Finite element model was established for restrained partially encased concrete（PEC）columns subjected to 4-side heating under ISO-834 standard fire

which was verified by fire resistance experimental data of PEC columns.Based on the verified model

the influence of parameters including axial restraint ratio

load ratio

load eccentricity ratio

sectional dimension and moment distribution modes was analyzed on fire behavior of restrained PEC columns.Results show that:the axial deformation and the axial force variation coefficient increase gradually at initial stage

then reduce gently

and finally decrease quickly.The influences of sectional dimension and moment distribution mode on the axial deformation and axial force variation coefficient are limited

also as the influence of load eccentricity ratio on the axial deformation.The axial deformation increases with the axial restraint ratio and load ratio decrease

while the peak value of axial force variation coefficient increases with the decrease of the load ratio or the increase of the axial restraint ratio and load eccentricity ratio.Fire resistance is the shortest under the uniform bending moment distribution mode

and fire resistance of PEC column has slight difference between triangular bending moment distribution mode and reverse bending moment distribution mode.