Pullout capacity of plate anchor in unsaturated frictional soil using particle size-based soil water retention curve

¹ Research Scholar, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
² Associate Professor, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India

^* Corresponding author: bakna20@iitk.ac.in

Abstract

The soil water retention curve (SWRC) plays a crucial role in evaluating the stability of anchors in unsaturated frictional soil. However, determining SWRC parameters experimentally is time-consuming and costly. There has been no study done to evaluate the stability of plate anchors in frictional soil using SWRC parameter predicted based on easily determinable soil property. This study incorporates a correlation between grain size (D60) and the Fredlund and Xing SWRC parameters to overcome these challenges. The stability of a plate anchor is then analysed using finite element lower-bound limit analysis, integrating suction stress into a modified Mohr-Coulomb yield criterion for unsaturated frictional soil. Various factors have been considered, including embedment depth, anchor width, water table position, saturated unit weight and internal friction angle. Results indicate that ultimate uplift load consistently increases with a rising water table for D60 = 0.1 mm. However, for other grain sizes, the failure load trend varies depending on embedment depth and water table position. Notably, variations in uplift load for different D60 values align with the corresponding suction stress trends.