RC柱考虑剪切作用的抗震性能和残余变形研究

发布时间：2018-01-16 04:08

本文关键词：RC柱考虑剪切作用的抗震性能和残余变形研究　出处：《大连理工大学》2014年博士论文　论文类型：学位论文

【摘要】：针对地震中许多钢筋混凝土柱、桥墩和桩等压弯构件出现弯剪(或剪切)破坏的现象及我国现行规范中结构(或构件)抗震设计方法不完善的问题,如缺少针对弯剪破坏柱的受力分析模型、未明确给出震后结构性能评估方法及可修复性方面的要求等,本文就不同加载模式下弯剪破坏钢筋混凝土柱的抗震性能退化机理、剪切作用对柱抗震性能影响及柱震后残余变形计算等方面进行了研究,主要包括以下几个方面： 1.对10组(20根)不同剪跨比和配箍率的钢筋混凝土柱试件分别进行单调和低周反复加载试验,研究了两种加载方式对柱地震破坏模式、水平承载力及变形性能等的影响。结果表明,与单调加载相比,反复加载下柱的抗剪承载力和刚度随变形增加退化更明显,易发生以剪切为主的破坏(弯剪破坏或剪切破坏)；柱的变形能力在反复加载下因滞回耗能和损伤累积会产生循环退化效应,且随加载循环次数的增多和位移幅值的增大趋于明显,尤其是在峰值荷载后；基于本文试验结果分析,提出了弯剪破坏钢筋混凝土柱单调荷载-变形曲线与反复荷载滞回曲线包络线之间关系的分析模型。 2.基于本文试验结果,同时考虑弯曲、滑移及剪切变形分量对弯剪破坏钢筋混凝土柱总侧向变形的影响,提出了弯剪破坏柱屈服点、峰值点及破坏点3个受力特征点对应水平荷载和变形的计算模型,并据此提出了弯剪破坏柱荷载-变形关系(曲线)的简化计算方法。 3.基于弯剪破坏钢筋混凝土柱的受力特点,并结合对已有柱抗震性能试验数据的分析,在传统的纤维分析模型(弯曲变形分析模型)和滑移变形分析模型基础上采用修正公式考虑剪切作用影响,提出了适用于地震作用下弯剪破坏柱荷载-变形关系全过程分析的实用方法。 4.基于弯剪破坏钢筋混凝土柱滞回特性及试验结果的分析,建立了弯剪破坏柱等效阻尼比计算模型；利用该模型建立柱地震反应的“需求曲线”,并采用研究内容(3)提出的方法建立柱的“能力曲线”,提出了考虑剪切作用影响的钢筋混凝土柱最大地震位移反应分析方法。 5.基于对多条地震波作用下单自由度(SDOF)体系弹塑性地震响应(最大弹塑性变形和残余变形)的统计分析,研究了自振周期、刚度比、相对屈服力系数、峰值地面加速度及滞回模型对结构地震残余变形的影响；同时结合理论分析,建立了基于概率的钢筋混凝土柱(构件)地震残余变形计算模型。
[Abstract]:Aiming at the phenomenon of bending shear (or shear) failure of many reinforced concrete columns, piers and piles, and the imperfect seismic design methods of structures (or members) in the current code of our country. Such as the lack of bending shear failure column force analysis model, failure to give a clear post-earthquake structural performance evaluation method and repairable requirements and so on. In this paper, the degradation mechanism of seismic behavior of reinforced concrete columns under different loading modes, the effect of shear action on the seismic behavior of columns and the calculation of residual deformation of columns after earthquake are studied. It mainly includes the following aspects: 1. The seismic failure modes of reinforced concrete columns with different shear span ratio and hoop ratio were studied by monotonic and low-cycle repeated loading tests. The results show that the shear capacity and stiffness of the columns under repeated loading are more obvious with the increase of deformation than those under monotonic loading. The main failure is shear failure (bending shear failure or shear failure); The deformation capacity of columns under repeated loading will produce cyclic degradation effect due to hysteretic energy dissipation and damage accumulation, and it tends to be obvious with the increase of loading cycles and displacement amplitude, especially after the peak load. Based on the analysis of the experimental results in this paper, an analytical model of the relationship between the monotone load-deformation curve and the hysteresis curve envelope of bending shear failure reinforced concrete column is proposed. 2. Based on the experimental results in this paper, and considering the effects of bending, slip and shear deformation components on the total lateral deformation of reinforced concrete columns, the yield point of flexural shear failure columns is proposed. Three stress characteristic points of peak point and failure point correspond to the calculation model of horizontal load and deformation, and a simplified calculation method of load-deformation relation (curve) of bending and shear failure column is put forward. 3. Based on the mechanical characteristics of reinforced concrete columns subjected to flexural shear failure, combined with the analysis of seismic performance test data of existing columns. Based on the traditional fiber analysis model (bending deformation analysis model) and slip deformation analysis model, the modified formula is used to consider the effect of shear action. A practical method for the analysis of load-deformation relationship of bending and shear failure columns under earthquake is presented. 4. Based on the analysis of hysteretic characteristics and experimental results of flexural shear failure reinforced concrete columns, the equivalent damping ratio calculation model of flexural shear failure columns is established. The "demand curve" of column seismic response is established by using this model, and the "capacity curve" of column is established by using the method proposed in this paper. A method for maximum seismic displacement response analysis of reinforced concrete columns considering shear effect is presented. 5. Based on the statistical analysis of elastoplastic seismic response (maximum elastic-plastic deformation and residual deformation) of SDOF system, the natural vibration period and stiffness ratio are studied. The influence of relative yield force coefficient, peak ground acceleration and hysteretic model on residual deformation of structures; Based on the theoretical analysis, a probabilistic model for calculating residual deformation of reinforced concrete columns (members) is established.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.3;TU352.11

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