Nonlinear deformations of laterally loaded piles embedded in stiff clay located below the water table: Sensitivity analysis.

Sensitivity analysis is one of the methods predicting how sensitive a soil-pile interactive system will behave under a lateral loading, whether a horizontal force or a bending moment, due to the changes of the design variables. For a civil engineer, it is important to know what is the deformation at the top of the pile foundation to be considered for the upper structure. Therefore, the sensitivity analysis in this thesis focuses on the changes of the displacement and the angle of flexural rotation at the top of the pile due to the changes of the design variables which are the stiffness of the pile (EI), the cohesion of the soil (c), the modulus of subgrade reaction (k), the effective unit weight (gamma'), the strain at which 50% soil strength is mobilized (epsilon50 ) and the width of the pile (b). Sensitivity analysis of laterally loaded single piles and pile groups embedded in stiff clay located below the water table was conducted by means of an adjoint method. The pile is modelled as a one dimensional beam element. The surrounding stiff clay is modelled by means of a p-y relationship proposed by Reese, Cox, and Koop developed in 1975. The sensitivity analysis results consist of the distributions of the sensitivity integrands along the pile depth and the assessment of the sensitivity integrands for a collection of single isolated piles as well as pile groups that are subjected to horizontal forces as well as bending moments in a discrete manner. In Chapter VI of this thesis, numerical investigations were carried out for a better explanation. The soil-pile parameters affecting the structural response were determined and ranked from the most to the least effect on the state variables (the pile deformations at top).* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. ...