Diatomaceous soils: a new approach : Khilnani, K; Capik, M L Civ Engng, N YV59, N2, Feb 1989, P68–70

Abstract

Diatomaceous soils are formed over long periods of time when the skeletal remains of plankton and other single-celled marine creatures sink and accumulate in lakes, estuaries and oceans. The skeletons retain moisture, which is enclosed in a clayey matrix. These soils exhibit high in-situ moisture content, typically between 40% and 80%, much higher than the optimum moisture content for use as structural fills. A new density criteria is being used in Southern California, where these soils are prevalent. This approach meets code requirements and saves time and money. Engineers in the past have used air drying to deal with this moisture content problem. Significant air drying, requiring discing and processing in large stockpile areas of several hundred acres was necessary to bring soils for large-scale building projects to compactable range. The operation was also time-consuming and costly. The new approach was extensively laboratory and field tested and accepted by building officials. Technical data are given, and the performance of test fills described in detail. The need for monitoring and more research is emphasized.