The strength of empty steel pipe should be checked according to the construction stage load for the laminated column constructed in different period,and the maximum compressive stress value is unsuitable more than .6fa(fa is steel pipe steel the compressive strength of the design value).Composite than can be through the test are determined,usualy desirable-.6 composite ratio m=N /N M-composite ratio of composite column constructed in different period. N-Composite column axis pressure design value. compression design valueacton the CFST before the outer RCeasted If Composite ratio is too large,the requirements of the composite bearing capacity cannot be satisfied:If too small,the characteristics of composite column cannot be given full play. 7 BEAM COLUMN JOINTS Table 5 beam-column joints types of CFST and composite column types CFST column composite column I outer strengthen rings(smaller 1.only one steel beam,see column diameter） figure 5 Steel beam-column connection 2.inner strengthen rings (larger 2.all the steel beams,see column diameter) Transfer shear:I ring bracket 2.Bearing pin 2.Steel plate fin transformation Transfer bending moment: 3.Steel pipe reinforced RC beam-column connection 1.Well type double beam transformation (Construction in the 2.ring be m 3.wear muscle ame period) single-girder 4.various width beam Note:the shear transfer and moment transfer forms are introduced respectively in the CFST structure,and Suitable forms combination is need in practice. 7.1 CFST structure 7.1.I Steel beam-column connection:The strength of empty steel pipe should be checked according to the construction stage load for the laminated column constructed in different period, and the maximum compressive stress value is unsuitable more than 0.6fa(fa is steel pipe steel the compressive strength of the design value). Composite than can be through the test are determined, usually desirable 0.3-0.6. composite ratio m  Ni / N M—composite ratio of composite column constructed in different period. N—Composite column axis pressure design value. Ni—axis compression design value act on the CFST before the outer RC casted If Composite ratio is too large, the requirements of the composite bearing capacity cannot be satisfied; If too small, the characteristics of composite column cannot be given full play. 7 BEAM COLUMN JOINTS Table 5 beam-column joints types of CFST and composite column types CFST column composite column Steel beam-column connection 1 outer strengthen rings (smaller column diameter) 2. inner strengthen rings (larger column diameter) 1. only one steel beam, see figure 5 2. all the steel beams, see figure 6 RC beam-column connection Transfer shear: 1 ring bracket 2. Bearing pin 1. Steel pipe breakthrough type 2. Steel plate fin transformation 3. Steel pipe reinforced transformation (Construction in the same period) Transfer bending moment: 1. Well type double beam 2. ring beam 3. wear muscle single-girder 4. various width beam Note: the shear transfer and moment transfer forms are introduced respectively in the CFST structure, and Suitable forms combination is need in practice. 7.1 CFST structure 7.1.1 Steel beam-column connection：