Microwave Tower Level Of Seismic Performance Analysis

To the high-rise steel structure, it is consistently thought that the structure's design is controlled by the wind load, so the wind-resistance characters are detailedly researched and the structure's earthquake load is neglected. To the communication tower in common use in engineering, only the housetop tower's horizontal vibration-resistance characters is studied in few literatures. The communication towers' horizontal vibration-resistance characters and some main influence factors are studied in this thesis.There are 6 chapters in this thesis. Chapter 1 is a review of the research works of high-rise structures. In chapter 2, the methods to analyses the high-rise structure and the model in this thesis are formulated. In chapter 3, the communication tower's basic characters under horizontal earthquake effect is analyzed, and the flat form, the groundsill, the lighting rod's effect is considered. The result shows us that the groundsill's stiffens has little infection, but the flat form and the lighting rod have more infection. In chapter 4, the influence by the changing of the plat form's mass, height and the lighting rod's mass, stiffness is considered. The result shows us that the structure' s internal force and displacement increases, then descends when the fiat form's mass or height is added, and are added all along with the lighting rod's stiffness and mass's enhance. In chapter 5, the infections by the changing of the ratios of titled pole section vs. the vertical pole section, of the pole section lower part vs. upside, of structure's height vs. width are analyzed one by one. The result shows us that the first ration's incensement brings that the vertical poles' stress becomes greater and the titled poles' stress becomes less and the displacement becomes greater; the first ration's incensement brings the larger stress in section break; the last ration's decline brings the less stress and greater displacement. In chapter 6, the experience formulas about stress and displacement are inferred. These formulas are very simple, and can be used in hand. In these formulas, the process to calculate the load of earthquake as common is not needed. In last part of this thesis, the conclusions of the whole researcher works are reached and some suggestion is put forward.