Sample disturbances in laminated soils may be caused by several factors, including water movement between the clay and sand layers upon removal of overburden pressures. The research reported in this article examined the impact of this water movement on various geotechnical parameters. Samples of kaolin with laminations were formed, subjected to isotropic consolidation and subsequently sheared under undrained conditions. Further tests were carried out in which the samples were isotropically unloaded after consolidation and isotropically reloaded under undrained conditions, followed by undrained shearing. Tests were also carried out to examine the impact of unloading/reloading on the yield stress and small-strain stiffness. The results showed that the isotropic unloading/reloading process under undrained conditions led to reductions in the undrained shear strength, small-strain stiffness and yield stresses. Comparative tests carried out on unlaminated samples showed that the unloading/reloading process had a marginal impact on the above mentioned geotechnical properties.

中文翻译：

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由于消除了层压粘土中的围压而引起的样品扰动

叠层土壤中的样品扰动可能由多种因素引起，包括去除覆盖层压力后粘土和砂层之间的水运动。本文报道的研究检查了这种水运动对各种岩土参数的影响。形成具有叠层的高岭土样品，进行各向同性固结，然后在不排水的条件下剪切。进行了进一步的测试，其中固结后各向同性地卸载样品，并在不排水的条件下各向同性地重新加载，然后进行不排水的剪切。还进行了测试以检查卸载/重新加载对屈服应力和小应变刚度的影响。结果表明，在不排水条件下各向同性的装卸过程导致不排水剪切强度，小应变刚度和屈服应力的减小。对未层压样品进行的比较测试表明，卸载/重新装填过程对上述岩土性能有边际影响。