基于修正压力场理论的钢纤维混凝土连梁及剪力墙的抗剪性能研究

发布时间：2018-08-17 16:44

【摘要】：剪力墙结构以优良的抗震性能越来越广泛的应用于高层建筑中。连梁作为联肢剪力墙中墙肢之间的传力纽带,在地震时是剪力墙结构的“第一道防线”,其抗震性能也显得至关重要。为满足建筑使用要求或保证结构的侧向刚度,常常会有跨高比较小的连梁或低矮剪力墙的出现,而这些构件往往出现剪切型破坏的形态,大大削弱了其抗震性能。提高剪力墙及连梁的延性和耗能能力,避免发生脆性剪切破坏,是近几年对剪力墙结构主要的研究方向。钢纤维混凝土因为自身抗拉强度高、变形能力好等优良特性,目前已被用于剪力墙及连梁的研究中,用于提高剪力墙及连梁的抗震性能。已有试验研究表明,连梁和剪力墙中加入钢纤维,可有效的提高构件的承载能力、延性和耗能能力,使其由脆性的剪切破坏向弯曲破坏转变。但是目前对于钢纤维混凝土剪力墙的研究大多集中在试验上,理论分析还不完善,尤其是鉴于抗剪理论的复杂性,对钢纤维混凝土剪力墙抗剪能力的理论分析还十分有限。修正压力场理论考虑了混凝土开裂之后的抗拉能力,能够很好的预测钢筋混凝土构件的抗剪性能,被认为是目前最准确和有效的模型之一。钢纤维混凝土的最大特性就是抗拉强度的提高,因此采用修正压力场理论更能准确的分析钢纤维混凝土构件的抗剪性能。而且修正压力场理论能够计算从开裂到破坏的全部过程,因此能够用于反复荷载下钢纤维混凝土构件的抗剪性能的分析。本文基于修正压力场原理,对钢纤维混凝土连梁及剪力墙的抗剪性能进行了分析,主要研究内容如下：(1)在修正压力场理论的基础上,结合钢纤维混凝土连梁的受力特点,建立了适用于钢纤维混凝土连梁在静力作用下的两种简化截面分析模型。采用这两种分析模型对他人的试验进行了分析,得到的受剪承载力均与试验结果的变异性很小,均可用于钢纤维混凝土连梁的抗剪分析。(2)根据钢纤维混凝土连梁的修正压力场理论模型,通过引入反复荷载下钢纤维混凝土和钢筋的本构关系,建立了反复荷载下钢纤维混凝土连梁截面分析模型。采用该模型对他人的试验进行了对比分析,得到的受剪承载力均与试验结果吻合良好,并结合试验结果,探讨了钢纤维掺量、强度等级以及跨高比等因素对承载力的影响。(3)考虑钢纤维混凝土剪力墙的受力特点,利用修正压力场理论描述剪切特性以及符合平截面假定的弯曲理论描述弯曲特性,建立了钢纤维混凝土剪力墙在低周反复荷载作用下的荷载—位移分析模型。采用该模型对他人的试验进行了分析,绘制了P-△滞回曲线和骨架曲线,分析结果与试验结果吻合良好。
[Abstract]:Shear wall structure is more and more widely used in high-rise buildings with excellent seismic performance. As the force transfer link between the legs of the shear wall, the connecting beam is the "first line of defense" of the shear wall structure during the earthquake, and its seismic performance is also very important. In order to meet the requirements of building use or ensure the lateral stiffness of the structure, there are often connected beams or low shear walls with small span height, and these members often appear shear failure, which greatly weakens their seismic performance. Improving the ductility and energy dissipation capacity of shear walls and beams and avoiding brittle shear failure are the main research directions of shear wall structures in recent years. Steel fiber reinforced concrete (SFRC) has been used in the research of shear walls and beams because of its high tensile strength and good deformation ability, and has been used to improve the seismic performance of shear walls and beams. The experimental results show that the addition of steel fiber into beams and shear walls can effectively improve the bearing capacity, ductility and energy dissipation capacity of members, and make it change from brittle shear failure to bending failure. However, most of the research on steel fiber reinforced concrete shear wall is focused on the test, and the theoretical analysis is not perfect, especially in view of the complexity of shear theory, the theoretical analysis of shear capacity of steel fiber reinforced concrete shear wall is very limited. The modified pressure field theory considers the tensile capacity of concrete after cracking and can predict the shear behavior of reinforced concrete members. It is considered to be one of the most accurate and effective models at present. The most important characteristic of steel fiber reinforced concrete (SFRC) is the improvement of tensile strength, so the modified pressure field theory can be used to analyze the shear behavior of SFRC members more accurately. The modified pressure field theory can calculate the whole process from cracking to failure, so it can be used to analyze the shear behavior of steel fiber reinforced concrete members under repeated loading. Based on the principle of modified pressure field, the shear behavior of steel fiber reinforced concrete connecting beam and shear wall is analyzed in this paper. The main contents are as follows: (1) on the basis of modified pressure field theory, combined with the stress characteristics of steel fiber reinforced concrete connecting beam, Two simplified section analysis models for steel fiber reinforced concrete (SFRC) connected beams under static force are established. Using these two analytical models, the tests of others are analyzed, and the shear capacity obtained is very small with the variation of the test results. It can be used to analyze the shear resistance of steel fiber reinforced concrete beams. (2) according to the modified pressure field theory model of steel fiber reinforced concrete beams, the constitutive relation of steel fiber reinforced concrete and steel bars under repeated loads is introduced. A cross section analysis model of steel fiber reinforced concrete (SFRC) beams under repeated loading is established. The model is used to compare and analyze other people's tests, and the shear capacity obtained is in good agreement with the test results. Combined with the test results, the content of steel fiber is discussed. The influence of strength grade and span height ratio on the bearing capacity. (3) considering the mechanical characteristics of steel fiber reinforced concrete shear wall, the modified pressure field theory is used to describe the shear characteristics and the bending theory, which accords with the assumption of plane section, is used to describe the bending characteristics. The load-displacement analysis model of steel fiber reinforced concrete shear wall under low cyclic loading is established. The P- hysteretic curve and skeleton curve are drawn by using this model. The results are in good agreement with the experimental results.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU973.16

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