Abstract

Mechanical properties of the soil are function of many parameters. Moisture content is one of the key factors that impact the soils’ mechanical properties. Soil-pile interaction and pile displacement in bridges can, therefore, be impacted by the moisture content. Pile displacement in Integral Abutment Bridges (IABs) due to daily and seasonal temperature variations is a problem that has been under investigation. IABs do not have joint and as a result all the load and deformation in the slab is transferred to piles. If piles are deformed beyond their yield point, plastic deformation can occur. Due to the cyclic nature of the temperature variations, this cyclic load can result in cyclic mechanical fatigue in piles and eventually failure due to this phenomenon. The objective of this study is to a new computational approach to evaluate the moisture content effect on the interaction of pile and soil and the resulting pile displacement. This computational approach uses ANSYS APDL language to repeatedly change the moisture content of the soil and adjust the properties and compute the displacement in the piles. It is shown that increasing the moisture content decreases several key parameters such as bulk density, young’s modulus, cohesion and Poisson’s ratio. The simulation results indicate higher displacements as the moisture content increases. This behavior can be explained by decreased elastic modulus. As a result, soil behaves more flexible and allows more displacement of the pile.

Keywords: Mechanical properties of the soil; Cyclic load; Moisture content; Elastic modulus; Soil-pile interaction