3D FEM Analysis on Modern Pneumatic Caisson Construction

Abstract:

Combined with the construction example, the 3D FEM simulation with a consideration of the soil disturbance during construction was proposed to predict the soil movements induced by the new pneumatic caisson method construction. The calculated soil movements were examined and verified by the field measurements. The results indicate that the maximum surface settlement exists in the caisson wall edges. During the caisson sinking progresses, the settlement increases and the influence zone on the ground surface is widened gradually. The subsurface horizontal displacements are small and vary along depths. The shallow soils tend to move towards the caisson and the maximum displacement occur to the surface, whereas the deep soils tend to move away from the caisson. Finally, the effects of several parameters which might affect the ground deformation were investigated. It can be concluded that the surface settlements close to the caisson walls are reduced significantly because of the compacted zone existence.