STATICAL BEHAVIOR AND ULTIMATE BEARING CAPACITY OF STEEL-CONCRETE COMPOSITE STRUCTURE WITH GROUPED STUDS IN RAILWAY BRIDGES

Aiming at the application in railway composite bridges, substantive experimental and analytical investigations on the statical behavior and bearing capacity of composite structures with grouped studs are presents in this paper. It is found that the ultimate bearing capacity of composite structures with grouped studs reduces at most 18% compared with the normal ones. The reduction is mainly caused by the non-uniform distribution of the shear force among the grouped studs, which is in a shape of saddle from top to bottom. Ways of load transmission, stud stiffness both have influence on the non-uniform degree of shear force distribution of grouped studs. As load increasing, re-distribution of occurs till the shear force of grouped studs is distributed evenly. An effective FE simulation method was put forward and well applied. The fitted load-slip relationships of Phi 13 stud and Phi 22 stud acquired on basis of test results are well applicable for the FEA of composite structures.