at-rest lateral stress is nonlinear and the value of K-0 increases w ith increasing vertical stress; and the lateral stress decreases with sand density and curing period. When the specimens were cured under ve rtical stress, the value of K-0 during the removal of vertical loading increased with both overconsolidation ratio and cement content. Stres s history has a significant influence on the behaviour of at-rest late ral stress in cement sands.