Theoretical And Experimental Study On The Shear Lag Effect Of Box Beam With Corrugated Steel Webs

The composite box girder with corrugated steel webs is a new structure with corrugated steel webs instead of concrete webs. The steel webs bear the most of the shear force, the top and bottom concrete slabs bear the moment of flexure chiefly. It makes use of the material characteristics of concrete and corrugated steel webs that can reduce the workload of bridge construction effectively. On the foundation for referring related documents and analysis of builded bridges home and abroad, through theoretical analysis, experimental study and finite element analysis, this dissertation makes systematical research on the shear lag effect of box-girder with corrugated steel webs.On the basis of shear lag effect theory for box-girder, and combined with its structural property, the energy-variational Theory and the bar simulation method are adopted for analyzing its shear lag effect and calculation methods under the concentrated load and uniformly distributed load. A presumption, named"quasi plane", is introduced when shear lag effect is considered.The laboratory experiments of two model beams indicate that the"quasi plane"presumption is well approximate. Experiment data prove the longitudinal stress of concrete slab obtained by adoption of the energy-variational theory and the bar simulation method should not bring a bigger error margin. Further more, the results of finite element analysis are well coincide with those by energy-variational theory, the bar simulation method and the model test. Therefore, the method of this paper has practical significance and may be selected to use for designer.By finite element analysis, on one side, the geometry parameters and the boundary conditions of the structures are analyzed, the main geometry parameters of all are confirmed on, on the other side, the type of the load, the lateral diaphragm space, the external prestress and the type of beam's webs are analyzed.