Compression strength of aged built-up column with vanished lacing bars

Abstract

Recently, Japanese aged built-up members have lost their lacing bars due to corrosion. However, the remaining strength of the built-up column with vanished lacing bars has not been clarified yet. In addition, residual stress of channel-shaped steel which consists of built-up columns has not been made sufficiently clear. The authors measured the residual stress distribution of channel-shaped steel, which was removed from an aged steel truss bridge. Moreover, the authors numerically calculated the ultimate behavior of the built-up column with vanished lacing bars using the finite element method. As a result, it is found that the residual stress magnitude of the channel-shaped steel is small compared to that of the welded member, vanishment of lacing bars does not cause a significant reduction of the compression strength and column strength curve given in Japan Specifications for Highway Bridges can be used to estimate its remaining strength conservatively.