New approach for predicting the load-displacement curve of axially loaded piles in sand

Abstract

A relationship to predict the load-displacement curve for axially loaded piles in sandy soil is presented by using the tri-linear softening model to describe the shaft load-displacement relationships, as well as a bi-linear model is adopted to characterize the unit end resistance-displacement reaction in the region of the pile's tip soil. Subsequently, an analytical mathematical approach to a single pile-surrounding soil interaction relation is provided as a nonlinear analysis to obtain the load-displacement curves. The mechanical response of piles under compression loading was analysed, and thus, an analytical method is developed to establish a solution for the entire compression process of the piles. A combination of the prementioned models with the pile response under compression loading was employed to establish a fully analytical approach. Furthermore, additional analytical approaches and field-tested pile loading history cases were utilized to prove the degree of exactness of the suggested method by comparing the experimental load-displacement curves with the ones founded by the proposed theoretical method in this work. The results of this study illustrate that the proposed method could be considered as an analytical mathematical technique for utilizing both the tri-linear softening model and the bi-linear elastic-plastic model for the purpose of predicting the load-displacement curves of the axially loaded pile with a 98% degree of accuracy compared to field load tests results.

Keywords

• Load- displacement curves
• Tri-linear softening model
• Bi-linear model
• Pile shaft
• Pile end resistance
• Axially loaded piles