超高层混凝土结构稳定性计算方法对比研究

Comparative study on calculation method for stability of super high⁃rise building concrete structure

刚重比是影响重力P-Δ效应的主要参数,是反映结构整体稳定性的主要因素。高规的刚重比公式适用于竖向荷载沿高度均匀分布的结构,对于非均布荷载或体型复杂的超高层建筑,用高规的刚重比公式计算偏保守、存在缺陷。在论述刚重比与临界屈曲荷载因子之间的关系基础上,提出了直接采用有限元屈曲分析法。对比了不同规范对结构稳定的设计思路和判别方法,研究了影响刚重比的主要因素,并对深圳某超高层建筑的4种力学模型验算了结构稳定性。结果表明:直接采用有限元屈曲分析法得到的超高层建筑结构临界屈曲荷载因子作为判别结构稳定的依据满足安全要求。

The stiffness⁃weight ratio is the main parameter affecting the gravity P⁃Δeffect and the main factor reflecting the overall stability of the structure.The stiffness⁃weight ratio formula of the high⁃rise specification is suitable for structures with uniform vertical load distribution along the height.For super high⁃rise buildings with non⁃uniform load or complex shape,the calculation of the stiffness⁃weight ratio formula of the high⁃rise specification is conservative and flawed.On the basis of discussing the relationship between the stiffness⁃weight ratio and the critical buckling load factor,a direct finite element buckling analysis method was proposed.The design ideas and discriminant methods of structural stability in different codes were compared,and the main factors affecting the stiffness⁃weight ratio were studied.The structural stability of four mechanical models of a super high⁃rise building in Shenzhen was checked.The results show that the critical buckling load factor directly obtained by the finite element buckling analysis method is used as the basis for judging the stability of the super high⁃rise building structure to meet the safety requirements.