Failure Loads of Vertical Anchor Plates in Sand

There are many situations in civil engineering where vertical earth anchors must be used to withstand horizontal loading. A series of tests is described on model anchor plates in sand. The results are presented in the form of dimensionless force coefficients and shape factors relating failure loads to the geometry of the anchor and its depth of embedment. The method of stress characteristics is used to produce comparable theoretical values which agree well with experimental results at both model and field scales. The measured shape factors are independent of the size of the plate, and this contrasts with the force coefficients which decrease with increasing anchor size. A theoretical solution has been developed which allows φ to vary in a failure zone, depending on stress levels in the computations, and the effect is shown to be important. Difficulties in selecting suitable φ-values for design are outlined, and possible design procedures examined.