Analysis of bearing and influence complications of concrete filled double skin(SHS inner and SHS outer) steel tubular columns

Based on unified strength theory,the load capacities of the concrete filled double skin(SHS inner and SHS outer)steel tubular columns under axial compression are investigate.By introducing the reduction factor of concrete strength and the equivalent restriction reduction factor,concrete filled double skin(SHS inner and SHS outer) steel tubular columns is turned to concrete filled double skin(CHS inner and CHS outer) steel tubular columns.Based on unified strength theory solutions of thick tube,combined with concrete filled skin tube unified theory.Deduce the calculation formula of bearing capacity of concrete filled double skin steel tubular columns and analyse the influence complication.Compared with the solution obtained in this paper and the experimental results,the good agreement can be found.The results indicate unified strength theory has the good applicability and the solution has an important practical value.