新规范梁柱设计参数对实现RC框架结构屈服机制的影响研究

发布时间：2018-04-19 19:54

本文选题：现浇框架结构 + 强柱弱梁　；参考：《西安建筑科技大学》2013年硕士论文

【摘要】：对于现浇钢筋混凝土框架结构，“强柱弱梁”破坏模式较为理想。但在汶川大地震中，这种良好的耗能结构发生的是“强梁弱柱”破坏模式，大部分框架结构的柱端出现塑性铰，说明现行抗震设计规范中的梁柱设计参数存在不合理之处。影响“强柱弱梁”破坏模式实现的影响因素很多，本文仅对主要影响因素进行定性分析，即重点研究框架梁刚度放大系数与框架柱弯矩放大系数对实现这种破坏模式的影响。论文研究内容如下：首先，研究框架梁刚度放大系数对“强柱弱梁”屈服机制实现的影响。分别对7度设防三级抗震框架、8度设防二级抗震框架和9度设防一级抗震框架模型做Pushover分析，其中刚度放大系数设定为1.8、2.0、2.2和2.4。通过比较不同刚度放大系数下结构的破坏模式、楼层位移、层间位移和大震下的层间位移角来确定结构框架梁刚度放大系数的合理取值。其次，研究框架柱弯矩放大系数对“强柱弱梁”屈服机制实现的影响。分别对6度设防四级抗震框架、7度设防三级抗震框架、8度设防二级抗震框架和9度设防一级抗震框架模型做Pushover分析，其中弯矩放大系数设定为0.8~2.2，并且6、7、8、9度设防的框架结构都含有原始结构模型，即弯矩放大系数分别为1.2、1.3、1.5、1.7。通过比较不同刚度放大系数下结构的破坏模式、楼层位移、层间位移和大震下的层间位移角来确定结构框架柱弯矩放大系数的合理取值。最后，通过上述得出的框架梁刚度放大系数与框架柱弯矩放大系数参考建议值并结合一个实际的工程算例，重新进行设计计算，通过动力弹塑性时程分析与Pushover分析比较研究原始结构和调整后结构的破坏模式和大震下的层间位移角，进而验证参数的合理性。根据本文典型框架算例分析得出，框架中梁的刚度放大系数对于6度设防四级抗震框架按照规范取值，7度设防三级抗震框架、8度设防二级抗震框架和9度设防一级抗震框架都取1.8。框架柱弯矩放大系数对于6度设防四级抗震框架按规范取值，，7度设防三级抗震框架和8度设防二级抗震框架都取2.0,9度设防一级抗震框架取2.0或2.2。通过实际算例分析得出上述梁柱设计参数建议值合理。
[Abstract]:For cast-in-place reinforced concrete frame structure, the failure mode of "strong column and weak beam" is ideal. However, in Wenchuan earthquake, this kind of good energy dissipation structure occurred in the "strong beam weak column" failure mode, and plastic hinge appeared at the end of most frame structure, which indicates that Liang Zhu design parameters in the current seismic design code are unreasonable. There are many factors influencing the failure mode of "strong column and weak beam". This paper only analyzes the main influencing factors, that is, the influence of stiffness magnification factor of frame beam and moment magnification factor of frame column on the realization of this failure mode. The contents of this thesis are as follows: Firstly, the effect of stiffness magnification factor of frame beam on the yield mechanism of "strong column and weak beam" is studied. Pushover analysis was made for the models of the 7-grade three-grade seismic frame with 8 degrees and the model of the 9-degree first-grade seismic frame, in which the stiffness magnification factor was set as 1.82.02.2and 2.4. By comparing the failure mode, floor displacement, floor displacement and interstory displacement angle under different stiffness magnification coefficient, the reasonable value of stiffness magnification factor of frame beam is determined. Secondly, the effect of moment magnification factor of frame column on the yield mechanism of "strong column and weak beam" is studied. In this paper, Pushover analysis is made for the model of the 6 degree fortification grade 4 earthquake resistant frame with 7 degree fortification grade 3 earthquake resistance frame and the second grade seismic frame with 8 degree fortification and 9 degree fortification grade 1 seismic frame, respectively. Among them, the moment magnification factor is set to 0.8 ~ 2.2and the frame structure with 6 ~ 7 ~ 8 ~ (9) degree fortification contains the original structure model, that is, the moment magnification factor is 1.2 ~ (1.3) / 1. 5 / 1. 7 respectively. By comparing the failure mode, floor displacement, floor displacement and interstory displacement angle under different stiffness magnification factors, the reasonable value of moment magnification factor of frame columns is determined. Finally, the frame beam stiffness magnification coefficient and the frame column bending moment magnification coefficient are calculated and recalculated by a practical engineering example. By comparing the dynamic elastic-plastic time history analysis with the Pushover analysis, the failure mode of the original structure and the adjusted structure and the interstory displacement angle under the strong earthquake are studied, and the reasonableness of the parameters is verified. According to the analysis of typical frame examples in this paper, The stiffness magnification factor of the beam in the frame is 1.8 for the 6-degree fortification four-stage seismic frame according to the code, the 7-degree fortification three-stage seismic frame, the 8-degree fortification second-grade seismic frame and the 9-degree fortification first-grade aseismic frame. The moment magnification factor of frame column is calculated according to the code for the 6 degree fortification four grade seismic frame and the 7 degree fortification grade 3 earthquake resistant frame and the 8 degree fortification grade 2 earthquake resistant frame. The first grade seismic frame is 2.0 or 2.2 for the 6 degree fortification grade 4 seismic frame and the 8 degree fortification grade 2 earthquake resistant frame. A practical example analysis shows that the suggested value of Liang Zhu's design parameters is reasonable.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375.4

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