On the Initial Imperfections and Their Relations to the Strength of Webplates of Actual Steel Bridges

Abstract

This study is mainly concerned with statistical investigations on the actual initial imperfections and their relations to the load carrying capacities of the webplates of steel bridges. The basic data to be used throughout the study have been collected by the Initial Deflection Measurement Committee, IDMC, of the Society of Steel Construction of Japan, abbreviated as JSSC. In order to show what types of webplate systems are covered throughout the study, various statistical information on the mechanical and geometric parameters is firstly presented, and then, various kinds of the initial imperfections existing in the actual steel bridges are subjected to statistical considerations. Through the statistical analyses, the probabilities of exceedance of various imperfections are evaluated. From these fractile values, some comments on the regulations of the initial imperfections by the current design codes are drawn.