框架填充墙结构及碳纤维加固后的抗震性能分析.pdf
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1、哈尔滨工业大学工学硕士学位论文 - II - 构整体抗震性能较差; (4) 填充墙的存在使结构所能抵抗的最大地震动加速度峰值 降低,削弱了结构的抗震能力,更易形成“强梁弱柱”的破坏机制;(5) 碳纤维加 固全填充框架结构的合理方法是加固首层框架梁与柱,而对底部大空间结构,仅 加固框架梁、柱并不能显著提高结构的整体抗震性能,应采取其它更为有效的加 固方法,比如在首层增加填充墙或剪力墙等措施。 关键词:钢筋混凝土框架填充墙结构;碳纤维;抗震加固;Perform-3D;弹塑性静 力分析;弹塑性动力时程分析 哈尔滨工业大学工学硕士学位论文 - III - Abstract During the Wen
2、Chuan earthquake in 2008, the RC frames with infill wall suffered serious damages, and the failure mechanism of “strong columns and weak beams” for frame structures which was actively implemented by every country almost did not get any reflection. As a result of the constraint enhancement of infill
3、wall to the flexural rigidity of the frame beams, the plastic hinges appeared in the upper and bottom end of the column for the majority of infilled frames, thus leading to the collapse of the whole structure, and the damage mechanism of “strong beams and weak columns” was showed by the frames. Simu
4、ltaneously, failure of weak floor due to the discontinuous of infill wall along the vertical direction of the building, torsion damage due to the asymmetric plane layout of the infill wall, shear failure of the short column due to the presence of the wall between the windows, casualties and escape r
5、oute blocking due to the collapse of the infill wall had been seen everywhere. The serious damages of infilled RC frames in WenChuan earthquake had aroused wide attention and thinking in the civil engineering filed of our country, and people start to review the collaborative work mechanism between t
6、he infill wall and frame, as well as the influences of infill wall on the frame structures overall seismic performance. After the WenChuan earthquake event, the design requirements for infilled frame structures have been improved in our newly issued seismic codes, thus causing most of the existing i
7、nfilled frames designed according to old codes to fail to meet the requirements of the new codes. Facing the possibility of earthquake disasters at any time, it is better for us to rehabilitate existing infilled RC frame structures before the earthquake rather than implement large-scale demolition a
8、nd reconstruction in order to alleviate the seismic risks faced by existing structures. The seismic retrofit for existing infilled RC frames before the earthquake happens has been made an extremely urgent matter by the painful experience in WenChuan earthquake. In this paper, the influence law of in
9、fill wall on the frames and the appropriate methods of seismic retrofit for infilled frame structures using CFRP were investigated, and the main contents of the study were summarized as follows: 1. The equivalent diagonal strut model used to simulate the infill wall was determined first, and then th
10、e quasi static and shaking table test was conducted numerical simulation analysis using Perform-3D software, respectively. The correctness of pushover and time history analysis based on Perform-3D, including the equivalent diagonal strut model was proved by comparing the calculated results to the te
11、st records; 2. Based on Perform-3D software, the static and dynamic analyses for two kinds of infilled frames were conducted, and they referred to frames with infill wall arranged in every story and only in two to top story, respectively. By comparing with the analysis 哈尔滨工业大学工学硕士学位论文 - IV - results
12、 of bare frame, the influences of infill wall on the overall seismic performance of these two structures have been determined; 3. Different retrofit schemes using CFRP were designed for these two structures, and the overall seismic performance of retrofitted frame versus frame without retrofit were
