【作者】 于洋；

【导师】 郭迅；

【作者基本信息】 中国地震局工程力学研究所 ， 防灾减灾工程及防护工程， 2010， 博士

【摘要】 配筋砌块砌体结构因其具有节土、节能、环保等特点,在美国、欧洲、日本等发达国家被广泛地应用在建造高层房屋结构中。高层配筋砌块砌体结构的研究及应用在我国则起步较晚,理论体系和试验数据并不很充足。在当前的工程结构抗震研究领域中,其仍为研究的热点之一。论文选取1/4比例10层注芯率为19%的配筋砌块砌体结构为研究对象,在总结前人工作基础上,就配筋砌块砌体结构振动台抗震试验和配筋砌块砌体结构弹塑性数值模拟两个方面进行了研究,主要成果如下:1、确定模型与原型结构的相似关系,按一致相似律设计了目前国内规模最大的配筋混凝土砌块砌体模型结构。模型结构按7度设防,但层数与普通砌体结构相比超过规范3层,构造措施仍按7度要求设置。选择了Northridge、EL Centro-1、EL Centro-2三条地震波,对应从硬到软不同场地,峰值范围从0.06g~0.32g,分别相应7度区多遇烈度、基本烈度及罕遇烈度地震进行试验,沿纵向、横向、纵横向同时共进行了25次地震动输入试验,获取了大量的地震反应记录,考察了模型在各试验阶段的地震反应、变形状态及震害特征。从中筛取了有代表性的数据进行整理分析,为评价结构抗震性能和抗震能力奠定了基础。2、对X方向和Y方向各层输出结果,主要包括卓越频率、模型结构加速度反应、振型、相对位移和应变等记录进行了分析处理。对台面输入与顶层输出卓越频率的关系进行分析,给出回归曲线表达式。对X与Y方向顶层加速度放大系数进行了比较,Y方向平均为2.0,X方向平均为2.7,X方向比Y方向平均高出35%,主要原因是X方向卓越频率比Y方向对应的频率低,所以与台面输入能量富集的频带中心更接近,也就有了更多的共振效应。给出模型结构在两个方向的前三阶振型。对不同地面峰值加速度情况下的相对位移和应变进行时程分析。3、根据加载方案进行试验,对每次试验完成后对模型的开裂情况进行观测。重点观测项目为:开裂部位、裂缝走向、裂缝宽度及结构或构件的破坏情况等。对模型结构进行破坏分析,阐述其破坏机制。对结构震时、震止结构卓越频率的变化规律有一定的认识,对结构振型参数和不同强度地震作用下结构的性态进行了分析。试验现象表明结构能够满足在7度区“小震不坏、中震可修、大震不倒”的要求。4、将X方向考虑为壁式框架、Y方向视为整体剪力墙进行数值分析模型的建立。考虑墙、柱和梁三种构件单元类型,结构单元采用纤维模型。以三参数滞回模型考虑结构构件的滞回关系,充分考虑滞回过程中结构构件的刚度退化、强度退化和捏拢效应。在参考同类文献的基础上,给出了刚度退化参数、强度退化参数和捏拢参数的取值。结构构件破坏能力体系的构建是基于Park&Ang提出的破坏指标。5、应用IDARC5.5程序对模型结构进行了弹塑性地震反应有限元分析,进行了模型结构X、Y两个方向的模态参数及破坏分析,对数值分析结果与试验结果进行了对比。对7度各种加速度峰值作用情况下结构的层间剪力、位移和加速度响应进行分析。对试验结果、数值模拟和规范算法各种情况下的层间剪力进行分析。对模型结构的固有频率变化及破坏指数变化进行了分析。通过分析,给出了现有试验条件下,配筋砌体结构的地震响应情况和不同地震作用情况产生的破坏程度。分析表明适量注芯(19%注芯)的配筋砌体结构有较好的抗震性能,可以满足7度设防标准的要求。综合研究的结果对今后配筋混凝土砌块砌体结构抗震设计规范的修订具有重要参考价值。更多还原

【Abstract】 environmental protection, reinforcement masonry structure is widely used in tall building in developed countries such as the United States, Europe and Japan. The theory system and experimental statistics of the study in this field are not sufficient because of the relatively late starts. Therefore, the study on it is still the focus in the field of engineering structure seismic study. The paper focuses on a 10-stories reinforcement masonry structure, which is in scale of 1/4, and the core casting ratio is 19%, through the anti-seismic test on shaking table as well as elastic and plastic numerical simulation analysis, the following achievement are obtained:1. The test constructs the reinforcement masonry structure model according to the similarity between the model and prototype, and the General Similitude Law as well. The detailing of this model complies with the fortification intensity of VII, but 3 stories beyond the seismic code. Three earthquake records of Northridge、EL Centro-1、EL Centro-2 are selected to input onto the model, corresponding to the different site conditions ranging from hard to soft respectively, applying the records PGA between 0.06g~0.32g, which are equivalent with the frequent intensity, basic intensity and rare intensity. The test inputs 25 records from the direction of X, Y, and X&Y simultaneous, gets massive records of seismic response, analyzes the seismic response, deformation and seismic damage on the model. The typical statistics were organized and analyzed, which set a solid foundation for the seismic evaluation on the building structure.2. Basing on the output records on X-direction and Y-direction, the paper analyzed dominant frequency, accelaration response of model structure, vibration mode, displacement and strain. The expression of regression curve was concluded by analyzing the relation between table input PGA and the dominant frequency of top output. Through comparing the top acceleration amplification factors of X-direction and Y-direction, the average value is 2.7 and 2.0 for X-direction and Y-direction respectively, which is 35% higher than the other. The main reason is that the dominant frequency of X-direction is lower than that of Y-direction, which is similar to the frequency range, therefore, more resonance takes place. The first three vibration modes on both directions are showed in the paper. The paper also analyzes the time history of the relative displacement and the strain under different PGA.3. The experiments are conducted according to the loading plan, and cracked condition is observed carefully. The focuses are as follows: cracked location, crack direction, crack width, the damage behavior of the structure and the element. The paper analyzes the damage condition of the model structure and describes the damage mechanism. By analyzing the experimental statistics, the rule of during and after input predominant frequencies is concluded, and the vibration mode of the structure and structure behavior under different input are analyzed. The appearances in the experiments show that the model meets the requirements as“Perfect subjected to minor earthquake; the maintenance subjected to moderate earthquake; no collapse subjected to unexpected rare earthquake.”4. The numerical analyzing model is constructed as X-direction for wall type frame and Y-direction for shear wall. Considering the elements of shear wall, column and beam, fiber model are applied to general structural elements. Three parameter park model is based while considering the hysteretic rule of the structural elements. The hysteretic rule takes stiffness degradation, strength deterioration and slip into account, which values are referred relative reference. The damage potential system is on the basis of damage index proposed by Park&Ang.5. Using the IDARC5.5 to conduct analysis on the elastic-plastic seismic response of model structure, the paper contrasts the numerical results to experiment findings after studying the model parameter and the damage condition on both X and Y direction. The paper also discusses the story shear force, displacement, acceleration responses under various PGA of fortification intensity of VII. Meanwhile, the values of story shear force are contrast via experimental results, numerical results and calculation results by code method. Moreover, the change of natural frequency and damage index are researched. Through analyzing, seismic response condition and damage extent are concluded under different input. The achievements indicate that reinforcement masonry structure with moderate core casting (19%) meets the requirements of fortification intensity of VII to resist earthquake effectively. The research conclusion has significant value to modify the seismic design code of reinforcement concrete masonry structure.更多还原