THE BEHAVIOUR ANCHORED SCREW PILES TO RESIST VERTICAL AND HORIZONTAL PULL-OUT PRESSURES

Abstract

Anchors, in general, are the structural elements used in civil engineering works to provide resistance against uplift forces . They are widely used to give stability to structures subjected to pull-out forces, such as transmission towers, pipe lines, aircraft moorings, radar towers, anchored floating equipment .....etc, as well as other types of hydraulic structures. These are usually subjected to storm waves, or difference in water levels that generate substantial tensile forces on their foundations. Other structures are subjected to direct flotation as docks and navigation locks .......etc.

The anchors, are either plate anchors, pile anchors, grouted anchors, single or multiple screw helical anchors. The main advantages of the single screw helical anchors are their simply manufacturing. Besides they can be effective immediately after installation for providing the required stabilizing effect against uplift forces. They are also easier to install .with light weight equipment, and their cost is less in cases of high underground water tables because dewatering will not be required.

The choice of the single screw helical anchor was due to the fact that the presented work is, qualitative rather than quantitative, in order to investigate the behaviour of the buried anchor afler failure, specially when subjected to big amounts of displacement. A sort • of practical understanding to its behaviour rather than comprehensive investigations, required to establish the theoretical basis for the actual resisting forces that can remain,