Discussion on ultimate load carrying capacity of concrete filled steel columns with initial stress

The present situation of the research and the mainly result are summarized for the capacity of concrete filled steel tube (CFST) columns with initial stress. Four methods for calculating the capacity of CFST columns with initial stress by far are concluded. Basic characteristics and factors of each method are expatiated,and calculating results by each one and testing results are compared. Results indicate that the fourth method can be more preferable used than the sencond method as well as the third method in engineering application,the first method is partly nisecurity and not suitable to be applied.