Properties of clay subjected to secondary compression and cementation

为了研究粘土在二次压缩和胶结作用下的性能。作者试图描述次生固结或胶结引起的准超固结粘土的不排水剪切行为。研究了具有不同塑性指标的未扰动海相粘土的抗剪强度。为了模拟现场正常固结和超固结情况，对扰动样在不同固结应力下进行了一系列三轴压缩试验。描述了二次压缩对粘土排水抗剪强度增加量的估算方法。通过直剪试验和三轴剪切试验，证明了该方法对重固结粘土和原状粘土抗剪强度增量的估计是有效的。此外，为了研究正常固结粘土的温度效应，进行了固结试验和三轴剪切试验。结果表明，加热引起的粘土体积变化与温度变化的增量成正比。根据上述结果，提出了温度作用下粘土屈服应力的预测方法。

In order to investigate properties of clay subjected to secondary compression and cementation. The author have attempted to describe the undrained shear behavior of quasi-overconsolidated clay induced by secondary consolidation or cementation.Shear strength of undisturbed marine clays with various plasticity indexes were investigated. A series of triaxial compression test were performed on disturbed sample under various consolidation stresses in order to simulated both normally consolidated and overconsolidated situation in the field.Method for estimating the amount of increase in undraind shear strength of clay due to secondary compression is described. The proposed method is proved to be valid for estimating the increase in shear strength of a reconsolidated clay and an undisturbed clay in direct shear test and triaxial shear test. Further, in order to investigate on temperature effects of normally consolidated clay, consolidation tests and triaxial shear tests were carried out. It was clear that volume change of clay induced by heating is in proportion to increment of temperature change. From the above results, method for predicting yield stress of clay subjected to temperature effects were proposed.