体型收进对高层建筑结构抗震性能的影响及控制方法研究

发布时间：2018-01-03 20:44

本文关键词：体型收进对高层建筑结构抗震性能的影响及控制方法研究　出处：《中国建筑科学研究院》2015年博士论文　论文类型：学位论文

【摘要】：体型收进是高层建筑一种较为常见的不规则类型,主要表现为裙房顶进、立面退台收进、顶部收进和核心筒内缩。历次震害表明,收进部位往往在强震中首先破坏,导致结构整体抗震能力尚未充分发挥就因局部严重破坏而失去继续承载的能力。本文围绕体型收进对高层建筑带来的竖向不规则问题,重点就体型收进对钢筋混凝土框架结构和框剪结构抗震性能的影响及其控制方法展开研究。主要工作及研究成果如下:(1)基于连续化方法建立了沿高度变刚度结构的简化分析模型,推导过程中考虑了柱轴向变形的影响。与有限元模型的对比结果表明,简化分析模型不仅具有良好的计算精度,而且计算效率较高。利用简化分析模型系统研究了体型收进对框架和框剪结构弹性地震反应的影响,结果表明体型收进会改变结构侧向变形的连续性和鞭梢效应的强弱程度。收进位置相邻上、下层侧向刚度比γ与侧向变形的连续性、鞭梢效应的强弱程度有明显相关关系,适合作为体型收进的控制指标。(2)严格按照我国现行规范设计了收进程度不同的一组框架结构和一组框剪结构,通过动力弹塑性分析研究了收进位置相邻上、下层侧向刚度比γ和结构弹塑性地震反应的关系,从刚度退化、层间变形、屈服模式等方面论证了采用γ作为收进程度控制指标的合理性。结果表明,层刚度取层剪力与层间位移之比,当框架结构γ1小于0.7时,收进位置相邻上层柱底会较早屈服;层刚度取层剪力与层间位移角之比,当框剪结构γ2小于0.9时,收进位置相邻上层墙肢底部会较早屈服。建议框架结构γ1不宜小于0.7,框剪结构γ2不宜小于0.9。(3)深入分析了收进部位的竖向构件在强震作用下较早屈服的原因,结果表明抗震薄弱部位的形成与正截面承载力冗余系数ρ相关。所以,根据ρ可以判断抗震薄弱部位。但是,对有多道抗震防线的结构,塑性内力重分布会影响判断结果的准确性。提出了构件冗余系数的改进算法,以8层框架结构和24层框剪结构为例加以验证,结果表明,抗震薄弱部位的判断结果与动力弹塑性分析结果一致。(4)为了解决收进部位的竖向构件在强震下较早屈服的问题,提出了基于预设屈服模式的抗震性能化设计方法。结构构件分为关键构件和耗能构件。首先根据层刚度比设定关键构件性能目标,然后利用等能量原则计算耗能构件的抗弯刚度折减系数,假定关键构件保持弹性,通过中、大震等效线性反应谱分析得到关键构件的抗震承载力需求。采用本文方法和现行规范方法分别设计了收进位置相邻上、下层侧向刚度比小于建议限值的框架结构和框剪结构,动力弹塑性分析结果表明:按本文方法设计的结构在罕遇地震作用下的屈服模式较为合理,整体结构没有出现薄弱部位,而按现行规范方法设计的结构,收进部位的竖向构件在罕遇地震下较早屈服。
[Abstract]:Step back is building a common irregular type, mainly for skirt roof, facade from Taiwan into the top, into the core barrel and shrink. The previous earthquake damage shows that the receiving site is often in the earthquake destroyed firstly, resulting in the overall seismic capacity of the structure has not yet been adequately because of severe local destroyed and lost the ability to carry around. This vertical step back to high-rise building irregular problems, research focus on the influence of body in reinforced concrete frame structure and frame shear wall structure seismic performance and its control method. The main work and research results are as follows: (1) the continuous method was developed along the highly variable stiffness structure analysis model based on the derivation process considering the effect of axial deformation of column. Compared with finite element model. The results show that the simplified model not only has good calculation accuracy, And high computational efficiency. By using a simplified analysis model of shape into the influence of shear elastic seismic response of frame structure and frame, results show that the degree of size will change into the lateral deformation of the structure continuity and whipping effect. In adjacent locations, the continuity of the lower lateral stiffness ratio and lateral deformation of gamma and there was a significant correlation between the extent of the whiplash effect, suitable for control indicators as a step back. (2) in strict accordance with the current standard of China design a set of frame structure in different degrees and a set of frame structure, the dynamic elasto-plastic analysis on the receiving location adjacent, the relationship between the lower the ratio of lateral stiffness and gamma elasto plastic seismic response of structure, the stiffness degradation, interlaminar deformation, yield model was discussed using gamma as control index of degree of rationality of income. The results show that the stiffness of shear layer The force and displacement ratio between layers, when the frame structure of gamma 1 is less than 0.7, into the position adjacent to the upper layer at the bottom of the column will be earlier yield; stiffness shear and layer displacement angle ratio, when the structure frame 2 gamma is less than 0.9, into the position adjacent to the upper wall at the bottom of the earlier yield. The proposed framework structure should not be less than 0.7 gamma 1, gamma 2 frame shear structure should not be less than 0.9. (3) analyzed the reason of vertical component into position under the action of earthquake early yield, the results showed that the formation of the seismic weak parts and flexural coefficient related redundancy. Therefore, P can be judged according to the seismic weak positions. However, the structure has multiple fortifications, the accuracy of plastic internal force redistribution will affect the judgment results. An improved algorithm is proposed to the component redundancy coefficient, 8 layer and 24 layer frame structure frame structure as an example to verify. Results show that the seismic weak parts of the judgment The dynamic elasto-plastic analysis results. (4) in order to solve the vertical component into parts of the collection under the earthquake early yield problems, puts forward the design method of the seismic performance of the preset yield patterns based on the structure is divided into key components and the energy component. According to the layer stiffness ratio setting key components performance objectives then using energy principle to calculate the energy component of flexural stiffness reduction coefficient, assuming that the key components of flexibility, through, the equivalent linear earthquake response spectrum analysis has been a key component of the seismic bearing capacity demand. By this method and code method are designed into adjacent locations on the lower lateral stiffness ratio is less than the suggested limit value of the frame structure and frame shear structure, dynamic elasto-plastic analysis results show that: according to the structure design of this method in the rare event of yield model under earthquake is more reasonable, the whole body structure No weak parts, and according to the current standard design method of structure, close into parts of the vertical members under rare earthquake early yield.

【学位授予单位】：中国建筑科学研究院
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU973.31

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