Three-dimensional numerical analysis of deformation and mechanical behavior of deep excavations adjacent to river

A three-dimensional numerical simulation based on FLAC3D is carried out to investigate the deformation and mechanical behavior of a deep excavation project adjacent to Huangpu River in Shanghai soft soil deposits, in which the impacts of zoned excavation, installation of partition wall, inside spaced strip and peripheral ground reclamation, and variation of outside tide level are considered and the comparison with in-situ monitoring data is conducted. The predicted lateral displacement of the retaining wall agrees well with the monitored value, consequently, the reliability of the numerical model is verified. The study shows that it is advantageous to the global stability of the retaining and propping structures with symmetric loading condition under the mean tidal level. The effect of the partition wall on deformation control of the retaining wall is not distinct; nevertheless, the influence of variation of tidal level on the lateral displacement of the top of the retaining wall is conspicuous, resulting in change of compression and tension state of the first level strut. Therefore, cast-in-place reinforced concrete beam is recommended for the first level strut to ensure effective connection between the strut and the retaining wall.