动臂式施工塔吊TMD地震响应控制与分析

虽然建筑施工周期内地震致险概率并不高,但是由于塔吊使用极其广泛,塔吊致险概率并不低于建筑结构,故而针对塔吊的减震措施亟需研究。本文以某实际超高层建筑施工使用的动臂式塔吊为研究对象,根据塔吊自身和附着于超高层建筑后的动力特性,研究了TMD装置的不同方案对塔吊地震响应的控制效果。结果表明:(1)TMD装置对于属于高耸结构的塔吊减震控制非常有效;(2)设置在塔身顶部的双向TMD不仅可以有效减小塔身偏摆,也可以间接有效地控制起重臂的竖向振动;(3)由于超高层建筑-塔吊结构高阶振型影响明显,此TMD装置对塔吊塔身控制效果不稳定,但对于起重臂仍能起到良好的控制作用,故而此TMD装置可以使用在附着在超高层建筑上的施工塔吊,对于塔身的振动控制仍需进一步研究。

A statistically refined Bouc-Wen model for the identification of structures under tri-directional seismic excitations

This paper presents a statistically refined Bouc-Wen model of tri-axial interactions for the identification of structural systems under tri-directional seismic excitations. Through limited vibration measurements in the National Center for Research on Earthquake Engineering in Taiwan conducting model-based experiments, the 3-D Bouc-Wen model has been statistically and repetitively refined using the 95% confidence interval of the estimated structural parameters to determine their statistical significance in a multiple regression setting. When the parameters＇ confidence interval covers the ＂null＂ value, it is statistically sustainable to truncate such parameters. The remaining parameters will repetitively undergo such parameter sifting process for model refinement until all the parameters＇ statistical significance cannot be further improved. The effectiveness of the refined model has been shown considering the effects of sampling errors, of coupled restoring forces in tri-directions, and of the under-over-parameterization of structural systems. Sifted and estimated parameters such as the stiffness, and its corresponding natural frequency, resulting from the identification methodology developed in this study are carefully observed for system vibration control.

黏滞性阻尼器在超高层建筑施工塔式起重机中的减震控制研究

为研究超高层建筑施工塔吊的减震措施,采用黏滞阻尼器作为附加消能杆件,建立超高层建筑-施工塔吊系统有限元模型,通过数值分析优选布置方案及阻尼器性能参数。以某超高层建筑施工动臂式塔吊为研究背景,设计缩尺比为1∶15的简化试验模型,并对有控结构和无控结构模型进行振动台试验。结果表明：试验采用的阻尼器布置方案减震效果良好;超高层建筑施工塔吊的应力热区为吊臂与塔身顶部连接处、平衡臂与塔身顶部连接处及塔身顶部,设置黏滞性阻尼器明显降低了塔吊应力热区的应力值;激励强度是影响阻尼器减震效果的主要因素之一,激励强度越大减震效果越好。