The Experiments And Analyses Of The Performance Of Rc Pile Caps-Steel Column Base Combinational Part

The National Stadium is the main stadium of Beijing 2008 Olympic Games. The large span structure of the'Bird-nest'will become one of the important landmark constructions in Beijing. Because geometry size of steel column base of National Stadium are big, whose stress state is complex, and similar experiments were few in the past at home and abroad. The studies of the anchorage performances of steel column bases under uniaxial reversed loads are carried out through tests and theory. The idiographic contents are listed as follows:1) Through the tests of the anchorage performances of steel column bases of 1/5 scale under uniaxial reversed loads, the tested ultimate loads, ductility, stiffness and reasonable modes of reinforcement design of two specimens are presented in this thesis. One specimen is fitted up with anti-punching shear bars and the other is not.2) The elastic-plastic analyses of two experimental elements under uniaxial reversed loads are made by ANSYS (a finite element analysis program) and the results of analysis match the experimental results very well.3) A study is carried out to understand the changing rule of ultimate load and stiffness with the different reinforcement ratio of anti-punching shear bar. The increasing speed of the ultimate load is slower than that of the reinforcement ratio is indicated.4) A simplified mechanic model for calculated ultimate load is proposed. The calculated results correlate well with the results of experiment.5) Some design suggestions for similar structures.The cracking load, yield load, marked cracking load and ultimate load of the specimen with anti-punching shear bar was higher than that of the corresponding specimen. The design of a practical project is based on the study of this thesis.