连体高层结构水平耦联振动响应规律理论探讨

Study on horizontal coupled vibration response mechanism of high-rise connecting structure

讨论了连体高层结构在水平地震作用下的耦联振动机理。提出一种"比例之比"理论方法,用以研究连体高层结构不同塔楼在地震作用下的相互"帮扶"规律,推导了基本表达式,在此基础上通过简化算例对理论分析的规律进行验证。基于振型参与系数的基本原理研究连接体对结构总地震力的影响规律,首先对单塔结构高阶振型的参与贡献进行分析,对比了采用伯努利-欧拉梁自由振动理论和假定振型法对高层结构高阶振型参与系数计算结果的一致性,并将假定振型法运用到连体高层结构高阶振型影响的分析中,给出连接体对连体结构总地震力影响规律的理论表达式,结果表明连接体的存在虽然增加了结构的刚度,但总的地震力仍有可能降低,通过简化案例的数值分析也验证了这一结论。

The coupled vibration mechanism of high-rise connecting structure under horizontal seismic load was studied. A new theoretical method of ＂proportion ratio＂ was presented, which was used to study the interaction and mutual helping mechanism between different towers of high-rise connecting structures under the action of earthquakes, and basic formulas were deduced. On this basis, the law of theoretical analysis was verified by a simplified example. The influence of the connector on total seismic force of high-rise connecting structure was studied based on modal participation factor principle. First, participating coefficient of high-order mode for single tower structure in high-modes was analyzed. Modal participation factors of high-order mode based on free vibration theory of Bernoulli-Euler beam and assumed mode shape theory were proved to be identical, and the latter theory method was selected to study the influence of high-order mode for connecting structure. The theoretic expression of the influence of the connector on total seismic force shows that structural stiffness is increased due to the existence of the connector while total seismic force is still likely to decrease. Numerical analyses of the simplified example come to the same conclusion.