主余震地震动参数特征及损伤谱研究

发布时间：2018-02-21 08:11

本文关键词： 主余震地震动地震动参数非弹性反应谱潜在破坏势地震动调幅损伤谱　出处：《哈尔滨工业大学》2015年博士论文　论文类型：学位论文

【摘要】：历史地震资料已经表明主震发生之后都伴随着大量余震的发生,主震对结构造成破坏之后,余震通常会进一步增大结构的破坏程度。同时,由于主余震之间的时间间隔较短,主震作用之后已损伤结构无法及时得到维修,这就需要在结构抗震设计及评估中有效合理的考虑余震对结构的危险。然而,目前我国乃至世界的结构抗震设计规范均是针对主震或者单一地震而言,忽略了余震对结构的影响,使得结构在主余震作用下可能无法满足设计要求,进而造成大量不必要的人员伤亡和经济损失。在地震工程中,地震动参数特征的研究以及非弹性反应谱的建立在结构抗震设计中起着重要作用,损伤谱能够综合考虑结构最大变形及滞回耗能对结构破坏的贡献,因而能够更加合理的衡量结构在地震动作用下的损伤。为了能够在结构抗震设计中考虑余震的不利影响,本文针对主余震地震动参数及损伤谱进行了一系列研究。主要研究内容如下:(1)研究了余震地震动参数与主震地震动参数之间的关系,给出了余震地震动的条件预测公式,并与现有的地震动预测公式进行了对比分析,本文提出的余震地震动预测公式与主震参数有关。(2)研究了余震地震动对结构延性系数、残余位移比、标准化滞回耗能和损伤指数的影响,对比分析了不同结构反应指标表征结构附加损伤的能力。结果表明,相比于延性系数,结构滞回耗能和损伤指数能更为有效的反映余震对结构造成的附加损伤。(3)通过余震地震动的相对参数与结构在主余震作用下相对损伤指数之间的相关性,研究了余震地震动的潜在破坏势,分析了结构自振周期、强度折减系数、滞回模型的影响,最后比较了加权平均相关系数的大小,选出了能够反映余震地震动在整个周期段潜在破坏势的参数。结果表明地震动谱加速度能够较好的表征余震地震动对结构的破坏势。(4)通过比较分析地震动调幅前后结构反应指标与地震动调幅指标之间的相关性变化,研究了地震动调幅对结构反应的影响,给出了调幅指标和调幅系数的定量评定。结果表明,余震地震动调幅对结构反应的影响要超过主震地震动,且调幅指标的调幅效果随调幅系数的增大具有更强的随机性;综合而言,地震动谱加速度的调幅效果要优于其他参数。(5)研究了主余震地震动的损伤谱,采用修正的Park-Ang损伤指数、四个滞回模型和大量主余震地震动,通过谱加速度将余震地震动调幅至不同水平,研究了结构自振周期、强度折减系数、场地、余震强度、阻尼、滞回模型及损伤指数系数(β及μu)取值对损伤谱的影响,给出了主余震损伤谱的预测公式,能够方便地应用于结构性态评估。
[Abstract]:Historical seismic data have shown that a large number of aftershocks occur after the occurrence of the main shock. After the main shock causes damage to the structure, the aftershock usually further increases the damage degree of the structure. At the same time, because of the short time interval between the main aftershocks, The damaged structure cannot be repaired in time after the action of the main shock, so it is necessary to consider the danger of aftershock to the structure effectively and reasonably in the seismic design and evaluation of the structure. At present, the codes for seismic design of structures in our country and even in the world are aimed at the main shock or a single earthquake, ignoring the influence of aftershocks on the structure, which makes the structure possibly unable to meet the design requirements under the action of the main aftershock. In seismic engineering, the study of the characteristics of seismic parameters and the establishment of inelastic response spectrum play an important role in the seismic design of structures. The damage spectrum can consider the contribution of the maximum deformation and hysteretic energy to the damage of the structure, so that the damage of the structure under ground motion can be measured more reasonably. In order to consider the adverse effects of aftershocks in the seismic design of the structure, the damage spectrum can be considered. In this paper, a series of studies have been carried out on the ground motion parameters and damage spectrum of the main aftershocks. The main contents are as follows: 1) the relationship between the parameters of the aftershock ground motion and the parameters of the ground motion of the main shock is studied, and the conditional prediction formula of the aftershock ground motion is given. The prediction formula of aftershock ground motion is related to the main shock parameters. The ductility coefficient and residual displacement ratio of aftershock ground motion to structure are studied. The effects of standardized hysteretic energy dissipation and damage index on the ability of different structural response indexes to characterize the additional damage of the structure are compared. The results show that compared with the ductility coefficient, The hysteretic energy dissipation and damage index of structures can reflect the additional damage caused by aftershocks to the structure more effectively. The correlation between the relative parameters of aftershock ground motion and the relative damage index of the structure under the action of the main aftershock can be obtained through the correlation between the relative parameters of the aftershock ground motion and the relative damage index of the structure. In this paper, the potential damage potential of aftershock ground motion is studied, and the influence of natural vibration period, strength reduction coefficient and hysteresis model of the structure is analyzed. Finally, the magnitude of the weighted average correlation coefficient is compared. The parameters which can reflect the potential damage potential of aftershock ground motion in the whole period are selected. The results show that the spectral acceleration of ground motion can better represent the damage potential of aftershock ground motion to the structure. The change of correlation between post-structural response index and amplitude modulation index of ground motion, The influence of amplitude modulation of ground motion on structural response is studied, and the quantitative evaluation of amplitude modulation index and amplitude modulation coefficient is given. The results show that the amplitude modulation of aftershock ground motion has more influence on the structural response than that of the main earthquake ground motion. And the amplitude modulation effect of amplitude modulation index has stronger randomness with the increase of amplitude modulation coefficient, and the amplitude modulation effect of ground motion spectrum acceleration is better than that of other parameters. 5) the damage spectrum of main aftershock ground motion is studied, and the modified Park-Ang damage index is adopted. Four hysteresis models and a large number of major aftershocks are used to modulate the amplitude of aftershock ground motion to different levels through spectral acceleration. The natural vibration period, intensity reduction coefficient, site, aftershock intensity and damping of the structure are studied. The influence of hysteresis model and damage index coefficient (尾 and 渭 u) on the damage spectrum is presented. The prediction formula of the damage spectrum of the main aftershock is given, which can be applied to the evaluation of structural behavior conveniently.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P315.9

【相似文献】