Typical features are descriptionbed of slides occurring in natural slopes of marine clay. This type of slide is characterised by the fact that the slides occur due to no apparent external causes, and also by the fact that, as the clay is involved in and remoulded by the slide, the shear strength is greatly lowered, and the clay assumes a fluid consistency.
Details were given of a large number of cases where micro-straining, had been successfully employed in overcoming, water, industrial effluent and sewage purification problems. A brief descriptionption was also given of equipment and filtering, media used, as well as the principles on which the design of the micro-straining, installations were based.
The object of this paper is to place on record the characteristics of the soils dealt with during the construction of two major airports. These characteristics are shown by the results of the soil tests carried out during the soil survey and during construction.