Prediction of Long-Term Settlements of Foundations Supporting High and Heavy Storage Tanks Based on Short-Term Field Measurements

The operation and safety of high and heavy storage tanks are very sensitive to the differential settlements of the foundations. It is therefore extremely important to precisely predict the long-term settlements so that appropriate measures can be taken if the expected settlements are too large. Researchers have proposed different methods for predicting the long-term settlements of foundations. Of these different methods, the methods based on the short-term field measurements at the beginning, such as the Asaoka method, are commonly used. Since the measurements are taken at the site, the field conditions related to the structure, foundation and soils are well reflected in the measurements. However, since the measurements are only for a short period at the beginning, they may not reflect the behavior of the whole system at a significantly later time. This paper uses the extensive data of field settlement measurements for foundations supporting high and heavy storage tanks at an alumina refinery plant to do a detailed evaluation of the Asaoka method. Specifically, the measurements within different periods of time from the beginning are used to predict the settlements at a later time and the predictions are then compared with the measurements. By doing so, the effect of the time period from the beginning with field measurements on the accuracy of long-term settlement prediction is quantified. Finally, an optimum time period from the beginning with field measurements is recommended so that the field measurements can be used to predict the long-term settlement with sufficient accuracy.