岩溶地区高层框架结构抗震性能研究

发布时间：2018-05-05 14:29

本文选题：岩溶地基 + 高层框架结构　；参考：《广西大学》2013年硕士论文

【摘要】：我国可溶性岩石分布广泛,类型众多,在复杂的岩溶地基上建造高大建筑物,给工程人员提出了许多新的问题与挑战。目前我国针对岩溶区建筑结构的抗震研究较少,本文采用数值模拟分析方法,基于共同作用,研究岩溶地质对上部框架结构抗震性能影响,为岩溶区的建筑工程提供参考借鉴,主要工作有： (1)探讨了岩溶区的地质特点,采用Drucker-Prager本构模型对地基进行模拟,并对模型中各参数的取值进行深入讨论。岩溶区的可溶性岩层以碳酸盐岩的分布最广,红粘土的分布最为典型。碳酸盐岩有很好的力学性质,但由于其自身可溶性而常发育有溶洞,溶槽等削弱其承载力。岩溶区红粘土的分布具有上硬下软的特点,其含水率比一般性的粘土要大,却有很高的承载力,土层中常发于有土洞。 (2)对岩溶场地地基模型进行常遇地震下的地震反应分析,研究地震波在岩溶地质条件下的传播特点：岩溶场地的土层对地震波有一定“滤波作用”,接近场地的自振频率的分量被充分保留,由于岩溶地基刚度大,保留下来的频率偏高；岩溶场地土层对地震波有一定的放大效应,当岩溶地基中发育有土洞时,这种放大效应加强。 (3)分别采用固基假定的分析方法和共同作用分析方法对岩溶地基上的框架结构做地震反应分析,对比两种地震反应分析方法的计算结果。与固基假定的分析模型相比,共同作用模型得到的上部结构的位移增大,中下层柱剪力增加,中上层柱的剪力减少,最大剪力发生在内柱底层。 (4)基于地基—基础—框架结构共同作用的有限元地震反应分析,研究了岩溶地基中土洞的发育对上部框架结构地震反应的影响：土洞的存在会导致上部结构地震反应增强,对结构抗震造成不利。 (5)基于岩溶地基—基础—框架结构共同作用的有限元地震反应分析,研究岩溶地基刚度的变化对上部框架结构抗震性能的影响。研究表明,地基的刚度越大,上部结构的地震反应越强,因此,对于刚度较大岩溶地基,有必要加强其上部的高层框架结构的抗震能力。
[Abstract]:There are many kinds of soluble rocks in China. The construction of tall buildings on the complex karst foundation brings many new problems and challenges to engineers. At present, there is little research on seismic resistance of building structure in karst area in our country. In this paper, numerical simulation analysis method is used to study the influence of karst geology on seismic performance of superframe structure, which provides reference for building engineering in karst area. The main tasks are: 1) the geological characteristics of karst area are discussed, the foundation is simulated by Drucker-Prager constitutive model, and the values of each parameter in the model are discussed in depth. In karst area, carbonate rock is the most widely distributed and red clay is the most typical. Carbonate rocks have good mechanical properties, but they often develop caverns because of their own solubility, which weaken their bearing capacity. The distribution of red clay in karst area is characterized by the hardness and softness. The water content of red clay is larger than that of common clay, but it has a high bearing capacity. 2) analyzing the seismic response of the foundation model of karst site under frequent earthquakes, and studying the propagation characteristics of seismic wave under karst geological conditions: the soil layer of karst site has certain "filtering effect" on seismic wave. The component of the natural vibration frequency near the site is fully preserved, because of the large stiffness of the karst foundation, the reserved frequency is on the high side, the soil layer of the karst site has a certain amplification effect on the seismic wave, and when there are soil holes in the karst foundation, This amplification effect is reinforced. 3) the seismic response of frame structure on karst foundation is analyzed by using the analysis method of fixed foundation assumption and the method of interaction analysis, and the results of the two seismic response analysis methods are compared. Compared with the analysis model based on the fixed foundation assumption, the displacement of the superstructure obtained by the interaction model increases, the shear force of the middle and lower column increases, the shear force of the upper column decreases, and the maximum shear force occurs at the bottom of the inner column. 4) based on the finite element seismic response analysis of the interaction between foundation, foundation and frame structure, the influence of the soil hole development on the seismic response of the upper frame structure is studied: the existence of the soil hole will lead to the enhancement of the seismic response of the superstructure. It is unfavorable to the earthquake resistance of the structure. 5) based on the finite element seismic response analysis of karst foundation-foundation-frame structure, the influence of the change of karst foundation stiffness on the seismic behavior of the upper frame structure is studied. The results show that the stronger the stiffness of the foundation is, the stronger the seismic response of the superstructure is. Therefore, it is necessary to strengthen the seismic capacity of the upper high-rise frame structure for the karst foundation with higher stiffness.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.31

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