岩溶区框架结构地震破坏机理研究

发布时间：2018-02-26 22:37

本文关键词： 岩溶框架结构共同作用结构抗震地震破坏　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国大约三分之一的国土面积上分布着岩溶地质,随着经济的发展,越来越多的基础设施将不可避免地在岩溶地区开展建设,针对岩溶地区独特的地质条件,开展岩溶区建筑抗震研究也日益得到重视。现在主流的抗震设计方法仍沿用传统的设计思路,即把地基、基础、上部结构进行单独的抗震分析,同时也缺乏对地震作用下结构破坏机理的研究,这样得出的研究结果和实际情况有所出入,也不能提高岩溶区的建筑抗震性能。因此,开展岩溶区建筑地震破坏机理的研究是很有必要的。本文在总结前人研究成果的基础上,通过分析岩溶地基-筏板基础-框架结构的共同作用和破坏模式来研究其破坏机理,主要工作有：(1)总结了结构抗震理论的发展情况,说明今后的研究热点是基于性能或位移的抗震设计思想；通过总结塑性铰研究的发展情况来简要说明钢筋混凝土结构的地震破坏机理,其破坏模式主要有梁铰模式、柱铰模式和梁柱混合铰模式。(2)分别从地基、基础和上部结构三个方面的分析方法来详细阐述共同作用分析方法的原理,地基刚度、基础刚度和上部结构层数都能对共同作用体系的地震响应造成影响,选择合适的地基、基础、上部结构参数才能增强结构体系的抗震性能。(3)总结了岩溶地基、岩溶区地震破坏的特点及其建筑抗震能力的措施。岩溶区广泛分布着易被水溶解的碳酸盐岩和含有土洞的红黏土层,降低了地基承载力,岩溶地质在地震作用下容易产生岩溶塌陷、地裂缝等危害建筑安全的灾害,同时岩溶区低矮建筑的自振周期接近于地震波的卓越周期容易发生更大的破坏。提高岩溶区的建筑抗震能力,主要从岩溶地质的特点着手,尽量避开承载力低的场地,或对岩溶地基进行处理以提高地基承载力。(4)建立岩溶地基-筏板基础-12层框架结构的共同作用模型、非岩溶地基-筏板基础-12层框架结构的共同作用模型以及不考虑地基的筏板基础-12层框架结构的固基假定模型。先对比岩溶地基和非岩溶地基时上部结构地震反应,结果表明考虑岩溶地基时上部结构的计算结果大于考虑非岩溶地基；再对比共同作用模型和固基假定模型的地震反应,结果表明共同作用模型的计算结果大于固基假定模型。这说明考虑岩溶地基的作用和考虑共同作用的设计方法都可以使结构受地震作用时偏于安全。(5)通过对岩溶地基-筏板基础-5层框架结构的共同作用模型和对应的筏板基础-5层框架结构的固基假定模型进行地震反应分析,得出了以下结论：在多遇地震下,共同作用模型的层间位移角峰值和楼层位移均大于固基假定模型,且前者的层间位移角峰值超过了规范规定的弹性限值,进入了弹塑性阶段,有着破坏的危险。这说明传统的固基假定设计方法忽略了结构进入弹塑性状态的危险,更容易引发结构的地震破坏；在罕遇地震下,两个模型的地震波加载末楼层位移以及层间位移角峰值没有太大差距,而且没有超过规范规定的限值,这说明共同作用设计方法对结构在罕遇地震下的抗震性能改变帮助不大；两个模型在罕遇地震下,大部分构件都将进入弹塑性状态,分别对它们的塑性区发展过程进行研究后,可以看出共同作用模型的塑性区发展符合“强柱弱梁”的屈服机制,而固基假定模型的框架柱出现了太多塑性区,框架柱承受了太多的地震能量会更容易发生破坏。所以,共同作用设计方法可以在一定程度上对结构的受力性能进行优化,加强结构的抗震性能。
[Abstract]:About 1/3 of China's land area distribution of karst geology, with the development of economy, more and more infrastructure will inevitably carry out construction in the karst area, according to the unique geological conditions in karst area, to carry out seismic research on karst area construction becomes more and more important. Now the seismic design method of the mainstream is still using the traditional design ideas that is the foundation, foundation, analysis of the seismic structure, but also the lack of research on the failure mechanism of the structure under the action of earthquake, so that the result of the research and the actual situation is out, can improve the seismic performance of buildings in Karst Area. Therefore, research on Karst building earthquake damage mechanism is very necessary in this article. Based on the results of previous studies, to study through the analysis of the interaction and the failure modes of karst foundation raft foundation frame structure The failure mechanism, the main work is: (1) summarizes the development of seismic theory, explains the research hotspots in the future is the idea of seismic design based on performance or displacement; by briefly summarizes development of plastic hinge on the destruction mechanism of reinforced concrete structure of the earthquake, the failure modes of main beam model column and beam column hinge model, mixed hinge model. (2) respectively from the three aspects of analysis method of foundation, foundation and superstructure to elaborate the principle of interaction analysis method, foundation stiffness and foundation stiffness and the upper layers of the structure can affect the response of the interaction system of the earthquake, choose the right the foundation, foundation, seismic performance of the structure system of the upper structure parameters can be enhanced. (3) summarizes the karst foundation, characteristics of earthquake damage in karst area and building