Geomechanics and Engineering A

Volume 34, Number 2, 2023, pages 209-220

DOI: 10.12989/gae.2023.34.2.209

Development of design chart for estimating penetration depth of dynamically installed Hall anchors in soft clays

Haijun Zhao, Zhaohan Zhu, Jiawei Che, Wanchun Chen, Qian Yin, Dongli Guo, Haiyang Hu and Shuang Dong

Abstract

In this study, a series of three-dimensional numerical analyses were carried out to investigate the penetration performance of a dynamically installed Hall anchor. The advanced coupled Eulerian-Lagrangian (CEL) technique was adopted to accurately simulate the large soil deformation during the vertical penetration of a Hall anchor. In total, 52 numerical analyses were conducted to investigate the relationship between anchor penetration depth and the initial kinematic energy. Moreover, a sensitivity analysis was performed to investigate the effects of soil shear strength and soil type on the penetration mechanism of a drop anchor under self-weight. There is a monotonic increase in the penetration depth with an increasing anchor weight when the topsoil of the riverbed is not subjected to erosion. On the other hand, all the computed depths significantly increase when soil erosion is taken into consideration. This is mainly due to an enhanced initial kinematic energy from an increased dropping depth. Both depths increase exponentially with the initial kinematic energy. An enhanced shear strength can potentially increase the side resistance and end-bearing pressure around a drop anchor, thus significantly reducing the downward penetration of a hall anchor. Design charts are developed to directly estimate penetration depth and associated plastic zone due to dynamically installed anchor at arbitrary soil shear strength and anchor kinematic energy.

Key Words

design chart; Hall anchor; kinematic energy; penetration mechanism; undrained shear strength

Address

Haijun Zhao, Jiawei Che, Wanchun Chen, Dongli Guo, Haiyang Hu and Shuang Dong: China Construction Eight Engineering Division Rail Transit Construction Co., L.T.D., Nanjing, 210046, China Zhaohan Zhu: School of Electrical Engineering, Southwest Jiaotong University, Chengdu, 611756, China Qian Yin: Nanjing Metro, Nanjing, 210018, China