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Vertical Pull-Out Capacity of Torpedo Anchors

  • S. Keerthi RaajEmail author
  • R. Sundaravadivelu
  • Nilanjan Saha
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 22)

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.

Keywords

Torpedo pile anchors Pull-out capacity Embedment depth PLAXIS 

Notes

Acknowledgements

The authors are thankful to acknowledge the support from the Department of Ocean Engineering and Department of Civil Engineering, Indian Institute of Technology, Madras, for authorizing the work described here to occur.

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Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Indian Institute of TechnologyChennaiIndia

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