基于概率的杆系结构地震易损性分析及其抗震性能评估

发布时间：2018-01-07 20:35

本文关键词：基于概率的杆系结构地震易损性分析及其抗震性能评估　出处：《江西理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：地震易损性可定义为在某一特定地震强度作用下,结构发生破坏的概率,通过对结构进行地震易损性分析可获得在不同等级地震作用下的结构失效概率。因此,基于地震易损性分析的结构抗震性能评估研究就显得尤为重要。本文首先以一钢筋混凝土框架结构为例,对结构进行基于概率的地震易损性分析研究,然后将该研究方法拓展应用于网壳结构的地震失效概率分析,可求得网壳结构的地震易损性曲线,进而对网壳结构展开抗震性能评估。围绕结构的地震易损分析方法,本文开展的研究工作有:首先介绍了结构地震易损性的分析方法和理论,基于该方法,以一九层钢筋混凝土框架结构为例,建立了分析模型,求得其在50条地震动荷载作用下的地震易损性曲线,通过对该易损性曲线分析研究,可知该结构在地震峰值加速度为0.4g时的强震作用下,发生倒塌破坏的概率较低,结构的抗震性能良好,能够满足结构的抗震设防标准。同时通过对比50条与40条,50条与30条,50条与20条,50条与10条地震动记录下求得的地震易损性曲线的离散程度,可知进行框架结构地震易损性分析时采用30条地震动记录计算能够满足精度要求。然后将结构地震易损性分析方法应用于单层网壳结构,以单层球面网壳和单层柱面网壳结构为例,分别求其地震易损性曲线,对该曲线进行分析,得到单层网壳结构的稳定性能良好,能够满足结构的抗震设防标准,即在地面开裂,结构开始毁坏的情况下该结构良好的稳定性可以为人们逃生赢得时间;对比分别采用50条与40条、30条、20条、10条地震动样本下的地震易损性曲线,可知单层柱面网壳与单层球面网壳结构在进行地震易损性分析时30条地震动样本就能满足计算精度要求。最后对地震下具有强度破坏和动力失稳破坏特征的网壳结构分别进行地震易损性分析,获得其地震易损性曲线,通过对比分析可知,动力失稳破坏模型和强度破坏模型的地震易损性曲线有着相似的变化规律,并且符合网壳结构抗震规范对柱面网壳结构抗震性能的要求,这样就说明以网壳结构的性能水准破坏指标来对结构进行基于动力失稳前的地震易损性研究是可行的。采用基于概率的地震易损性分析方法对杆系结构进行地震易损分析适用高效,且分析结果与现行的抗震规范对比具有一致性,为对结构进行概率风险评估提供了简单可靠的研究方法。
[Abstract]:Seismic vulnerability can be defined as the probability of structure failure under the action of a certain earthquake intensity. The failure probability of structure under the action of different magnitude earthquakes can be obtained by analyzing the seismic vulnerability of the structure. It is very important to evaluate the seismic performance of structures based on seismic vulnerability analysis. Firstly, taking a reinforced concrete frame structure as an example, the probabilistic seismic vulnerability analysis is carried out. Then, the research method is extended to the seismic failure probability analysis of reticulated shell structure, and the seismic vulnerability curve of the latticed shell structure can be obtained. Then the seismic performance evaluation of reticulated shell structures is carried out. Around the seismic vulnerability analysis method of the structure, the research work carried out in this paper is as follows: firstly, the analysis method and theory of seismic vulnerability of the structure are introduced, based on this method. Taking the 1-9-story reinforced concrete frame structure as an example, an analytical model is established, and the seismic vulnerability curves under 50 ground motion loads are obtained. It is known that under the action of strong earthquake with a peak acceleration of 0.4g, the probability of collapse and failure of the structure is low, and the seismic performance of the structure is good. It can satisfy the seismic fortification standard of structure. At the same time, by comparing 50 pieces with 40 pieces 50 and 30 pieces 50 and 20. The dispersion degree of seismic vulnerability curves obtained from 50 and 10 seismic records. It is known that the seismic vulnerability analysis of frame structures can meet the accuracy requirements by using 30 seismic records. Then the seismic vulnerability analysis method is applied to single-layer latticed shell structures. Taking single-layer spherical latticed shell and single-layer cylindrical latticed shell as examples, the seismic vulnerability curves are obtained, and the results show that the stability of single-layer latticed shell structure is good and can meet the standard of seismic fortification. That is, when the ground cracks and the structure begins to be destroyed, the good stability of the structure can buy time for people to escape. The seismic vulnerability curves of 50 and 40 or 30 or 20 or 10 ground motion samples were compared respectively. It can be seen that 30 samples of ground motion can meet the requirement of accuracy in seismic vulnerability analysis of single-layer cylindrical latticed shell and single-layer spherical latticed shell structure. Finally, the mesh with the characteristics of strength failure and dynamic instability failure under earthquake can be satisfied. The seismic vulnerability of shell structure is analyzed separately. Through the comparison and analysis, it is known that the dynamic instability failure model and the strength failure model have similar changes in the seismic vulnerability curve. The seismic behavior of cylindrical latticed shell structure is in accordance with the seismic code of latticed shell structure. This shows that it is feasible to use the performance leveling failure index of reticulated shell structure to study the seismic vulnerability of the structure before dynamic instability. The probabilistic seismic vulnerability analysis method is used to carry out the seismic analysis of the bar structure. Vulnerability analysis is applicable and efficient. The analysis results are consistent with the current seismic code, which provides a simple and reliable method for the probabilistic risk assessment of structures.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU311.3;TU323

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