aseismic capacity measures. Karst area are widely distributed and easy Is the carbonate dissolved in water and soil of the red clay layer containing hole, reduces the bearing capacity of foundation, karst prone to karst collapse in the earthquake, ground fissure hazards such as construction safety hazards, and karst area of low rise building since the predominant period of the vibration cycle is close to earthquake prone to greater damage. To improve the seismic capacity of buildings in karst area, the main characteristics of karst to try to avoid the low bearing capacity of the site, or to the karst foundation treatment in order to improve the bearing capacity of the foundation. (4) the interaction model of karst foundation raft foundation -12 layer frame structure, the interaction of non karst soil raft foundation the -12 layer frame structure model and without considering the solid base of raft foundation -12 layer frame structure model. The first comparison of karst foundation assumption and non karst foundation when the seismic response of the superstructure, the results show that considering rock Solution when the foundation of the calculation of the upper structure is greater than the considered non karst foundation; and then compare the interaction model and the solid base of the seismic response of the assumed model. The calculation results show that the interaction of the model results than the solid base of the assumed model. This means that the consideration of the karst foundation role and consider with the interaction design method can make the structure under earthquake action when on the safe side. (5) the seismic response analysis by the solid base of raft foundation on karst foundation raft foundation -5 layer frame structure model and the corresponding -5 layer frame structure of the assumed model, drew the following conclusions: in the earthquake, the interaction model of the drift angle the peak and floor displacement are larger than the solid base of the assumed model, and the layer displacement angle exceeds the peak specification of the elastic limit, entered the plastic stage, with the destruction of danger. This shows that the traditional The solid base of assumed design methods ignore the risk structure in elastic-plastic state, are more likely to cause damage to the structure of the earthquake; under rare earthquake, the two models of seismic wave loading at the end of the floor displacement and inter story displacement angle peak is not much difference, but did not exceed the specification limits the interaction the design method of change contributes little to the seismic performance of the structure under rare earthquake; two model under rare earthquake, most of its members will enter the elastic-plastic state, respectively, to study the plastic zone of the process of their development, we can see that the development of plastic zone interaction model with the yield mechanism of strong column weak beam ", and the solid base of frame column of the assumed model showing too much plastic zone, frame columns under too much seismic energy to be more prone to damage. Therefore, the interaction design method can to a certain extent. The mechanical performance of the structure is optimized and the seismic performance of the structure is strengthened.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P315.9;TU311.3

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