【作者】 余晓峰；

【导师】 姚谦峰；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2009， 博士

【摘要】 密肋复合墙中的内填材料,可因地制宜大量消耗工农业废料,并且自重轻、抗震性能好、节能效果佳,所以是一种理想的建筑结构新体系,有着广泛的推广应用前景。然而将生态材料很好地应用于其新型结构体系,使其成为名符其实的生态节能建筑,目前研究还涉及不足。而再生混凝土是一种“绿色生态”建材。若将其全部或部分替代密肋复合墙中框格和边框中的普通混凝土,不仅可以消化大量的废弃混凝土,扩大再生混凝土的应用范围,而且可以实现密肋复合墙结构的生态化,符合国家的“可持续发展战略”。本文在课题组前期研究成果的基础上,以再生混凝土材料的力学性能和再生混凝土密肋复合墙体的抗震性能为主线；以再生混凝土多轴受力性能试验、再生混凝土密肋复合墙试验和非线性有限元分析为手段；重点围绕再生混凝土多轴本构模型、损伤变量演化规律、墙体的抗震性能和基于再生混凝土强度随机性的有限元概率分析理论与方法,展开了深入系统的研究与探讨。主要内容和创新成果如下：1、采用逐步回归分析建立了再生混凝土强度和影响因素间的数学模型；以强度为目标函数,各个因素取值为约束条件,获得再生混凝土强度的最优配合比。考虑不同影响因素和水平数,设计了混合水平均匀表。分析了不同因素及水平数对再生混凝土基本力学性能的影响；由于各个主要影响因素间的强交互作用,采用逐步回归分析建立了再生混凝土强度与各因素之间的二次多项式数学模型,分析表明：此数学模型的计算精度较好；以强度为目标函数,以各个因素的合理取值为约束条件,利用MATLAB进行优化,最终给出了再生混凝土强度的最优配合比。2、通过再生混凝土常规三轴受压试验,建立了再生混凝土多轴本构模型,并探讨了损伤变量的演化规律。进行了再生混凝土常规三轴受压试验,探讨了再生混凝土在三轴受压下的变形特征；基于试验和连续介质损伤力学理论首次建立了再生混凝土三向受压状态下的多轴本构模型；推导了再生混凝土的三轴割线模量；提出了适宜的损伤变量,并获得在不同围压下损伤变量的演化规律。3、通过不同再生骨料取代率下密肋复合墙体力学和抗震性能试验,揭示了该墙体的受力机理和抗震性能。进行了两榀1／2比例,再生骨料取代率分别为50%和100%的再生混凝土密肋复合墙的水平低周反复试验,系统研究了再生骨料取代率对再生混凝土墙体的破坏过程、破坏特征、承载力、变形、耗能能力及肋柱、肋梁及框柱中钢筋的应力分布,研究了再生混凝土密肋复合墙体的刚度退化规律等,为结构的抗震分析提供了依据。4、建立了再生混凝土密肋复合墙体非线性有限元数值模型。提出了考虑不同再生骨料取代率下密肋复合墙的斜截面承载力公式。应用大型通用有限元软件Ansys,首先对再生混凝土密肋复合墙体在水平和竖向荷载共同作用下的变形、承载力等基本性能进行数值仿真分析,并和试验结果进行了对比。考虑再生骨料取代率的不同水平数及密肋复合墙体斜截面承载力等主要影响因素,建立了再生混凝土密肋复合墙的斜截面承载力公式。5、基于再生混凝土的随机性和有限元概率设计,对不同再生骨料取代率下的再生混凝土复合墙进行了可靠度评价和敏感性分析。考虑再生混凝土材料的随机性,应用Pearson拟合优度法推导了再生混凝土骨料取代率为50%和100%、再生混凝土配置强度分别为C20和C30的概率分布模型和统计参数；基于有限元概率设计和再生混凝土的概率分布模型和统计参数,系统研究了再生混凝土密肋复合墙的承载力在不同再生骨料取代率下的可靠度评价；并分析了再生混凝土密肋复合墙体极限承载力多种影响因素的敏感性。更多还原

