Stress distribution of embedded caisson foundation under lateral load based on the continuum approach

Abstract

An analytical method is proposed to characterize the stress distribution of the soil around a caisson foundation under lateral load in an elastic half-space. A series of model-scale tests is performed to delineate the characteristics of lateral resistance stress along the foundation periphery. Accordingly, the mathematical expression of circumferential resistance stress is established based on the elastic-beam theory. Thereafter, the stress increment in the surrounding soil is derived by numerically integrating the Mindlin’s stress solution. The analytical solution for the stress variation in different directions can be solved by a numerical calculation program, the effectiveness of which is further evaluated by comparing with the experimental results. It is found that the stress increment of the soil around the caisson foundation decreases exponentially with the increase of the distance from the foundation side. The vertical additional stress is approximately saddle-shaped and anti-symmetric with respect to the x-axis and the y-axis of the foundation. A bridge project with caisson foundation is further analyzed using the proposed method to demonstrate the influence of caisson foundation geometry, including the embedment and the diameter, on the additional stress distribution.