高耸结构与高层建筑的竖向地震作用

本文采用时程分析法和反应谱法对烟囱、电视塔、高层剪力墙和高层框架等高耸结构与高层建筑的竖向地震反应进行了分析。其结果表明:1.在烈度为8度强的情况下,结构上部竖向地震内力可达到或超过重力内力;下部竖向地震内力可达重力内力的20％—50％。2.高耸结构与高层建筑竖向地震反应以第一振型为主,据此本文给出了计算高耸结构与高层建筑竖向地震作用的公式,可供抗震设计应用。

Vertical Seismic Action on Highrise Structures and Tall Buildings

The seismic response of highrise structures and tall buildings under vertical ground motion is analyzed by using the step-by-step integration procedure and the response spectrum procedure in this paper. The analysis shows that the vertical seismic internal forces Nv cannot be neglected. In case where the degrees of the earthquake intensity over 8, Nv in the upper part of the structure could reach or exceed the internal forces Ng caused by gravity, and in the lower part Nv could reach 20-50 percent of Ng. The first mode of vibration plays an important role in vertical seismic actions. Formula for calculating vertical seismic load of highrise structures and tall building in seismic design are presented in the paper.