In this paper, finite element analyses of plate anchor keying in Normally Consolidated (NC) clay were performed. Bearing capacity of plate anchors was investigated with various embedment ratios and pullout inclination angles. Both vented anchor base (no suction on rear face) and fully attached (bonded) anchor base were considered in the analysis. Anchor rotation was analysed using RITSS (Remeshing and Interpolation Technique with Small Strain model) method. It is found that the bearing capacities of inclined plate anchors are associated with both of the loading inclination angles and the anchor base conditions. The soil weight plays an important role in the bearing capacity analysis. The soil nonhomogeneity has minor effect on anchor rotational behaviour.
In recent years, oil and gas mining has moved into increasingly deeper water in search of undeveloped fields. For water depths in excess of 500 m, conventional platforms are replaced by floating facilities, anchored to the seabed using catenary or tautwire moorings. The latter type of mooring imparts significant vertical loading to the anchor, and consequently many different types of anchoring system have been developed (Ehlers et al. 2004). The SEPLA (Suction Embedded Plate Anchor) is one of such systems, which comprises a plate anchor that is penetrated in a vertical orientation using a caisson, and subsequently rotated by applying the anchoring force at some eccentricity until the plate becomes perpendicular to the applied force. This process is schematically illustrated in Fig. 1. It has been conceived to combine the advantage of suction caissons (known penetration depth and geographical location) and vertical loaded anchors (geotechnical efficiency and low cost). The uplift capacity of anchors in soil has been a subject of study for the last three decades, with the majority of past research being horizontal anchors pulled out vertically.
