Research On Mechanical Behavior On Beam O With The Vertical Orifices Of Long-span Continuous Rigid Frame Bridge By Cantilever Casting

The large-span continuous rigid frame bridge constructed with the cantilever site cast construction method is widely applied at the present time.The structure and stress state of beam 0 is complex,and the vertical orifices are often made in crest slab or soleplate of beam 0 for requirement of construction and maintenance to make its stress state more complex,so it is important to make sure the quality and security of it.However, the Study of the vertical orifices of beam 0 is few and far at home and abroad,so the meaning of it is quite important. Based on Han Bin Bridge,the whole calculational model and local model were established by means of the finite element software Midas/civil and Ansys separately,and the particular local stress analysis is made with the maximum cantilever and the middle closing of span stage of bridge taken in account of,and the affection which the vertical orifices of beam 0 has for the normal stress and principal stress of crest slab,web plate and soleplate is studyed.The main works and eonclusions in this paper are presentedas follows:(1) The research situations of the concrete beam that with holes is summarized, based on the problems existed in the real engineering,the main researeh contentand method is given.(2) Studyed for the degree of affection which the vertical orifices of beam 0 has for the stress of the crest slab,web plate and soleplate, it is founded that the vertical orifices of the crest slab has significant effect on the stress of the crest slab and that of the soleplate has significant effect on the stress of the soleplate.(3) Studyed for the appropriate area of vertical orifices of the crest slab and the soleplate, it is founded the vertical orifices of beam 0 is as far as possible from the lateral centerlines of the beam section and is appropriate away from longitudinal centerline of the beam section,but not too far in order to make its stress reasonable.(4) The sides of square vertical hole on the effect of stress of beam 0 is discussesed.According to the actual bridge engineering bridge size and its load stress state, a reasonable length of vertical hole square of this bridge will be found to ensure that the beam 0 with the vertical orifices has good stress state.(5) The aspect ratio of rectangular vertical hole and the vertical hole shapes are comparative studyed,and that the aspect ratio is close to one is favorable to the stress of the beam 0 with the vertical orifices.Using circular vertical opening can ensure that the beam 0 has relatively good stress state.