PROBLEM TO BE SOLVED: To improve workability, for example, of a construction method for a steel sheet pile-combined spread foundation.
SOLUTION: A plurality of U-shaped steel sheet piles 51, to which perforated steel plates 6 are prewelded, are driven into ground 2 in order, so as to form a rectangular-cross-section steel sheet pile structure 5. An almost rectangular anchor reinforcement 8 is latched to a hole of the steel plate 6, and horizontally held in the state of being directed to this side. The cast-in-place concrete is placed to form a footing 3. Thus, the anchor reinforcement 8 does not have to be stud-welded to the steel sheet pile 51, and the risk of weld dripping is eliminated. This makes the use of the thick anchor reinforcement 8 reduce the required number of the anchor reinforcements 8. Workability particularly for the steel sheet pile 51 on the back side is enhanced. The anchor reinforcement 8 can easily reach an inside with respect to a footing reinforcement.