The statements in the JGJ 3-2010 'Technical specification for concrete structures of tall buildings' about the overall stability of high-rise buildings were discussed. The applicability of the overall stability judgment and the limit value of stiffness-weight ratio were analyzed, and the insufficiencies of the relevant regulations when applied to complex connected high-rise structures were clarified. Based on the principle of Euler's critical instability, the stiffness-weight ratio limit value applicable to rigid-connected-tower building were re-derived. This limit is mainly affected by the relative stiffness of the connector and the tower. Through four case studies, it is shown that the approach in the technical specification tends to be conservative, which would amplify the adverse effects of the second-order effects. For heteromorphic connected structures with more complicated connections, the stability judgment method using stiffness-weight ratio limit will not be suitable, in which case nonlinear stability analysis considering second-order effects is recommended. Similar to the design approaches used for spatial structures, the overall stability of the high-rise buildings could be evaluated through eigenvalue buckling analysis, direct static stability analysis considering geometric nonlinearity, and ultimate stability failure analysis considering material damage. Finally, taking a complex three-tower connected high-rise structure as an example, stability analysis was performed according to the above method. The results show that the stability load factor of the structure is greater than 10 under the elastic assumption, and the safety factor of the ultimate stable bearing capacity of the structure considering material failure is over 2.0, both meet the safety requirements. © 2019, Editorial Office of Journal of Building Structures. All right reserved.
