【作者】 杜东升；

【导师】 李爱群；

【作者基本信息】 东南大学 ， 防灾减灾工程及防护工程， 2004， 硕士

【摘要】 建筑结构在地震作用下的破坏是一个十分复杂的过程,一般认为这是由于水平、竖向及扭转地震共同作用的结果。近些年来,钢筋混凝土烟囱、机场控制塔台、超高层建筑大量兴建,这些高耸结构的地震响应规律还未完全认识清楚,对许多震害现象还无法给出合理的解释,而竖向地震对高耸塔台结构的作用更是存在许多争议,因此进行高耸塔台结构地震响应的研究是非常必要的。本文从振动台试验和有限元计算等方面对高耸结构的地震响规律应做了较全面的研究。本文总结了我国自20世纪以来发生的破坏性地震及其造成的经济损失,对高耸结构的水平和竖向地震作用计算方法的研究现状进行了综合评述。以北京机场新塔台为原形进行了1/30的振动台试验,实测了塔台结构的自振周期、振型形状以及各个振型的阻尼比等各项动力特性;实测了塔台结构的地震反应。采用有限元计算程序对试验模型进行时程反应分析,并将计算结果与振动台试验结果进行对比,检验有限元计算软件的可靠性和精确性,为高耸结构的地震反应的进一步理论分析提供可靠的计算工具。根据国内外的强震记录对竖向地震波的幅值和频谱特性进行了探讨,列出了大量认为与竖向地震有关的震害实例。利用大型商业有限元软件SAP2000,取典型高耸结构进行计算,对影响结构竖向动力特性的主要参数进行了分析,认为一般高耸结构的竖向动力特性主要与结构的高度和水平构件质量所占整个结构质量的比例有关,而与结构类型、竖向构件横截面积大小无关。本文根据大量有限元的计算结果提出了高耸结构竖向第一阶自振周期的估算公式。按照规范给出的简化反应谱法和时程分析法对高耸结构竖向地震响应进行了对比计算,对竖向地震的响应规律做了分析,得出高耸结构的竖向顶点位移也主要与结构的高度和水平构件质量所占整个结构质量的比例有关,并根据大量有限元的计算结果提出了高耸结构顶点竖向位移的估算公式以及高耸结构竖向地震作用的简化计算方法。采用有限元程序计算了竖向地震作用、水平地震作用以及竖向地震和水平地震共同作用下高耸塔台结构的非线性地震响应,分析了高耸塔台钢筋混凝土结构在地震作用下的非线性性能,研究了高耸塔台结构在水平地震和竖向地震同时作用下的抗震性能。更多还原

【Abstract】 Destroys resulting from seismic action are quite complicated processes, which are generally supposed to be caused by ground horizontal, vertical and torsional earthquake. The seismic response phenomena of tall flexible tower structures such as reinforced concrete chimney, airport control tower and tall flexible tower buildings have not been studied clearly and some earthquake phenomena have no appropriate explanation. The vertical earthquake action to tall flexible tower structures is still in disputation, hence it is necessary to study the seismic response of tall flexible tower structures. In this paper, research on seismic response of tall flexible tower structures is performed through shaking table test and finite element analysis. The destructive earthquake and the economical loss since 20th century in our country are summarized. The investigation status of horizontal earthquake and vertical earthquake of tall flexible tower structures is commented in detail.A 1/30 scaled reinforced mortar model of a control tower of Beijing airport is tested on shaking table. The dynamic characteristics and seismic response are recorded and analyzed. The dynamic characteristics and seismic response of the prototype structure are derived by the similitude relationship according to the testing results. The dynamic calculations of the model and prototype structures are also performed using structural finite element analysis program, which are compared and analyzed with the test. Range and frequency spectrum of vertical earthquake are studied basing on recorded vertical earthquake waves. Many earthquake Phenomena that are related to vertical seismic response are introduced. The influencing factors to vertical seismic response of tall flexible tower structures are studied by three-dimensional spatial finite element model in the case of typical structure, which reveals that vertical dynamic properties of tall flexible tower structures are mainly relate to height and mass ratio of horizontal members to entire structure. According to the analysis results, the simplified formula of primary vibration period of tall flexible tower structures is presented. The earthquake actions of tall flexible tower structures are computed by response spectrum method and the dynamic calculations method respectively for typical tall flexible tower structures. The computation results reveal that vertical seismic response are also mainly relate to height and mass ratio of horizontal members to entire structure. According to the results, the simplified formula of vertical displacement and vertical earthquake action of tall flexible tower structures under earthquake is presented. The nonlinear seismic responses of tall flexible tower structures under vertical earthquake action, horizontal earthquake action, vertical and horizontal earthquake action together by finite element program are obtained. The nonlinear performance of reinforced concrete structures under earthquake action is analyzed together with the seismic capability of tall flexible tower structures under vertical and horizontal earthquake action together.更多还原