Abstract: H+Hat combined steel sheet pile has a broad prospect of application due to its simple structure, big bending stiffness, repeated usage and cost effectiveness. However, it has not been applied in China yet and lack of verification. In view of this we carried out theoretical calculation, indoor experiment, in situ test and numerical simulation to research the sectional flexural performance, lock tensile performance and lock waterproof performance of H+Hat combined steel sheet pile. Results reveal that the sectional flexural modulus of H+Hat combined steel sheet pile is larger than that of ordinary steel sheet pile with good flexural performance; the allowable lock tensile strength is far greater than that in actual operation; and the lock waterproof performance is not worse than that of ordinary steel sheet pile. The research could be a basis for the popularization and application of H+Hat combined steel sheet pile in foundation pit, piers, docks, cofferdam, and bank supporting structures.

Key words: H+Hat combined steel sheet pile, structural behavior, flexural strength, waterproof performance, in-situ test, numerical simulation