Pullout resistance of single vertical shallow helical and plate anchors in sand

Abstract

This paper presents analytical models to predict the pullout capacity and the load-displacement relationship for shallow single vertical helical and plate anchors in sand. The models were developed based on the failure mechanism deduced from laboratory testing and utilize the limit equilibrium technique. Expression was given to estimate the critical depth for a given anchor/soil conditions, which separates deep from shallow anchors. Furthermore, the radius of influence of a individual anchor on the ground surface is established, and accordingly, the spacing between anchors can be determined to avoid anchors interactions between anchors. The proposed theory compared well with the theories and the experimental data available in the literature.Résumé Cet article présente un model analytique pour prédire la résistance à l'arrachement et la relation charge-diplacement pour les ancrages à vis et plats verticaux superficiels ancrés dans le sable. Le model est basé sur le mécanisme de rupture déduit des essais de laboratoire et utilise la méthode d'analyse à l'équilibre limite. En outre, une expression a été proposé pour éstimer la profondeur critique pour un ancrage donné permettant d'identifier l'ancrage comme superficiel ou profond. Le rayon d'influence d'un ancrage à la surface du sable autour de l'ancrage a été établi, et par conséquent, l'espacement entre ancrages peut être déterminer pour éviter toute interaction. La théorie proposée montre une bonne concordance avec des résultats theoriques et expérimentaux rapports dans la literature.

Effect of soil deformability on the failure mechanism of shallow plate or screw anchors in sand

“…The anchor uplift capacity is derived from the equilibrium of a rigid soil body delineated by a given failure surface. At shallow depths, the failure surface is a soil wedge reaching the surface, whose boundary may be assumed to be a straight line, either vertical or inclined, (Meyerhof and Adams 1968, Ghaly et al 1991, Giampa et al 2017 or a log-spiral (Murray and Geddes 1987, Saeedy 1987, Hanna et al 2007 propagating from the plate to the soil surface ( Figure 1Figure 1). At greater depths, a flow around mechanism has been proposed, consisting of a deep wedge that does not reach the ground surface (Meyerhof andAdams 1968, Ghaly et al 1991).…”

New mitigation method for pipeline uplift during seismic event

“…The small difference (2 mm) between the lengths of the box and the plate eliminated the friction between these two elements during the uplift. The boundary effects were reduced considering the fact that the depth of embedment of the plate was shallow (H/B < 1·5) (Hanna et al, 2007) and also because the affected area at the surface of the embedment was limited to a small area compared with the total width of the box.…”

The Criterion for Determining the Ultimate Pullout Capacity of Plate Anchors in Clay by Numerical Analysis

“…Hanna et al (2007) investigated the load-displacement curve derived by Ghaly et al (1991) in model tests. A hyperbolic curve was adopted to fit the measured result, which is Equation 1:…”