Evaluation of Spatial Distribution of Soil Strength inside Earth-fill Dams with Use of Geostatistical Method

Abstract

The spatial variability of the ground properties has been modeled as a random field, and the degree of the spatial correlation of the ground properties is represented by correlation length. Generally, determination of the correlation length is difficult, because the testing interval is too long. The purpose of this report is to prepare the basic data to appropriately evaluate the spatial variability of the soil strength by utilizing the correlation length of the soil strength inside an earth-fill dam. For this purpose, cone penetration tests (CPTs) were performed with short intervals at five earth-fill dams, and the correlation length of the soil strength of each the dam in the vertical and the horizontal direction was respectively estimated based on the maximum likelihood method and geostatistical method. As a result, it has been confirmed that the obtained correlation lengths are consistent with the values of the earth-fill dams and clayey soil shown in the past literatures. In addition, as an example to utilize the correlation distance, the evaluation of the spatial distribution of the soil strength inside a dam using the geostatistical method was presented.