| 摘要 |
PURPOSE:To avoid dimensional unevenness of the legs of a jack-up rig by a method in which a horizontal brace is assembled in a triangular plane form in such a way that three top points are formed by varying the distance from the center according to the welding contraction and the braces are built into a large leg unit block by leaving the braces at the ends of the leg unit block unwelded. CONSTITUTION:A plane brace 6' is assembled from three horizontal braces 7' and inner braces 8', where the distance B from the center O of the brace 6' to the top F is made large than the distance A to other two tops P and S. Then, two cords 4' are welded to the lower tops P and S of the brace 6 on an assembly board (not illustrated), unit block 1 is assembled by using plural braces 6', and each top of the brace 3 is temporarily welded. Then, next block II is assembled, the brace 3 are welded to the braces 4 and 5 by leaving the brace 6 temporarily welded, and next block III is assembled. Thereafter, the same procedure is repeated. |
