Study on the Load Transfer Routine in Truss Bridges with Integral Decks

There are two routes of load transfer in the integral deck with multi-transversal beams.Part of the load transferred to bottom chord joints is through longitudinal beams,longitudinal ribbed stiffeners,deck and transversal beams at chord joints;and the other is through transversal beams in the panel,deck and bottom chord elements.The former causes transversal beams at chord joints to bend and the latter makes bottom chord elements bend.In this paper,the structure calculation and the experimental research were carried out to investigate the load transfer in the type of floor system.The results indicate that the main influence factors of the load transfer ratio,which is namely the ratio of the load distributed by a route to the total load in a panel,are the ratio α of the vertical stiffness of bottom chord elements to that of the floor system(including the longitudinal beams,longitudinal ribbed stiffeners and deck) and the ratio β of the vertical stiffness of a transversal beam in the panel to that of a transversal beam at the chord joint;load transfer ratio R_2 of the second route increases gradually with the increment of α; R_2 increases quickly when α is less than 8.3 and varies small when α is greater than 25;R_2 also becomes greater and the increasing speed reduces slightly with the increment of β;the load transfer ratios in different panels change small and the experimental results achieve good agreement with the theoretical results.