【作者】 王志从；

【导师】 王震宇；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2011， 硕士

【摘要】 非延性钢筋混凝土框架是指没有进行抗震设计、仅用来承担竖向荷载和风荷载,或由于抗震设计规范的修订而不能满足目前抗震要求的现役钢筋混凝土框架结构,这类结构由于缺乏足够的延性和耗能能力,在罕遇地震作用下存在着极高的倒塌风险,急需抗震加固才能继续使用。本文对不同高度非延性钢筋混凝土框架结构进行了碳纤维加固前后的弹塑性静、动力抗震分析,在此基础上提出碳纤维抗震加固非延性钢筋混凝土框架结构的概念设计原则,为进一步提出碳纤维抗震加固此类框架结构的量化设计方法奠定基础,对完善和发展我国混凝土结构加固设计规范具有重要意义。本文主要研究工作如下:1.结合Perform-3D有限元分析软件,分别建立了伪静力与振动台Benchmark试验的有限元模型,通过与试验结果的对比分析,验证了本文在Perform-3D中建模及弹塑性静、动力分析过程的正确性与适用性;2.为探讨不同高度非延性钢筋混凝土框架结构采用碳纤维片材加固后的抗震性能,用PKPM按不考虑抗震设防的原则设计了五层(低层)、十层(中层)、十五层(高层)钢筋混凝土框架结构;在Perform-3D非线性分析软件中实现了碳纤维加固前后框架结构的有限元模型,采用弹塑性静力Pushover方法和动力时程反应分析方法,对加固前后框架结构的抗震性能进行分析与评价;3.通过加固前后不同高度框架结构的抗震性能分析,对比多种加固方案的抗震加固效果,提出碳纤维抗震加固非延性钢筋混凝土框架结构的概念设计原则:碳纤维加固框架梁、构件柱对结构的初始弹性刚度影响很小,但可以提高结构的承载力和延性;加固后存在结构薄弱层转移的现象,结构的失效模式可能改变;碳纤维加固低层框架时加固效果最好,加固中、高层框架时的抗震性能提高不如加固低层框架时明显;对于低层框架结构,仅加固框架柱就能大幅提高结构的抗震性能,同时加固框架梁、柱与仅加固框架柱的效果相当;而对中、高层非延性框架结构,只加固框架柱并不能有效地提高结构的抗震性能,需要同时加固框架梁和框架柱才能更好地提高结构的抗震性能。更多还原

【Abstract】 The non-ductile reinforced concrete (RC) frames refer to the frames that bears only vertical load and wind load, none considering seismic load, and the frames that cannot satisfy the present seismic requirements due to the revision of design code. These kinds of structures lack of enough ductility and energy dissipation capacity, so there is high risk of collapse in future earthquake events. Many of existing RC frames that designed according to the old design code needs to be strengthened for reducing the risk of structural collapses during earthquakes.The objective of this study is to evaluate analytically the seismic performance of retrofitted non-ductile RC frames with different height using Carbon Fiber-Reinforced Polymer (CFRP). Pushover and time history analysis were conducted for the studied cases. On the basis of analytical results, the concept design principle of CFRP retrofitting non-ductile RC frames is proposed. The investigation of this study is the basic work for presenting the seismic retrofitting design method of non-ductile RC frames using FRP wraps and significantly for developing and improving of the seismic retrofitting design code of concrete structure in our country. The main contents of the thesis are summarized as follows:1. The finite element analysis software Perform-3D was used to conduct Pushover and time history analysis. To validate the capacity and accuracy of the analyzed results, firstly a quasi-static cyclic test and a shaking table Benchmark test were simulated using the software, respectively. The comparisons between the test results and predictions of Pushover and time history analysis demonstrate the capacity and excellent accuracy of the software.2. Three non-ductile RC frames with different heights representing low- (5 floors), medium- (10 floors), and high-rise (15 floors) buildings as control specimens were designed and investigated Then the finite element model of three non-ductile frames and retrofitted frames using different rehabilitation patterns were modeled in Perform-3D. The seismic performance of the control and retrofitted RC frames was evaluated using the Pushover and dynamic time history analysis.3. The retrofitted effectiveness of different rehabilitation patterns is evaluated from the comparing of seismic performance control and retrofitted frames. It is found that the bearing capacity and the ductility of RC frames are improved after retrofitting, while the elastic stiffness is unchanged. The weakness floors may be transferred for retrofitted frames and then change the failure mode of retrofitted frame. The retrofitted effectiveness is best when retrofitting the low-rise frames. For the low-rise frames, the FRP rehabilitation of columns only is effective in enhancing the seismic performance and retrofitting both beams and columns perform the same as retrofitting columns only. For medium- and high-rise ones, rehabilitation of columns only cannot improve the seismic performance of frames and it is necessary to retrofitting both the frame beams and columns for these frames.更多还原