Yielding and K0 Value Variation of Cemented Sand along a K0 Path

The yield stress and the coefficient of lateral earth pressure at rest, K-0, of soil are important parameters for geotechnical design. However, the effect of cementation on the values of yield stress and K-0 of artificially cemented sand along a K-0 path has not been fully studied, despite the common use of cement mixing for soil improvement. A series of consolidation tests of K-0 on artificially cemented sand has been conducted using a plane-strain apparatus. The test results show that the value of K-0 of cemented sand is very much affected by the amount of cementation; the lowest value of K-0 in a K-0 test corresponds to the yield stress provided by cementation. It is established in this study that the yield stress of cemented sand marks the start of a large amount of bond destruction. The value of K-0 reduces exponentially with the increase in cement content. One important practical implication is that the lateral earth pressure at rest can be reduced by introducing cementation to soil. This study also shows that Jaky's equation is no longer applicable for estimating the value of K-0 of cemented sand, although it may still provide a rough estimate for clean sand. The value of K-0 of cemented sand can be estimated using a combination of Jaky's equation for clean sand and Jaky's equation for cement content.