Bearing Capacity Of Rectangular Plate Anchor/Foundations In Normally Consolidated Clay

Abundant oil and gas could be found in the ocean,and the resources depleting in shallow water results in the exploration of gas and oil moving into deep water.The floating platforms are more adaptable to the deep and ultradeep water condition compared to the conventional gravity-based exploration platform,and new anchoring systems which have advantages of simpler operation and lower cost are required for the floating platforms.The plate anchor is economical with simpler shape.It has been widely used in both onshore and offshore mooring systems.Moreover,it is significant for other newly developed anchors(i.e.OMNI-MAX anchor and SEPLA)if its pullout behavior is better known.Many scholars have been focused on the issue of anchor pullout capacity.However,few studies have been concentrated on the pullout capacity of plate anchors with wide range of aspect ratios.Normally consolidated soil could be commonly seen in the seabed,it is of great importance figuring out the behavior of rectangular plate anchor in normally consolidated soil.Besides,the interpretation of data from site investigation is also crucial to the anchoring system,and the bearing capacity of foundations in the normally consolidated soil is related to the embedment depths which is also deserved to be concentrated on.The current paper focused on the rectangular anchors with wide range of aspect ratios and foundations with different shapes.Small strain finite element(FE)analyses based on ABAQUS are carried out to figure out the pullout capacity of plate anchors and foundations.The pullout capacity factors of rectangular anchors have been first derived with the numerical models,coupling effect of anchors inclinations,embedment ratios,the soil overburden pressure and non-homogeneity have also been taken into consideration.After verifying the results,new formulas on the pullout capacity factors with the above parameters have been proposed.Verification of the formulas has been conducted then,good agreement has been found between the estimated solutions and the published data.Moreover,outlier performance has been found for anchor with aspect ratio less than one.Bearing capacity of different shapes foundations embedded at large embedment depth has been focused on then.Smooth and rough interactions are implemented in the finite element models.The effect of the soil non-homogeneity has also been investigated.Results show that the bearing capacity increases with the increasing embedment depths even at large embedment depth,no critical embedment depths for ultimate bearing capacity has been found.The effect of the friction is more obvious for cone foundations than that for strip and circle foundations.The relationship between the soil non-homogeneity and the bearing capacity factors is related to the embedment depth.