Lateral Dynamic Response of Helical Pile in Viscoelastic Foundation Considering Shear Deformation

Abstract

Helical piles are a new type of pile that has good application prospects, and researchers have carried out an in-depth investigation into their vertical uplift and compressive bearing capacity. However, there is relatively little research on the dynamic bearing characteristics of helical piles. Therefore, the lateral vibration of a helical pile embedded in the viscoelastic foundation is systematically studied in this article. Utilizing the equivalent stiffness method to transform a helical pile into a cylindrical pile of special diameter, the lateral vibration model of the helical pile considering shear deformation is established based on the Winkler foundation model and the Timoshenko beam theory. The analytical solutions for the lateral dynamic displacement, bending moment, and shear force of the helical pile are strictly derived, and the rationality of the present solutions is also verified by comparing them with existing solutions. Based on the present solutions, a parametric study is carried out to investigate the influence of the pile and soil properties on the lateral dynamic response of the helical pile. It is found that the load excitation frequency and pile–soil stiffness ratio have a significant influence on the lateral dynamic displacement, bending moment, and shear force of the helical pile with space and time response.

Model Test Study on the Vertical Uplift Bearing Characteristics of Soil Continuous Solidified Pile Group Foundations

“…Khatri et al [16] proposed a formula for the ultimate uplift capacity of piles in cohesive soil where the undrained cohesion linearly increases with depth. Based on the Winkler foundation model and Timoshenko beam theory, Yang et al [17] established a lateral vibration model of screw piles considering shear deformation and derived analytical solutions for the lateral dynamic displacement, bending moment, and shear force. Patra and Pise [18] proposed a simplified method to predict the ultimate uplift capacity of pile groups, taking into account factors such as the buried length-to-diameter ratio of the group pile and the pile spacing.…”

Field Experimental Study on the Uplift and Lateral Capacity of Deep Helical Anchors and Grouped Helical Anchors in Clays

“…The results showed that spacing the anchors at approximately three times the diameter of the largest helix did not lead to a significant decrease in the uplift capacity of each individual anchor [41]. The characteristics of grouped helical anchors under lateral static [21,35,[42][43][44][45] and dynamic loads [46][47][48][49][50] have been studied. In a study conducted by Venkatesan Vignesh, the uplift and lateral behavior of group piles installed in soft clay soil was studied using a finite element and 1 g model experiment.…”