Design Guidelines for Laterally Loaded Large Diameter Piles

Abstract

Coastal soil formation covers many places all over the world in which the upper soil layer is soft to very soft clay extended to great depths followed by a stiff layer such as dense to very dense sand. Due to the low shear strength, the high compressibility of the upper soft clay and the vast advances in construction of tall and heavy buildings, large diameter piles are utilized to safely transfer large vertical and/or lateral loads to the bearing stratum. The main objective of this research is to analysis and design of large diameter piles especially piles with diameters larger than 1.2 m as most of the design criteria are controlled by relatively smaller diameters usually ranging between 0.6 m to 1.2 m. Hence, a parametric study is performed using Finite Element Method to study the behavior of large diameter piles under vertical and lateral loads. This numerical modeling aims to assess the actual lateral load capacities for large diameter pile then recommend guidelines for designing such piles in such weak soil formation. Results show that piles with diameters less than or equal to 1.6 m should safely carry a lateral load less than 100 kN. While piles with diameters larger than 1.6 m can safely carry lateral loads up to 200 kN to satisfy the serviceability conditions. The study also showed that, increasing the pile embedment length in the end bearing layer has no significant effect on the lateral load capacity of large diameter piles.