Abstract:The land section of dushu Lake Second Passage project adopts open-cut construction method, and the water section adopts open-built cofferdam construction method. The determination of the overall road scheme is mainly affected by planning, navigation assessment and flood assessment. For the land-based tunnel foundation pit adjacent to the surrounding sensitive building section, the stiffer ground wall supporting form is mainly adopted, at the bottom of the foundation pit, the passive zone is strengthened, and the isolation measures of MJS and bored pile are adopted. In order to reduce the hidden danger of water leakage in the water tunnel deformation joint, the scheme of pile foundation + pillow beam is adopted in the deformation joint, by reducing differential settlement to ensure the performance of the water stop belt. For the water section, the cofferdam with double rows of steel pipe piles is adopted, and the zoning construction scheme is adopted according to the conclusions of navigation and flood assessment, It meets the normal passage and flood control requirements of the waterway during construction and takes corresponding measures for the overall stability of the structure and anti-seepage stability of the transverse cofferdam, Finally, the mutual influence of foundation pit and cofferdam is analyzed to ensure their safety. Through engineering practice, the above key technologies are reasonable and feasible, and provide reference experience for similar projects.
