L型平面不规则体系的抗震性能分析

发布时间：2018-03-09 09:37

本文选题：超限结构　切入点：L型平面　出处：《沈阳建筑大学》2015年硕士论文　论文类型：学位论文

【摘要】：历次震害表明布置不规则地结构极易发生扭转破坏,其在地震破坏形式中占有很高的比重,在生命财产安全上,给人类带来了不可估量的损失。而在实际工程设计中,为了建筑功能的需要,平面不规则的高层建筑越来越多。多高层不规则结构在水平地震作用下的扭转效应会受到相对偏心距、平扭刚度比、周期比等较多参数影响；我国现行《高层建筑混凝土结构技术规程》中规定7度抗震设防时L型体系l/Bmax不宜大于0.35,但目前城市用地日趋紧张,涌现出很多超限的L型结构。设计者对L型结构在大震作用下的抗震性能比较难把握,有必要补充动力弹塑性分析,加强对L型平面不规则结构扭转效应的研究是十分重要和必要的。本文首先对结构的扭转破坏机理和扭转变形进行分析,对影响结构扭转反应的因素和我国规范中的分析计算方法进行探讨,指出L型平面不规则结构补充弹塑性分析的必要性。然后以沈阳某L型框架剪力墙实际项目为基础,分别进行以下分析：运用PKPM软件中satwe模块分析不同的剪力墙布置方案对结构周期比、位移比、承载力的影响,总结L型框架剪力墙结构剪力墙的布置特点。研究得出加厚或增加两翼边尾部剪力墙可以有效增加抗扭刚度,减小周期比但增加了结构的扭转位移比。以实际模型为基础,建立不同l/Bmax值的系列模型,对比分析不同突出程度对L型框架剪力墙结构的扭转性能和楼板受力状态的影响。l/Bmax值增大,结构的扭转周期比逐渐增大,结构的扭转特性显著加强,结构扭转耦联程度减弱。l/Bmax值对结构的承载力影响不是很明显,对水平构件楼板,l/Bmax值越大,同一位置应力水平越高,但对同一模型的同一应力集中点,基本随楼层数的增加而减小。借助building程序对实际模型进行动力弹塑性分析,就人工波X、Y方向为主方向输入时,对结构进行了详细分析。整体结构在分析过程中满足规范的最低要求且有一定安全储备。L型框架剪力墙结构在突出程度超出规范50%时,仍可以取得良好的抗震效果。但结构部分进入弹塑性阶段后,扭转位移比有所增大,应加以控制。
[Abstract]:The previous earthquake damage shows that the structure with irregular arrangement is prone to torsional damage, which occupies a high proportion in the form of earthquake damage, and brings incalculable losses to human beings in the safety of life and property. However, in the actual engineering design, In order to meet the needs of building function, more and more high-rise buildings with irregular plane will be affected by relative eccentricity, flat torsional stiffness ratio, period ratio and so on. The current Technical Specification for High-rise Building concrete structures stipulates that the L / B max of L-type system should not be greater than 0.35 when the earthquake resistance is 7 degrees, but the urban land use is becoming increasingly tight at present. A lot of L-shaped structures have sprung up. It is difficult for designers to grasp the seismic behavior of L-shaped structures under the action of large earthquakes, so it is necessary to supplement the dynamic elastic-plastic analysis. It is very important and necessary to study the torsional effect of L-shaped plane irregular structures. Firstly, the torsional failure mechanism and torsional deformation of L-shaped irregular structures are analyzed in this paper. The factors affecting the torsional response of structures and the analysis and calculation methods in the code of our country are discussed, and the necessity of supplementary elastoplastic analysis for L-type plane irregular structures is pointed out. The following analyses are carried out respectively: using satwe module in PKPM software to analyze the influence of different layout schemes of shear wall on structure cycle ratio, displacement ratio and bearing capacity, The characteristics of shear wall arrangement in L-type frame shear wall structure are summarized. It is concluded that thickening or increasing the tail shear wall with two wings can increase the torsional stiffness effectively, decrease the period ratio but increase the torsional displacement ratio of the structure. A series of models with different L / B max values are established, and the effects of different outliers on the torsional behavior and floor stress state of L-type frame shear wall structures are compared and analyzed. The torsional cycle ratio of the structures increases gradually, and the torsional characteristics of the structures are significantly strengthened. The degree of torsional coupling of structure is weakened. L / B max has no obvious effect on the bearing capacity of the structure. The larger the value of L / B max of horizontal members is, the higher the stress level is at the same position, but the same stress concentration point of the same model. With the help of building program, the dynamic elastoplastic analysis of the actual model is carried out, when the main direction of the artificial wave XY is input, The structure is analyzed in detail. When the overall structure meets the minimum requirements of the code and has a certain safety reserve. Good seismic effect can still be obtained, but the torsional displacement ratio increases after the structure part enters the elastic-plastic stage, which should be controlled.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU352.11

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