Crack Propagation of Prestressed Concrete Multi Girder Bridge Subjected to Vertical Symmetric Loads

摘要

The prestressed concrete multi girder bridge is composed of main beams and diaphgrams. Cracks are inevitably existing in the structure. The regularities of crack propagation of the prestressed concrete multi girder bridge subjected to vertical symmetric loads are studied based on nonlinear finite element theories. From shell element degraded from continuous body, steel and concrete are modeled by layered shell element. With some available criteria, the material nonlinear properties of concrete and steel are considered. Then the procession of cracking, yielding and failure of prestressed concrete multi girder bridge is imitated and the analytical three-dimensional procedure is compiled. For a certain prestressed concrete multi girder bridge when subjected to two typical vertical symmetric loads, the computational results show that the cracks emerging in the diaphgrams are earlier than those in the main beams. The crack propagation pictures of important load rands are listed in order to prove the significant regularity. For practical engineerings, emphases should be also put on the cracks in the diaphgrams.