13、compared under different retrofit schemes, finally, the appropriate retrofit methods by CFRP of infilled RC frames were determined. Based on the study above, several conclusions have been obtained: (1) For the first infilled RC frame, the lower vibration modes of the structure were significantly inf
14、luenced by the infill wall, and the reduction coefficient of natural periods of vibration were distributed between 0.4 and 0.6; (2) When considering the effect of infill wall, the lateral bearing capacity and stiffness of the first frame was 1.7 and 5 times that of the bare frame, respectively, whil
15、e for the second infilled frame, the lateral bearing capacity changed a little; (3) Due to the stiffness contribution of infill wall, the deformation capacity of infilled frame were reduced dramatically, especially for the second frame, the first story was more inclined to be the weak floor, and onl
16、y columns in the first story were the main energy-consuming components under the seismic action, the overall seismic performance of the structure was bad; (4) The peak acceleration of the maximum ground motion which the structure can resist was reduced while the effects of infill wall were included,
17、 and the seismic ability of the structure was weakened, simultaneously, the frame was more easily to form the failure mechanism of “strong beams and weak columns”; (5) For the first frame, the beams and columns in the first story need to be retrofitted by CFRP, while for the second frame, the overal
18、l seismic performance of the structure can not be improved significantly by just retrofitting the frame beams and columns, so other more effective methods should be used to retrofit this frame, such as adding the infill wall or shear wall at the first floor of the building. Keywords: Infilled RC fra
19、me structure, CFRP, seismic retrofit, Perform-3D, elastic-plastic static analysis, elastic-plastic dynamic time history analysis 哈尔滨工业大学工学硕士学位论文 - V - 目 录 摘 要 . I Abstract . III 第 1 章 绪 论 1 1.1 课题背景及意义 . 1 1.2 框架填充墙结构的震害调查 . 2 1.3 框架填充墙结构抗震性能的研究现状与分析 . 6 1.3.1 试验研究 6 1.3.2 理论分析 8 1.4 碳纤维加固填充墙框架结构研究现
20、状 . 13 1.4.1 试验研究 13 1.4.2 理论分析 15 1.5 本文主要研究内容 . 16 1.6 本文技术路线 . 17 第 2 章 Perform-3D 软件弹塑性分析方法验证 18 2.1 引言 . 18 2.2 Perform-3D 软件介绍 18 2.3 填充墙等效斜撑模型 . 20 2.3.1 等效斜撑模型发展概况 20 2.3.2 本文采用的等效斜撑模型介绍 25 2.4 Perfrom-3D 软件的试验验证 27 2.4.1 伪静力试验验证 27 2.4.2 振动台试验验证 31 2.5 本章小结 . 36 第 3 章 全填充框架填充墙结构的抗震性能分析 37 3
21、.1 引言 . 37 3.2 框架填充墙结构的设计 . 37 3.3 Perfrom-3D 有限元建模 39 3.4 全填充框架抗震性能分析 . 41 3.4.1 模态分析 41 3.4.2 弹塑性静力 Pushover 分析 . 41 3.4.3 弹塑性动力时程分析 46 3.5 本章小结 . 51 哈尔滨工业大学工学硕士学位论文 - VI - 第 4 章 底部大空间填充墙框架结构抗震性能分析 53 4.1 引言 . 53 4.2 Perform-3D 有限元建模 54 4.3 底部大空间填充墙框架抗震性能分析 . 55 4.3.1 弹塑性静力 Pushover 分析 . 55 4.3.2
22、弹塑性动力时程分析 59 4.3.3 地震作用下的耗能分析 62 4.4 本章小结 . 64 第 5 章 碳纤维加固填充墙框架的抗震性能分析 66 5.1 引言 . 66 5.2 加固方案及 CFRP 约束混凝土本构 . 66 5.2.1 加固方案的确定 66 5.2.2 CFRP 约束混凝土本构 67 5.3 CFRP 加固全填充框架的抗震性能分析 . 70 5.3.1 弹塑性静力 Pushover 分析 . 70 5.3.2 弹塑性动力时程分析 73 5.4 CFRP 加固底部大空间框架的抗震性能分析 . 76 5.4.1 弹塑性静力 Pushover 分析 . 76 5.4.2 弹塑性动
23、力时程分析 79 5.5 本章小结 . 82 结 论 84 参考文献 85 哈尔滨工业大学学位论文原创性声明及使用授权说明 . 90 致 谢 91 哈尔滨工业大学工学硕士学位论文 - 1 - 第1章 绪 论 1.1 课题背景及意义 框架填充墙结构是指为了围护和分割空间、在梁柱间砌筑填充墙而形成的组 合结构,由于其空间布置灵活,被广泛应用于多高层民用建筑。目前多数国家的 抗震规范依然采用纯框架“强柱弱梁”的设计理念来考虑框架填充墙结构的抗震 设计,将填充墙作为非结构构件处理而忽略其对结构整体抗震性能的影响,我国 规范建议采用0.60.7的结构基本周期折减系数,通过增大水平地震力的方法来考 虑填充
24、墙对框架结构刚度的贡献。在2008年汶川地震中,框架填充墙结构发生了 较为严重的震害,各国规范积极贯彻的“强柱弱梁”抗震思想几乎没有体现,由 于楼板与填充墙对框架梁抗弯刚度的约束增强作用,导致许多框架填充墙结构在 柱端出现塑性铰、进而引发结构的整体倒塌,结构呈现出“强梁弱柱”的破坏机 制。同时,填充墙沿结构竖向布置不连续造成的结构薄弱层失效、填充墙平面布 置不对称造成的结构扭转破坏、窗间墙造成框架柱发生的短柱剪切破坏、填充墙 倒塌造成的人员伤亡及阻塞逃生通道等震害表现也随处可见。汶川地震中框架填 充墙结构的震害引起了我国土木工程界的广泛关注与思考,开始重新审视填充墙 与框架间的协同工作机制以及
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- 框架 填充 结构 碳纤维 加固 抗震 性能 分析
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