A review of the existing studies relating to the uplift capacity of plate anchors embedded in saturated clay has been presented. The parameters controlling the mud suction force, net ultimate uplift capacity, and creep under sustained loading have been discussed.
Plate anchors are used in many instances in both onshore and offshore construction. The primary function of these anchors is to transmit the upwardly-directed forces Into the soil at a certain depth below the ground surface. Anchors have been used for thousands of years to stabilize structures subjected to uplift forces. However, most of the theoretical and/or experimental studies which have been undertaken to scientifically evaluate the holding capacity of anchors have been conducted during the last thirty years or so. Also, a review of the existing literature shows that most of the results published thus far on the ultimate and allowable capacities of anchors relate to those. In which the anchor is embedded In granular soil. Most of the findings presently available on the ultimate uplift capacity of plate anchors embedded In saturated and near-saturated clays were conducted as small-scale laboratory model tests. The purpose of this paper is to review some of the major aspects of the short-term holding capacity of plate anchors in clay (ф, = 0 condition) and make recommendations on possible areas of future research. GEOMETRIC PARAMETERS Figure I shows a plate anchor of Width B and length L, embedded In a saturated clay, being subjected to an uplifting force The depth of embedment of the anchor is H, and the undrained cohesion of the clay is Cu If the embedment ratio H/B is relatively small, at ultimate load the failure surface In the soil located above the anchor will extend to the ground surface. In very soft clays, the failure surface is nearly vertical, however, In medium stiff and stiff clays, it is curved as shown in Fig 1.
