Lock opening steel pipe pile cofferdam suitable for deep water shallow covering layer and construction method of lock opening steel pipe pile cofferdam

The invention discloses a fore shaft steel pipe pile cofferdam suitable for a deep water shallow covering layer and a construction method of the fore shaft steel pipe pile cofferdam. The construction method of the fore shaft steel pipe pile cofferdam comprises the steps of fore shaft steel pipe pile driving, hole guiding construction, reaming construction, grouting pipe grouting and steel pipe pile bottom sealing. The fore shaft steel pipe pile cofferdam comprises a fore shaft steel pipe pile enclosing structure, bottom sealing concrete, girders and diagonal bracing steel pipes. The mode that the I-shaped steel is inserted into the C-shaped fore shaft pipe to form the active fore shaft steel pipe pile is adopted, and the bottom is installed in a hole guiding and reaming mode, so that the problem that the fore shaft is torn when encountering a hard rock stratum in the steel pipe pile driving process due to the fact that the rigidity and deformation of the fore shaft and the steel pipe pile are not coordinated