Large-scale shallow foundation load tests on soft clay – At the National Field Testing Facility (NFTF), Ballina, NSW, Australia

This paper presents field test data from four instrumented rigid square pad foundations on soft clay that were brought to failure under concentric vertical loading. The test programme comprised two unconsolidated undrained (UU) foundation tests as well as two consolidated undrained (CU) tests. In the latter case the two foundations were preloaded to a proportion of the UU capacity and the soil was allowed to consolidate before being brought to undrained failure. In this paper, the site works and testing procedures are presented along with the load- and time-settlement responses of all four foundations. Horizontal stress and pore pressure data are presented for the two CU tests. The undrained and consolidated undrained load-settlement responses are shown to agree well with theoretical and numerical predictions. Results from the UU tests were the subject of a prediction exercise, summarised in a companion paper presented in this special issue.