The behaviour of anchor plates in clay

Abstract

The undrained behaviour of anchor plates with a vertical or horizontal axis, resting in a saturated clay, is examined. Theoretical consideration is given to the effects of anchor embedment, layer depth, overburden pressure and breakaway condition as well as anchor roughness, thickness and shape. The influence of these parameters on the failure mechanism and the anchor capacity is discussed. It is shown that in many cases ultimate collapse is preceded by significant anchor displacement and a definition of failure which allows reasonable displacement predictions to be made at working loads is proposed. Model tests for anchors with a vertical axis are reported. A comparison of these results and other published data with the theoretical solutions indicates encouraging agreement. The results of this study are presented in the form of charts which may be used directly in hand calculations for estimating the undrained failure load for anchor plates. L'article décrit le comportement non-drainé des plaques d'ancrage à axe vertical ou horizontal qui reposent dans l'argile saturée et décrit du point de vue théorique les effets de l'encastrement de l'ancrage, de la profondeur des couches, de la pression du terrain de couverture de la rugosité de l'épaisseur et de la forme de l'ancrage. L'influence exercée par ces paramètres sur le mécanisme de rupture et la charge utile de l'ancrage sont aussi discutées. On démontre que dans beaucoup de cas la rupture finale est précédée d'un déplacement significatif de l'ancrage et on propose une définition de la rupture qui facilitera la prévision raisonnable des déplacements sous charges de service. Un compte-rendu est donné de tests-modèles pour les ancrages à axe vertical. Une comparaison de ces résultats et d'autres données déjà publiées avec les solutions théoriques indique une correspondance encourageante. Les résultats de cette étude sont présentés sous la forme d'abaques qui peuvent être employés de façon directe dans des calculs manuels pour évaluer la charge de rupture des plaques d'ancragé dans des conditions.

Simplified design methods for pipelines subject to transverse and longitudinal soil movements

“…I. Numerical solutions developed by Rowe and Davis (1982) for cohesive soils can be used to evaluate the ultimate ' " ground surface…”

“…Rowe and Davis (1982) showed that the ultimate soil resistance is dependent on the embedment depth and the degree of bonding between the back of the pipeline and the soil. Figure 3 shows the solutions developed by Rowe and Davis (1982).…”

“…Rowe and Davis (1982) showed that the ultimate soil resistance is dependent on the embedment depth and the degree of bonding between the back of the pipeline and the soil. Figure 3 shows the solutions developed by Rowe and Davis (1982). For an embedment ratio (h/b) of 2, the ultimate soil resistance, R, is essentially 4bs u when the soil separates from the back of the pipe, and 9bs u when no separation occurs.…”

“…The transverse (uplift or lateral) response of the pipeline to landslide movement was obtained by solving the general analytical solution described by Rajani and Morgenstern (1993) Ｈ ｾ particular values of pipeline-soil resistance factors, No, developed by Rowe and Davis (1982) (Fig. 3).…”

“…This means that the pipeline embedment ratio, hlh, defined as the ratio of depth to the base of the pipeline and the soil cover, is typically about 2 or very near this value. Based on solutions prOVided by Rowe and Davis (1982) (Fig. 3), the resistance factor N e can vary from 4 to 9 depending on whether soil separation occurs or not at large displacement.…”