In order to study the structural robustness of fastener steel tube formwork support for independent beam

a target-oriented stable critical bearing capacity based on the controlled deformation is proposed in combination with the internal force and deformation features of structure under the condition of instability

and an existing quantitative index for evaluation of structural robustness is improved.Through the calculation and the comparison of 4kinds of design model for formwork support

the effects of the transverse spacing of upright tube at epitaxial both sides of beam and the strengthened layer of horizontal tube on the structural robustness are analyzed.Result indicates that the component vulnerability coefficient of upright tube at loading zone is significantly greater than that at non loading zone

and its member importance coefficient is slightly less than that at non loading zone.Decreasing the transverse spacing of upright tube at epitaxial both sides of beam can effectively improve the structural robustness.Setting the strengthened layer of horizontal tube could improve the stable bearing capacity of structure in a certain extent

but the structural robustness has been reduced.