Abstract
In the Landmark Tower, a super high-rise building possessing 70 levels above ground and a height of 296m and completed in 1993 in Minato Mirai area of Yokohama, low yield ratio steel of 60k (570N/mm2) grade for building structures is used for the steel columns which are subjected to a large axial force. On the basis of the results obtained through the experimental study of 60k grade thick steel plate, a method for heat control in welding process was established.
