Bearing capacity of prestressed and precast hollow pile to retaining wall of deep excavations

Abstract

    This study investigated the bearing capacity of prestressed and precast hollow pile to retaining wall of a 3-basement excavation in Hanoi. The retaining system was composed of prestressed and precast hollow piles and two 0.22m-thick basements. Each of piles had a cross-section of 50x52cm in semi-circle shape. The maximum bending moment that they could bear was 491 kNm. In order to adopt the piles as a permanent wall, grout should be inserted into the hollows between them to resist groundwater leakage. The studied case had a maximume excavation depth of 14.6m, at which most of subsoil was medium dense fine sand. During the course of excavation, the maximum wall displacement was small at
8.0cm. PLAXIS 3D computer software was employed to model the excavation. Resutls showed that the predicted wall displacement was compatible with the measured one and the bending moment was smaller than the wall capacity