Application And Analysis Of Actual Project With Buckling Restrained Braces

Buckling restrained brace (BRB) improved by ordinary steel braces regarded as a new member provides the comparable stiffness and strength of an ordinary steel brace without the problem of compression buckling. BRB yields in tension and compression. In the case of uncommon on seismic action, it exhibits stable and predictable hysteretic behavior and provides significant energy dissipation capacity, being an attractive alternative to protect the frames. There has been a complete set of theory system mainly to BRB in the new construction by predecessors’test analysis and research, but it is still not mature in the application of the adding-layer reconstruction project. According to the author’s participating in an actual project along with the analysis and the research, the main work in the essay is as following:Firstly, it adapts light steel adding-layer technology in the actual project in this article. According to the pure frame structure’s inter-storey stiffness and nominal stiffness ratio, we install the BRB at both ends of the building and propose two kinds of setting plans so as to solve the problem of appearing of the stiffness mutation.Secondly, through the modal analysis and comparative analysis of the results, we may draw the conclusion that two setting plans can achieve the desired effect, and that the torsion period can also be controlled very well in the whole structure with BRBs, which makes the period ratio diminish and the structure become safer.Thirdly, through the vibration mode decomposition response spectrum method analysis and comparative analysis of the results, we may draw the conclusion that the lateral stiffness along the vertical distribution is even in the whole structure with BRBs, and that the elastic inter-storey displacement angle can meet the requirement of the current norm. According to the different layouts, the floor total shears also have the corresponding changes compared with the whole structure without BRBs, which further shows that the BRB has the effect of shock absorption.Finally, the whole structure with BRBs belongs to the shock absorption and energy dissipation structure system and it is necessary that the time history analysis in the case of uncommon seismic action is performed for the structure. We find only one of the two programs can meet the demand through checking the plastic inter-storey displacement angles, which illustrates that the reasonable setting can weaken the seismic action on the whole structure’s adverse effect. Through analyzing and researching BRBs’filling degree of hysteretic curve in the case of uncommon seismic action, we can draw the conclusion that the reasonable one’s hysteretic curve is full, so the energy dissipation effect is obvious, which illustrates that setting the BRB in adding-layer reconstruction project is a very effective shock absorption and energy dissipation means.