Abstract: The large deep excavation of the stress and strain in pile groups was analyzed with three dimensional finite elements analyses. The stress strain characteristics in the pile group are significantly different from those of in the single pile. For pile groups under the bottom of the excavation, the axial stress in the pile increases in the depth of the excavation. The location of the maximum force in the pile changes from the top to the middle part of the pile. Whereas, in the single pile (without pile cap), the maximum axial force is located at the lower portion of the pile. At the same excavation depth, the smaller axial force could be found in piles near the slurry wall; large axial force can be found in piles that are close to the center of the excavation with a larger pile deformation and mobilized side resistance in piles. Due to the lateral deformation of the supporting structures, piles that are closed to the supporting structures have large bending moments. As a result, these piles have large deformation in the upper portion of the pile.

Key words: Deep Excavations, Pile Groups, Finite Element Methods