Energy-Based Analysis of Laterally Loaded Caissons with Large Diameters under Small-Strain Conditions

Abstract

To better predict the response of laterally loaded caissons and the displacement distribution around the foundations, three different beam theories [Timoshenko beam theory with vertical (z) displacement in soil, Timoshenko beam theory without z displacement, and rigid beam theory with z displacement] were compared in the energy-based variationally method, and two caissons from real projects under the initial loading state were studied. The results from the three methods are compared with measured data from field tests and three-dimensional differential analysis. From the study, the method of the Timoshenko beam theory that considers z displacement in the soil domain produces the most accurate results. The rigid beam theory produced the worst prediction when estimating caisson displacement, rotation, and bending moment. Therefore, for the structure–soil interaction of a laterally loaded caisson, the suggested structure is a Timoshenko beam, and the vertical soil movement around the beam should be considered.