Grasping of Aging in Naturally Deposited Clays and its Duplication in Laboratory

为了掌握自然沉积粘土的老化效应，建立实验室老化效应的复制方法，本研究按照以下三个步骤进行。研究了具有老化效应的自然沉积粘土的力学性能，并考虑了老化效应的定量评价方法。结果表明，在考虑破坏斑量的情况下，用抗剪强度与孔隙率的关系可以定量地评价老化效应。为了定量评价粘土的微观结构，提出了一种计算机图像处理方法。用该方法测量了扫描电镜照片的密度分布，并对其功率谱进行了分析。澄清了高温固结土的力学性能和微观结构，并与室温固结土和未受扰动的天然粘土进行了比较。结果表明，高温重固结土具有随机结构，室温重固结土具有定向结构。由于自然沉积粘土的微观结构是随机结构，因此高温再固结过程不仅在力学性能上而且在微观结构上都可以复制老化效应。

In order to grasp aging effects in naturally deposited clays and develop a duplication method of the aging effects in laboratory, this study was carried out in accordance with the following three steps.1.Mechanical properties of the naturally deposited clays possessing the aging effects were investigated and quantitative evaluation methods of the aging effects were considered. As the results, it was found that the aging effects can be quantitatively evaluated by shear strength versus void ratio relationships in which the amount of the failure stain were considered.2.A computer image processing method was developed in order to evaluate quantitative microstructures of clays. Density distributions of Scanning Electron Microscope photographs were measured and their power spectrum were analyzed in this method.3.The mechanical properties and the microstructures of clays reconsolidated at a high temperature were clarified and compared with those of clays reconsolidated at a room temperature and undisturbed natural clays. As the results, it was found that the high temperature reconsolidated clays have a random structure and the room temperature reconsolidated clays have an oriented syructure. As the microstructure of the naturally deposited clays are random structures, the aging effects can be duplicated by the high temperature reconsolidation procedure in terms of not only mechanical properties but also microstructures.