A boundary element analysis on the influence of Krc and e/d on the performance of cyclically loaded single pile in clay

Abstract

The environment prevalent in oceans necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system, introducing progressive reduction in the bearing capacity associated with increased settlement of the pile foundation. To understand the effect of lateral cyclic load on axial response of single piles in soft clay, a numerical model was previously developed and validated by the author. Using the methodology, further analysis has been carried out to investigate how the variation in relative pilesoil stiffness and eccentricity effects the degradation of axial pile capacity due to the effect of lateral cyclic load. This paper presents a brief description of the methodology, analysis and interpretations of the theoretical results obtained from the further analysis and the relevant conclusions drawn there from.

The Effect of Vertical Loads and the Pile Shape on Pile Group Response under Lateral Two-Way Cyclic Loading

“…When the group piles are subjected to two-way cyclic loading and due to stress overlap, the perfect soil column enclosed by the pile group moves as a single block in one path through first half of the cyclic loading and in other path through second half of the loading cycle. Which in turn case wedge failure mode and offering less resistance for consequent cycles of loading [10]. As the spacing of piles in the group increases, the intersection of stress zones decreases, leading to improve lateral capacity of the pile group.…”

“…In the past, significant donations were prepared to the analysis of the single pile and pile groups in different kinds of soil, under lateral cyclic load, including experimental studies [3][4][5][6][7]. Also theoretical approaches [8][9][10][11][12]. In addition, below some of the latest studies of the lateral loads.…”

Piles Subjected to Torsional Cyclic Load: Numerical Analysis

“…Similarly, the long-term performance of the pile foundations subjected to axial and cyclic torsional loadings can be predicted for the known values of the cyclic loading parameters. Nevertheless, the pile foundations must be designed with adequate factor of safety against the ultimate failure and acceptable displacement at the pile head (serviceability criterion) (Basack, 2010a). For the known cyclic loading parameters and ground conditions, the factor of safety against ultimate failure can be evaluated by computing the degraded pile capacity.…”

“…Several theoretical, laboratory and field-based investigations on the pile foundations subjected to vertical and lateral cyclic loads have been conducted in the past (El Naggar et al, 1998;Cavey et al, 2000;Taciroglu et al, 2006;Basack, 2010a;Jardine and Standing, 2012). Moreover, the behavior of pile subjected to static torsion has been investigated by several researchers (e.g., Stoll, 1972;Poulos, 1975;Kong and Zhang, 2008;Misra et al, 2014;Chen et al, 2016).…”

Influence of Relative Pile-Soil Stiffness and Load Eccentricity on Single Pile Response in Sand Under Lateral Cyclic Loading

“…An extensive literature survey indicates that several approaches were suggested by various researchers to analyze the response of piles under lateral cyclic loading. Commencing from the empirical approaches (Gudehus and Hettler 1981), modified p-y curves method (Reese 1977;Allotey and El Naggar 2008) to more recent boundary element analysis (Poulos 1982;Basack 2008aBasack , 2010b) and strain wedge model (Ashour and Norris 1999), the subject has undergone advancement. Although the relevant data on the degradation for piles in clay are available, the information in case of sand is rather limited.…”