【作者】 何春凯；

【导师】 滕军；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2012， 博士

【摘要】 随着经济的发展,城市化进程的加快,高层建筑所占比例越来越大,地震发生后对高层建筑的损伤评估也显得更加重要。本文从构件尺度、楼层尺度和结构整体尺度对高层钢筋混凝土结构地震损伤评估方法进行了研究。1.本文提出了一种基于楼层加速度监测数据小波包能量分析的高层结构震后损伤模糊评价方法。该方法基于小波变换对结构响应信号变化信息敏感的特点,通过实测楼层加速度信号的小波包分解,获得频带能量变化率指标,然后根据能量变化率与实际损伤的关系对损伤程度进行划分,求得能量变化率指标对不同损伤阶段的模糊评判隶属度,最后利用模糊综合评价方法对楼层和结构整体进行损伤程度评分。利用该方法对一实际工程的振动台模型试验进行损伤评估,所得到的损伤评估结果与实际观察损伤情况基本一致。2.由于数值计算方法在非线性阶段所采用的分析模型的不准确性,造成大震下结构有限元模型计算结果与实际情况可能存在较大偏差。本文提出基于楼层位移修正的高层框架核心筒结构损伤评估方法,利用实测楼层位移对结构有限元模型楼层计算位移进行修正,并对楼层子结构等效线性刚度模型施加修正后的最大层间位移,计算震后损伤状态的刚度下降情况,从而得到楼层尺度的损伤评估结果。在此基础上经加权组合,也可得到整体结构损伤评价结果。分析发现,位移修正系数随结构塑性发展程度的不同而产生相应的变化,而利用剪重比变化率为变量表达位移修正系数与塑性发展的关系较为合理。3.上述小波包能量模糊损伤评估方法和基于位移修正的损伤评估方法均是基于位移信息,从楼层尺度进行损伤评估的。本文通过模型二振动台试验的模型设计和试验工作,对上述两种方法的推广性进行验证。将小波包能量分析模糊评价方法的流程及由模型一总结出的计算参数用于模型二的损伤评估,其结果同样有效,说明利用该方法可以对类似的高层框架核心筒结构地震后的损伤程度进行有效的量化评估。根据基于位移修正的损伤评价方法中利用模型一总结出的以剪重比变化率为变量的位移修正系数计算公式,由模型二的有限元分析结果直接求得位移修正系数,并与由振动台试验得到的位移修正系数相对比,二者之间的偏差在可接受范围之内。说明对于类似形式的高层框架核心筒结构,即使没有安装变形监测系统,也可直接利用有限元分析取得的剪重比变化率求得位移修正系数,并进行损伤评估。4.为实现结构震后损伤评估最终落实到构件层次上,本文从建立有限元模型出发,分析各类构件损伤的特点和分布,提出基于损伤分布系数的构件分类损伤评价方法。该方法根据不同类构件的损伤特点采用相应的损伤计算方法得到各类构件的层损伤值,并从能量的角度出发,研究各类构件震后的损伤分布模式,从而可以由事先建立的有限元计算模型和实际地震动输入,快速得到各类构件的具体损伤分布情况。并根据构件类别的不同得到各自的损伤权重系数,通过各类构件的总体损伤结果加权计算,对结构整体损伤进行评估。该方法的特点是能够得到构件尺度的损伤评估结果,而且适用于未安装变形监测系统的结构。通过模型一的数值模拟结果和试验现象的对比验证,说明该方法是有效的。本文提出的三种高层钢筋混凝土框架核心筒结构地震损伤评价方法,从不同角度、不同尺度对结构进行损伤评估。经验证,这些方法都是有效的,在工程实际中可以根据不同的实际情况进行选择,也可利用几种方法所得结果相互印证。更多还原

【Abstract】 As the development of the economic and the quicker pace of the urbanization, the proportion of the high-rise buildings has become larger and larger. Therefore the damage evaluation for high-rise buildings after the earthquakes becomes even more important. This paper is focus on the study of seismic damage evaluation methods for high-rise reinforced concrete structure on different levels of member scale, storey scale and overall structure scale.1. In this paper, a method of seismic damage fuzzy evaluation for high-rise buildings is proposed, based on the research on wavelet packets of acceleration data measured in storeys. Considering the sensitive of Wavelet Transform to the changes in signals of structural responses, in the proposed method, the signals of acceleration, which are measured in storeys, are processed by wavelet decomposition to obtain the rate indicators of energy changes in frequency band. After that, the indicators are partitioned by the relation between the rate of energy changes and the real damage, to obtain the membership degree of fuzzy evaluation in different damage states. Then the storeys and overall structure are graded on damage by fuzzy comprehensive evaluation method. Using the proposed method, the damage evaluation is applied on the shaking table model test for the practical project-1. The proposed method provides good agreement with the test results. The parameters needed in the proposed method are obtained through the model test.2. Because of the uncertainty in the non-linear constitutive model of materials, which is used in calculation, the results of finite-element analysis of structure under strong earthquakes are probably rather different from the reality. Best on correcting the storey displacements, a damage evaluation method for high-rise frame-core tube structures is proposed in this paper. The storey displacements calculated by finite element analysis are corrected by the measured displacements. The maximum corrected inner-storey displacement is applied on the equivalent linear-stiffness model of sub-structure of storey. Then by calculating the stiffness reduction, the results of damage evaluation on member scale are obtained. The results on overall scale are obtained by weighted combination of the results on member scale. The research shows that the correction coefficient of displacement changes correspondingly with different plastic development state of the structure. A correction coefficient with the rate of shear-weight ratio as variable shows rather reasonable relationship with the plastic development.3. The methods of damage fuzzy evaluation based on wavelet packet energy and damage evaluation based on displacement correction are both depend on the information of displacements, and also both on the storey scale. In this paper, the universality of the both methods are verified through the modeling and shaking table test of practical project-2. On the basis of the damage evaluation methods, which are based on displacement correction, when applying the procedures of fuzzy evaluation based on wavelet packet energy and the displacement correction expression with the rate of shear-weight ratio as variable, in which the calculating parameters are obtained from the practical project-1, to the practical project-2, the displacement correction coefficients obtained by finite element method are acceptable compared with the coefficients measured in the table shaking test. Therefore even without the monitoring system for displacement measurement, the displacement correction coefficient can be obtained by finite element method and then used in damage evaluation.4. The two methods mentioned above are both on storey scale. However, the same storey damage can be related to different types of member damage; therefore solely evaluation on storey scale is not enough. To solve this problem, in this paper, a damage evaluation method on member scale, which is based on the coefficient of damage distribution, is proposed, through the finite element analysis on the damage distribution of all kinds of memebers. In the proposed method, the storey damage coefficients of different members are obtained by each relevant calculating method, according to their own characteristics of damage. Then the pattern of damage distribution after earthquakes is studied from the energy point of view. Therefore the information of damage distribution of different members is obtained quickly by the existed finite element model and the practical seismic motion input. Also the weight coefficients of their own damage are obtained by weighted computation of different kinds of members’total damages, to evaluate the damage of overall structure. The trait of the proposed method is that it can obtain the damage evaluation results on member scale and it is suitable for the structures without deformation monitoring system. The comparison between the test and the results obtained by numerical modeling of the practical project-1 shows that the proposed method is effective.Three methods of seismic damage evaluation for high-rise frame-core tube structure are proposed, to evaluate the damage of structure on different aspects and scales. The proposed methods are verified to be effective. In practical engineering, the proposed methods can be chosen depending on the actual situations, and also the results obtained by three methods can be verified by each other.更多还原