关键词: 扩大截面法, 加固柱, 二次受力, 三向受力, 数值计算

Abstract: Axial compression short colunm with round cross-section is reinforced by enlarging cross-section method, for it is short of bearing capacity. In order to study the destruction limits and the bearing capability of normal cross-section of rein- forced column, the radical stress of the reinforeed column is obtained through the iterative numerical solution, according to the force balance of concrete at the junction of old concrete and new concrete. The vertical compressive strength of old concrete is calculated by tri-axial stress ; the compressive strength of new concrete is calculated by pulling in ring and pressing in longitude. When pulling-strain of the new enclosed concrete reaches the strain limits, the new concrete rips; meanwhile, the strengthened column reaches the destruction limits.

Key words: enlarging cross-section method , strengthened column , secondary loading , tri-axial stress , numerical calculation ;