Underwater support concrete structure construction method

A construction method of a foundation for a underwater support structure, comprising:

• (a) installing a pile (200) having a head part (210), in which a catching groove (220) is formed, in a sea floor;
• (b) fabricating the foundation (100) for the underwater support structure, in which a buried guide tube (110) is formed to protrude downwardly from a lower surface of the foundation (100), and settling the foundation (100) for the underwater support structure on the sea floor, such that the head part of the pile (200) is inserted into the guide tube (110);
• (c) anchoring the pile (200) into the guide tube (110) and the guide tube (110) penetrates the sea floor;
• using an elastically protruding settlement device (300) formed in the guide tube (110);
• and
• (d) injecting a filler (400) into the guide tube and onto the sea floor under the foundation for the underwater support structure through an injection port (130) configured to extend from a surface of the foundation (100) for the underwater support structure into the guide tube,
• wherein the elastically protruding settlement device (300) comprises an elastic spring (320) installed in a horizontal hole (140) which is previously formed in the foundation (100) for the underwater support structure;
• and a stopper (310) set so that a surface of one side end thereof is in contact with the elastic spring (320) and a pin-jointed roller (330) is formed at a surface of the other side end thereof, which protrudes into the guide tube.