Analytical study on the ultimate embedment depth of drag anchors

The ultimate embedment depth (UED) is a very important index in evaluating the performance of drag anchors, and hence is of necessity to evaluate the UED precisely in design and analysis. On the other hand, the UED is also a key parameter in predicting the kinematic trajectory of drag anchors in soils by numerical or analytical methods. In this paper, analytical derivations are developed to express the UED not only in clay but also in sand. By analyzing and describing equilibrium forces acting on the anchor and embedded drag line, and the interaction between them at the UED, concise expressions are formulated for predicting the UED in terms of characteristics of the anchor, drag line and soil. Considering that the exact values of the various parameters are seldom known, a parametric analysis is performed systematically. In order to check the applicability and precision, expressions of the UED in clay are compared comprehensively with the other prediction methods. Specially designed tests are also carried out in a model experimental system, and the measured data are used to examine the expression of UED in sand.