Numerical Analysis of Inclined Granular Pile Anchor Subjected to Uplift Forces in Expansive Soil using Abaqus

Abstract

Granular pile anchor is a new technique that is commonly used to improve the pullout resistance of expansive soil like soft clay, loose sand, and black cotton soil. Using the Abaqus software, this work presents a numerical investigation to estimate the pullout capacity of granular pile anchor in soft clay. By applying a specified displacement of 10% of D (pile diameter) on the granular pile anchor, the effects of length, diameter, angle of inclination (α), and number of GPA at varying spacing values on uplift capacity is examined. Additionally, L/D ratios of both individual and group piles are examined using various variables. The study uses expansive soil and GPA of unit weight 17 kN/m3 and 22 kN/m3, poisson’s ratio of 0.4 and 0.3, modulus of elasticity 4 MPa, and 11 MPa, respectively, for the estimation of uplift capacity. The cohesion value for the expansive clay is 25 kPa, and the angle of shearing resistance for GPA is 36˚. According to the numerical study, both for a single pile and for piles placed in a group, with increases in pile length and diameter, the granular pile anchor's pull-out capability improves. For a pile placed in group the value of the pull-out capacity shows optimum result when spacing (S) is 2.5D. Additionally, the uplift capacity of the granular pile anchor increases with an increase in angle inclination (α) from 0˚ to 10˚, and then decreases from 10˚ to 15˚. The efficiency of GPA is examined, which assists in the choice of the different granular pile anchor parameters.