框—剪隔震结构抗扭设计及双随机地震倒塌可靠度研究

发布时间：2018-05-31 14:22

本文选题：平面不规则框-剪结构 + 隔震结构　；参考：《兰州理工大学》2017年博士论文

【摘要】：地震作用下,平面不规则框-剪结构由于质心与刚心不重合,会产生明显的扭转变形,相比于规则结构,可能出现更为严重的破坏,甚至倒塌。因此,本文以层间位移角和层间扭转角为性能指标,提出适用于平面不规则框-剪结构的倒塌易损性分析方法,明确该类结构的抗震性能。在此基础上,提出适用于框-剪隔震结构的抗扭设计方法;利用基于整体地震损伤模型的可靠度分析方法,对框-剪隔震结构侧向增量倒塌、竖向连续倒塌以及侧向连续倒塌可靠度进行分析,本文的主要研究内容如下:1)平面不规则框-剪结构倒塌易损性分析提出适用于平面不规则框-剪结构的倒塌易损性分析方法,利用MATLAB中小波变换系数法,判别地震动的最不利输入角度;考虑量化指标间的相关性及随机性,利用超越概率的计算方法,分别计算层间位移角、层间扭转角及双指标极限状态下的倒塌超越概率。通过对比分析表明,对于平面不规则框-剪结构,地震动输入角度对结构的抗震性能有不可忽略的影响;对平面不规则框-剪结构进行易损性分析时,应同时考虑层间位移角和层间扭转角双指标的影响,防止高估这类结构的抗震性能;基于双指标的易损性分析方法对平面不规则框-剪结构抗震性能的评估更为安全、可靠。2)平面不规则框-剪隔震结构抗扭设计方法提出适用于平面不规则框-剪隔震结构的抗扭设计方法,对不同偏心距的结构进行抗扭设计,通过调整隔震层刚心、上部结构质心和刚心三者之间的相对位置,得到上部结构平面不规则时,隔震结构的抗扭设计方法。研究结果表明,1)对于对称结构或轻微偏心结构,应尽量使上部结构的质心与隔震层的刚心重合,可有效控制隔震层的扭转。2)对于严重偏心结构,应在保证隔震层扭转位移比小于1.2的基础上,使隔震层的刚心和上部结构的刚心分别位于上部结构质心的两侧,可有效控制上部结构的扭转。3)基于多参数的框-剪隔震结构整体地震损伤模型通过引入构件重要性指标,提出考虑构件重要程度且适用于框-剪隔震结构的整体地震损伤模型。研究表明,考虑构件重要程度的整体地震损伤模型,可以同时体现构件塑性累积损伤程度与构件重要程度对整体损伤的影响。利用该损伤模型评估框-剪隔震结构在强震作用下的抗震性能更为安全、可靠。4)框-剪隔震结构地震侧向增量倒塌可靠度分析针对框-剪隔震结构,提出基于整体地震损伤模型的可靠度分析方法。考虑结构及地震动的随机性,采用拉丁超立方体抽样法进行抽样,形成样本空间,对每个样本进行动力弹塑性分析;基于隔震结构整体地震损伤模型,分别计算上部结构和隔震层的累积损伤指数,利用二次四阶矩法对结构地震倒塌极限状态进行抗震可靠度分析,得到地震作用下结构发生侧向增量倒塌的概率。5)框-剪隔震结构地震竖向连续倒塌可靠度分析利用隔震支座的地震损伤模型,得到地震作用下最易失效的隔震支座。在考虑损伤结构随机性的基础上,利用竖向随机增量动力分析方法,得到损伤结构竖向连续倒塌极限荷载系数;将极限荷载系数作为整体性能指标,利用二次四阶矩法得到损伤结构发生竖向连续倒塌的概率。研究表明,运用可靠度理论对框-剪隔震结构进行竖向连续倒塌可靠度分析,可直观地得到地震作用下,损伤框-剪隔震结构发生竖向连续倒塌的概率,为结构设计及震后加固提供可靠的依据。6)主余震序列型地震动作用下框-剪隔震结构连续倒塌可靠度分析对于框-剪隔震结构,地震可能导致隔震支座失效,而损伤结构再次经历余震作用时,可能发生三种失效模式:第一种是由于隔震层失效使结构发生侧向连续倒塌;第二种是由于上部结构失效使结构发生侧向连续倒塌;第三种是受损跨梁失效使结构发生竖向连续倒塌;其倒塌概率与主、余震的地震动强度有关;倒塌模式与隔震支座的失效位置有关。
[Abstract]:Under the action of earthquake, the plane irregular frame shear structure can produce obvious torsional deformation due to the non coincidence of the center of mass and the rigid core. Compared with the regular structure, it may appear more serious damage and even collapse. Therefore, this paper takes the interlayer displacement angle and the interlayer twist angle as the performance index, and puts forward the collapse and vulnerability suitable for the plane irregular frame shear structure. On the basis of this, the anti torsion design method suitable for frame shear isolation structure is proposed, and the reliability analysis method based on the integral seismic damage model is used to analyze the lateral incremental collapse of frame shear isolation structure, the vertical continuous collapse and the lateral collapse reliability. The main research contents are as follows: 1) the analysis of the collapse vulnerability of the plane irregular frame shear structure puts forward the collapse vulnerability analysis method suitable for the plane irregular frame shear structure, and uses the wavelet transform coefficient method in MATLAB to distinguish the most unfavorable input angle of the ground motion, considering the correlation and randomness between the quantized indexes, using the surpassing probability measure. Calculation method, calculation of interlayer displacement angle, interlayer twist angle and double index limit state of collapse surpassing probability respectively. Through comparison and analysis, it is shown that for plane irregular frame shear structure, the seismic input angle of ground motion has not negligible influence on the seismic performance of the structure; when the plane irregularities frame shear structure is vulnerable to vulnerability analysis, it should be at the same time Considering the influence of interlayer displacement angle and interlayer twist angle, the seismic performance of this kind of structure is not overestimated. The double index vulnerability analysis method is more safe and reliable for the seismic performance evaluation of plane irregular frame shear structure. The anti torsional design method of plane irregular frame shear isolation structure is suitable for plane irregular frame -.2. The torsion design method of the shear isolation structure is designed for the torsion design of the structure with different eccentricity. By adjusting the relative position of the rigid center of the isolation layer, the center of the center of mass and the three of the rigid core, the torsion design method of the isolated