PURPOSE: To shorten a pile driving time when hammer-driving the pile into the ground, and also to sharply reduce buckling being provided at the end part of a joint and coming off of the joint, by providing a throttled part at the end part of a tubular joint welded at a steel pipe sheet pile.

CONSTITUTION: Two tubular joints 2, 2 are welded in the axial direction at both ends positioned in the direction of a diameter of a sheet pile proper A made of steel pipes. An engaging slit 3 is cut in the axial direction across the joint 2, and a throttled part 4 is provided at the end part. The steel pipe sheet pile A is hammer- driven in the ground, and the subsequent sheet pile is hammer-driven so that the slit 3 of the precedent sheet pile engages with the slit 3 of the subsequent one, and thus, repeating of the aforesaid processes leads to construction of a continuous wall. At this time less sand comes into the joint 2 since the throttled part 4 is provided at the end of the joint 2 and as a result the end becomes smaller. And thus, a small friction resistance between an internal surface of the joint 2 and the sand enables a rapid hammer-driving of the sheet piles and causes the joint to be free from coming-off the sheet pile A which results from buckling yield at the joint.