Cofferdam structure with cement mixing piles combined with steel sheet piles and construction method

The invention provides a cofferdam structure combining cement-soil mixing piles with steel sheet piles and a construction method. The cofferdam structure comprises a plurality of drill holes formed in an island, the cement-soil mixing piles are poured in the drill holes, the steel sheet piles are inserted in the cement-soil mixing piles, the multiple steel sheet piles are connected to form a closed space, and a supporting system used for stabilizing is arranged in the closed space; the drill holes comprise a plurality of first hole sites and second hole sites which are arranged at intervals, and overlapping areas are arranged between the first hole sites and the second hole sites. The structure is compact, the problem that pile sinking is difficult during hard geological construction can be solved, the overall construction efficiency is greatly improved, the construction safety risk is reduced, water and soil are effectively prevented in the construction process, and the construction quality is better. 本发明提供一