人工气候环境下锈蚀低矮RC剪力墙抗震性能试验研究

发布时间：2018-04-09 16:52

本文选题：低矮RC剪力墙　切入点：人工气候环境　出处：《西安建筑科技大学》2014年硕士论文

【摘要】：底层大空间的建筑在我国具有广泛的应用，而由于底层大空间的使用要求，底层框架的开间和进深一般相对较大，使得底层的抗侧刚度严重削弱，这就要求布置一定数量的低矮RC剪力墙以提高底层框架的抗侧刚度。目前，国内外对低矮RC剪力墙承载力和抗震性能的研究已有较多成果，但是都没有考虑环境因素对其耐久性的影响。在沿海地区，盐雾环境致使RC构件内部钢筋锈蚀，引起了一系列的性能劣化，严重危害结构的可靠性。本文通过对6榀经过不同程度人工气候盐雾腐蚀的低矮RC剪力墙进行低周反复加载试验，研究了人工气候环境下锈蚀低矮RC剪力墙强度、刚度、延性以及耗能能力等抗震性能指标随轴压比和钢筋锈蚀程度变化的退化规律。研究表明：随着轴压比的增加，锈蚀试件的水平承载力提高，刚度变大，延性变差，耗能能力降低；随着设计锈胀裂缝宽度的增大，内部钢筋锈蚀愈发严重，试件的水平承载力下降，刚度退化不断加剧，，延性变差，耗能能力不断降低。确定恢复力模型是结构进行弹塑性地震反应分析的基础，考虑环境因素影响的恢复力模型与完好构件差异明显。本文根据试验数据分析将锈蚀低矮RC剪力墙骨架曲线简化为不考虑下降段的三折线模型，通过拟合得到关于轴压比和横向分布钢筋锈蚀率的骨架曲线特征点计算公式。基于修正的顶点指向型恢复力模型，考虑了刚度和强度退化，给出了正、反卸载刚度及强度退化的计算公式，提出相应的滞回规则，建立了人工气候环境下锈蚀低矮RC剪力墙的恢复力模型。最后给出了绘制计算滞回曲线的步骤，并将计算滞回曲线与试验滞回曲线进行对比分析，结果表明本文所提出的恢复力模型具有较好的适用性，能够准确地描述锈蚀低矮RC剪力墙在反复荷载作用下的恢复力特性。
[Abstract]:The building with large space at the bottom is widely used in our country. However, because of the requirement of the large space of the bottom, the open space and the depth of the bottom frame are relatively large, which makes the lateral stiffness of the bottom layer weaken seriously.This requires a certain number of low RC shear walls to improve the lateral stiffness of the bottom frame.At present, many researches on the bearing capacity and seismic behavior of low RC shear walls have been done at home and abroad, but the effects of environmental factors on their durability have not been taken into account.In coastal areas, the corrosion of steel bars in RC members is caused by salt fog environment, which results in a series of deterioration of performance and seriously endangers the reliability of structures.In this paper, the strength and stiffness of six low RC shear walls corroded by salt spray in artificial climate were studied by repeated low-cycle loading tests, and the strength and stiffness of corroded low RC shear walls in artificial climate were studied.The degradation law of seismic performance indexes such as ductility and energy dissipation capacity changes with axial compression ratio and corrosion degree of steel bar.The results show that with the increase of axial compression ratio, the horizontal bearing capacity, stiffness, ductility and energy dissipation capacity of corroded specimens increase, and the corrosion of internal steel becomes more and more serious with the increase of the width of design corrosion crack.The horizontal bearing capacity of the specimen decreased, the stiffness degradation increased, the ductility became worse and the energy dissipation capacity decreased.The restoring force model is the basis of the elastic-plastic seismic response analysis of the structure. The difference between the restoring force model considering the environmental factors and the intact members is obvious.Based on the analysis of experimental data, the skeleton curve of corroded low RC shear wall is simplified into a three-fold model without considering the descending section, and the characteristic point formula of the skeleton curve for axial compression ratio and transverse distribution corrosion rate of steel bar is obtained by fitting.Based on the modified vertex directed restoring force model, the stiffness and strength degradation are considered, the calculation formulas of positive and reverse unloading stiffness and strength degradation are given, and the corresponding hysteretic rules are proposed.The restoring force model of corroded low RC shear wall in artificial climate is established.Finally, the steps of drawing the calculated hysteretic curve are given, and the calculated hysteretic curve is compared with the experimental hysteretic curve. The results show that the restoring force model proposed in this paper has good applicability.It can accurately describe the restoring force characteristics of corroded low RC shear wall under repeated load.
【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】：2014
【分类号】：TU398.2;TU352.11

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