Practical Retrofitting Case Study On Composite Beam By Adding H-type Steel Member Under The Concrete Beam

The composite beam by adding H-type steel under the concrete beam, which is studied in this paper, is a kind of composite beam applied in retrofitting engineer. The composite beam is formed by adding H-type steel beam under concrete beam by shear connection such as structural glue and anchor bolts. The design method for normal steel-concrete composite beam can be applied for this kind composite beam. As the H-type steel beam and the shear connection are post added and the actual condition is restricted for adding anchor bolts with enough numbers designed according to the current code, other kinds of shear connection for H type steel member and concrete beam, such as structural glue must be considered.A practical case was studied in this paper. The normal design methods are used here firstly. The number of bolts designed by the existing code is so large. It is impossible to apply enough bolts in the practical situation. Hence both the structural glue and the anchor bolts should be used in this project. This paper made some research works on the composite beam, listed as following:1. Referring to the theoretical results in the slipping calculation of shear connection in the related references, the stiffness and deformation of composite beam and etc, this paper made deduction on the slipping and the normal stress in the elastic stage. The finite element method was used here for verification.2. This paper made some recommendation for anchor bolt distribution, based on the comparative analyze of bolt's slipping and the normal stress by finite element method for different parameters.3. This paper made the finite element analysis using the model which was the same as the real composite beam of this engineer project. Through the calculation of whole numerical process with the maximum load near to the ultimate bearing capacity, the design method for the composite beam design is verified here for the shear connection by both anchor bolts and structural glue.4. Some suggestion such as the choice for the steel beam height and the shear connection was given in this paper for designing this kind of composite beam in similar engineering.