structure is obtained when the upper structure is irregular. The results show that 1) for the symmetrical structure or the slightly eccentric structure, The centroid of the superstructure should be recombined with the rigid core of the isolation layer as far as possible, and it can effectively control the torsion.2 of the isolation layer. On the basis of ensuring that the torsion displacement ratio of the isolation layer is less than 1.2, the rigid center of the isolation layer and the superstructure are located on both sides of the upper structure centroid respectively, and the torsion of the superstructure can be effectively controlled. .3) the whole seismic damage model of frame shear isolation structure based on multi parameters is introduced by introducing component importance index, and the whole earthquake damage model which considers the importance of component and suitable for frame shear isolation structure is proposed. The study shows that the integral earthquake damage model considering the importance of component can simultaneously reflect the plastic cumulative damage of the component. The impact of degree and component importance on the overall damage. Using the damage model to evaluate the seismic performance of frame shear isolation structure under strong earthquake, the reliability analysis of seismic lateral incremental collapse of frame shear isolation structure is aimed at frame shear isolation structure, and the reliability analysis method based on the whole earthquake damage model is proposed. Considering the randomness of the structure and ground motion, the Latin hypercube sampling method is used to form the sample space, and the dynamic elastoplastic analysis is made for each sample. The cumulative damage index of the superstructure and the isolation layer is calculated based on the whole seismic damage model of the isolation structure, and the collapse limit of the structure is used by the two order four moment moment method. The seismic reliability analysis of the state, the probability of the lateral incremental collapse of the structure under the earthquake action.5) the seismic vertical continuous collapse reliability of the frame shear isolation structure is analyzed using the seismic damage model of the isolation bearing, and the most vulnerable isolation bearing under the earthquake action is obtained. On the basis of considering the randomness of the damage structure, the vertical direction is used. The ultimate load coefficient of the vertical continuous collapse of the damaged structure is obtained by the stochastic incremental dynamic analysis method. The probability of the vertical continuous collapse of the damaged structure by the two order four moment moment method is obtained by using the ultimate load coefficient as a whole performance index. The study shows that the reliability of the frame shear isolation structure is carried out by the reliability theory. The probability of vertical continuous collapse of the damaged frame shear isolation structure can be intuitively analyzed, which provides a reliable basis for structural design and post earthquake reinforcement. The reliability analysis of the continuous collapse of frame shear isolation structure under the action of the main aftershock sequence type ground motion is the frame shear isolation structure, and the earthquake may lead to the failure of the isolation bearing. Three kinds of failure modes may occur when the damage structure is subjected to aftershock again. The first is the lateral collapse of the structure due to the failure of the isolation layer; the second is due to the lateral collapse of the structure caused by the failure of the superstructure; the third is the vertical collapse of the damaged cross beam and the vertical collapse of the structure; the probability of the collapse of the structure is the main collapse probability and the main type. The ground motion intensity is related to the aftershock, and the collapse mode is related to the failure position of the isolation bearing.
【学位授予单位】：兰州理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TU398.2;TU352.12

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