【Abstract】 The material of the multi-ribbed composite wall, filled in the gridiron, could consume industrial and agricultural waste with large amount. Meanwhile, the multi-ribbed composite wall structure is a kind of new structural system, which has the light weight, good seismic performance and energy-saving effect. So, the composite wall is a new better structure, which has the good application perspective in the future, and the theoretical and application achievements have been obtained by continuous efforts of research group. However, this point of the multi-ribbed wall, which the new materials use in the new structure, has still lacked. Recycled concrete is the green building materials, which can decrease the exploitation of natural sandrock, can reuse the discarded building waste and fulfils the internal cycle of building materials (building materials-waste-building materials). Now, the common concrete in the frame grid and the side frame of the multi-ribbed composite wall is replaced with the recycled concrete. By mean of those, not only the waste concrete could be reused and expand the application range of recycled concrete, but also the content of green is increased in the multi-ribbed composite wall and alleviate environmental pollution, moreover those coincide with the national requirement of sustainable development.Based on the former research, this paper emphasizes on the mechanical properties, three-dimensional constitutive model, evolution law of damage variables about the recycled concrete and the seismic performance of the recycled concrete multi-ribbed composite wall, the reliability of the structure based on the strength randomness of recycled concrete. The main research contents and achievements are summarized as follows: 1、The mathematic model of the strength and influence factors is built by step regression analysis; The optimum proportions of the recycled concrete strength are achieved by the objective function of strength and the constraint condition of the factors.The strength of recycled concrete (RC), which is influenced by various factors, is researched by the uniform test design. Quadratic function mathematical model for the compressive and splitting tensile strength is achieved by step regression analysis based on the results of experiment. The results show that the quadric mathematical model can describe accurately the inner relationship among the various factors and the RC strength; the mix proportions of RC based on the strengths (compressive resistance and splitting tensile resistance) are optimized, which can instruct the practical engineering.2、For the first time the triaxial compression test of recycled concrete is conducted, and the triaxial constitutive model is built. Moreover, the evolution law of damage variables of recycled concrete is researched.The triaxial compressive test of recycled concrete (RC) is made and the deformation features of recycled concrete are researched under the triaxial compressive. Based on the test and the theory of continuum damage mechanics, the triaxial compressive onstitutive model is suggested about the recycled concrete; the triaxial secant modulus of recycled concrete is deduced and the suitable damage variable is put forward, and acquires the evolution law of damage variable under different confining pressures.3、For the first time the seismic performances test of recycled concrete multi-ribbed composite wall is executed, and the stress mechanism of the wall is researched.Under low-cyclic horizontal loading, two recycled concrete multi-ribbed composite walls (composed of 100%,50%, recycled aggregate) are studied in this paper. The seismic behaviors of recycled concrete multi-ribbed composite wall, such as the failure patterns, hysteretic loop, ductility, deterioration of stiffness and energy dissipation, etc., are researched. Meanwhile, the stress distribution of wall is studied. All those provide the corresponding basis for the use of recycled concrete multi-ribbed composite wall in practice.4、The nonlinear finite element numerical model of the recycled concrete multi-ribbed composite wall is done. By the numerical model, the oblique section formula of recycled concrete wall is established by the first time, with considering the different ratio of the recycled aggregate replacement.Based on the former experiment, the deformation, bearing capacity of the recycled concrete multi-ribbed composite wall is analyzed by Ansys. And by the numerical model that has been proved, the oblique section formula of multi-ribbed composite wall is established, which provides the theoretical foundation.5、Based on the randomness of recycled concrete and the finite element probabilistic design, the reliability evaluation and the sensitivity analysis of the recycled concrete multi-ribbed composite wall are advanced under considering the different ratio of recycled aggregateBased on the predecessor research and by means of mathematical statistics, the probability distribution and statistical parameters of the recycled concrete with various strength and recycled aggregate replacement ratio are given. Based on the finite element probability design, probability distribution and statistical parameters of the recycled concrete, the reliability and the sensitivity of the recycled concrete multi-ribbed composite wall, considering the various factors, is system studied.更多还原