scope:

This report describes the testing of two full-size slender-web welded plate girders for the purpose of ascertaining the acceptability of proposed design recommendations for bridge girders under repeated loading. The girders were 32 ft 6 in. and 35 ft 3 in. long with 1/4 in. thick webs, resulting in web slenderness ratios of 200 and 380. Panel aspect ratios ranged from 1.0 to 1.50. ASTM A36 material was used. These girders were subjected to repeated loading to 2.2 and 4.5 million cycles, respectively, without development of fatigue cracks and were subsequently tested under static loads to determine the adequacy of the stiffeners. It is concluded that the proposed recommendations are sufficiently conservative for ordinary bridge plate girders.