Analysis on Deformation Monitoring Results of Retaining Structure in Subway Extra-deep Foundation Pit

Abstract:

Based on the deformation monitoring results of the extra deep foundation pit at Yanggaozhong Road station of Shanghai subway line 18, the deformation regularity of the deep foundation pit retaining structure is discussed from the aspects of the horizontal & vertical displacements of the retaining structure and the vertical displacement of the column pile. The analysis shows that with the layered excavation of the foundation pit, the horizontal displacement curve of the retaining structure shows a “big belly” shape, the maximum displacement point constantly moving downward, and finally being stable at about (093～107) times the excavation depth; the maximum horizontal deformation is about 330‰ of the excavation depth; the everage maximum bulging deformation is about 052‰ of the excavation depth; the column is bulged with the displacement about 091‰ of the excavation depth. All the deformation is basically consistent with the deformation trend of monitoring data in peripheral pipelines, so the above-mentioned regularities are expected to be reference for the design and construction of similar projects in the future.

Key words:subway station; extra-deep foundation pit; retaining structure; deformation monitoring