R. Sundaravadivelu

Bio: R. Sundaravadivelu is an academic researcher from Indian Institutes of Technology. The author has contributed to research in topics: Embedment & Fin. The author has co-authored 2 publications.

Vertical Pull-Out Capacity of Torpedo Anchors

Abstract: In recent years, the novel concept of dynamically installed anchors like torpedo-shaped anchors has a significant development in offshore gas exploration and platform construction. Torpedo anchors are those which breach to the designated embedment depth by the kinetic energy acquired in the process of free fall and develop vertical as well as horizontal pull-out resistances. The large scale of uncertainties in pull-out capacity theoretical prediction often requires a finite element analysis. Hence, this paper investigates the vertical pull-out resistance offered by torpedo pile anchors through numerical simulation using PLAXIS. The kaolin clay soil properties are assumed, and modified cam clay (MCC) soil model is assigned throughout the entire numerical simulation. The cylindrical-shaped torpedo pile anchor was modelled with “wished in place” configuration as zero fin, blunt tip with four different aspect ratios (\(l/d\) = 5, 10, 15, 30), and each anchor is analysed under four different embedment depths to anchor height ratios (\({D/l}\) = 2, 2.5, 3, 3.5). The effects of embedment ratio and aspect ratio and their influence on the anchoring capacity were studied, and the numerical results are validated through the established empirical results. The pull-out capacities of the anchors are further studied for varying disturbed zone diameter of (1D, 2D, 3D and 4D). And hence, it is concluded that the character of the remoulded soil significantly influences the vertical pull-out resistance and the extent of remoulded soil zone due to anchor penetration is between 3D to 4D.

Analysis of Torpedo Anchors for Mooring Operations

Abstract: A novel technique of dynamically installing torpedo-shaped anchors is investigated. A vast extent of uncertainties arises in pull-out capacity estimation due to the excessive tilt of a torpedo anchor during free-fall and subsequent embedment into the seafloor. This paper will investigate the issues encountered by the torpedo anchor during the vertical drop, which ultimately reduces the pull-out resistance. The pull-out resistance study offered by torpedo anchors is investigated using a finite element tool, PLAXIS 3D. A series of pull-out tests were conducted with anchors under four different ballast conditions (20, 40, 60 and 80%) with three chosen fin configurations (without fin, 3 fins and 4 fins). The anchors are tested for various inclinations (0°, 2.5°, 5°, 7.5° and 10°) and the effect of torpedo anchor tilt on pull-out resistance is studied, and the allowable range of anchor tilt was recommended. Thus, this study provides the benefit of ideal ballast and fins arrangements.