长周期地震动作用下超限高层结构抗震性能研究

发布时间：2018-07-17 21:24

【摘要】：长周期地震动具有峰值加速度相对较低,持时长等特点。历史上发生的历次大地震中记录的长周期地震动表明,震级、震中距和局部场地条件对长周期地震动的产生有十分重要的影响,震级越大,长周期地震动越丰富。本文总结认为,对具有深厚覆盖土层的场地,假设其方圆能产生远场效应的距离有发生大地震的地质构造,就有发生长周期地震动的可能性。长周期地震动会使超限高层等柔性结构产生大位移、高速度及大幅度的摇摆,可能会产生预期之外的损伤和破坏,长周期地震动作用下超高层的抗震性能将会遭受考验。为研究长周期地震动对超限高层结构的影响,本文以兰州红楼时代广场为对象,选取一条普通地震动记录和四条长周期地震动记录分别沿单向和双向对结构进行激励。多遇地震作用下的线性时程分析和罕遇地震作用下的非线性时程分析结果表明,长周期地震动对超限高层结构影响很大。长周期地震动作用下超限高层结构不仅顶点位移远大于普通地震动,结构楼层位移和层间位移角均明显大于普通地震动记录作用下的响应值,其中长周期地震动在小震和大震作用下结构的层间位移角要大于规范规定的层间角位移限值；长周期地震动作用下的结构基底剪力也会超出普通地震动作用下的基底剪力。因此,在有可能发生长周期地震动场地上建设的高层及超限高层建筑,其抗震设计应充分考虑长周期地震动的不利影响。最后,以一未调幅的长周期地震动作用下该超限高层结构的弹性时程分析与普通地震动多遇烈度水准作用下的动力响应分析结果比较表明,长周期地震动作用下结构的动力响应更加明显。因此,应充分重视长周期地震动对超限高层结构的影响。
[Abstract]:Long period ground motion is characterized by relatively low peak acceleration and long duration. The long-period ground motion recorded in all the major earthquakes in history shows that the magnitude, epicentral distance and local site conditions have a very important effect on the generation of long-period ground motion, and the larger the magnitude, the richer the long-period ground motion. In this paper, it is concluded that for a site with deep overlying soil, it is possible to produce periodic ground motion if the geological structure with large earthquake occurs at the distance from which the far field effect can be produced by its square circle. The long-period ground motion will cause large displacement, high speed and large swing of flexible structures such as over-limit tall buildings, which may lead to unexpected damage and damage, and the seismic performance of super-tall buildings will be tested under the action of long-period ground motion. In order to study the effect of long-period ground motion on the over-limited high-rise structure, this paper takes Lanzhou Honglou Times Square as an object, selects one ordinary ground motion record and four long-period ground motion records to excite the structure in one direction and two directions, respectively. The results of linear time-history analysis under frequent earthquake and nonlinear time-history analysis under rare earthquake show that long-period ground motion has great influence on over-limit high-rise structures. Under the action of long-period ground motion, not only the vertex displacement is much larger than that of ordinary ground motion, but also the floor displacement and interstory displacement angle are obviously larger than the response value under the action of ordinary ground motion record. The interstory displacement angle of long-period ground motion under the action of small earthquake and large earthquake is larger than the limit value of interstory angular displacement stipulated in the code, and the base shear force of the structure under long-period ground motion is also higher than that of the base shear force under the action of ordinary ground motion. Therefore, the seismic design of high-rise and over-limited high-rise buildings built on sites where long-period ground motions may occur should fully consider the adverse effects of long-period ground motions. Finally, the elastic time-history analysis of the structure under the action of an unmodulated long-period ground motion is compared with that of the dynamic response analysis under the action of ordinary ground motion intensity leveling. The dynamic response of the structure under long period ground motion is more obvious. Therefore, full attention should be paid to the effect of long period ground motion on overrun tall structures.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.31

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