Case Study of the Influence of Flexural Stiffness on the Developed Soil Reactions of Three Laterally Loaded Piles

This paper presents results and analyses of three full scale lateral load tests. The main objective of this study is to evaluate the influence of the pile bending stiffness in the resulting soil reactions acting around the laterally loaded pile. The case history involved three test piles installed at a well characterized sandy site and tested under similar conditions. The results presented in this paper show that the back-calculated soil reactions, at different depths and lateral deflections levels, yielded considerably different values on each test pile. This observation applied for both computational methods used which is revealing given the similar geotechnical conditions and installation procedures used for the three test piles. It is concluded that the differences in soil reactions are primarily related to the differences in flexural stiffness of the test piles (however, some variations are related to inherent soil variability within the test site). The influence of flexural stiffness in the soil reactions is explained reasonably well with the strain wedge model which allows including this important effect in the analyses. In summary, this paper presents a detailed full-scale case history hoping to shed some light on this potentially important factor of the pile flexural stiffness in the lateral soil reactions of laterally loaded piles.