Probabilistic assessment of the uncertainity associated with the pullout capacity of marquee ground anchors

Abstract

Marquees are light structures that are connected to the ground by tensile anchors to resist forces imposed by wind pressure acting on the structure. The current methods for predicting the ultimate pullout capacity of marquee ground anchors, based on the axial capacity of a single pile, are inaccurate and uncertain. This paper aims to quantify the uncertainty associated with the methods commonly used for pullout capacity prediction of marquee ground anchors. The study is concerned with a variety of ground anchors currently used in the Australian marquee industry. A series of in situ anchor pullout tests were conducted at six different locations in the Adelaide Region, South Australia, and the actual pullout capacity in each test is determined and compared statistically with the corresponding predicted pullout capacity of four methods currently used in practice. A probabilistic approach is used to determine the probability that the predicted pullout load exceeds a certain value utilising any of the methods considered. This approach is useful in that it enables the designer to make informed decisions regarding the level of risk associated with predicted pullout loads and, consequently, increase the safety of marquee structures.