基于损伤性能并考虑主余震作用的消能减震结构抗震设计     

刘淼鑫  谭平  魏路 《地震研究》2015,38(3)

综合考虑余震影响和结构损伤,提出一种基于损伤性能的消能减震结构抗震设计方法。为满足结构抵抗余震的性能要求,提出结合主余震的损伤性能目标。以Park-Ang双参数损伤模型为基础建立了结构层间损伤计算公式,通过损伤程度评估结构抗震性能,给出消能减震结构基于损伤性能的抗震设计流程。  相似文献   

主震和余震联合作用下复杂地基上重力坝的稳定性分析     

熊瑜  张林  陈媛  聂鸿博 《岩土力学》2015,36(8):2332-2338

大地震主震发生之后通常伴随强余震,多次余震下大坝的结构损伤破坏累积效应明显。为了解复杂地基上重力坝在主、余地震联合作用下的变形和稳定性,以紧邻汶川地震震中的某大型水利工程重力坝典型坝段A#坝段为研究对象进行研究分析。首先,仅考虑主震作用的影响,采用拟静力法模拟地震主震荷载,运用地质力学模型试验方法,研究主震作用下A#坝段坝与地基的变形特征和模型最终破坏形态;再考虑主、余地震联合作用的影响,采用动力法（即时程分析法）基于ANSYS有限元软件进行计算。研究结果表明,主震作用下模型试验与有限元计算结果基本一致,坝与地基均发生了大变形,且通过模型试验得到了A#坝段最终破坏形态;在主、余地震联合作用下,A#坝段坝与地基的变形的累积增加效应明显,变位特征值比主震作用下明显增大,其坝体最大变形处（坝顶）变位值增幅约为37%,对坝与地基稳定性影响较大。因此,对位于地震高发带复杂地基上的重力坝,应考虑主、余地震联合作用的影响,这样更利于工程的安全。  相似文献   

基于余震序列的地震烈度快速评估方法研究——以青海门源6.9级地震为例          下载免费PDF全文

赵怀群  何少林  陈文凯  司宏俊  尹欣欣  张灿 《地震工程学报》2022,44(2):432-439

地震烈度快速评估产品是破坏性地震发生后应急工作"黑箱期"内研判灾情的重要依据.文章基于青海门源6.9级地震震后2 h内的余震序列,采用最短断层距地震动衰减模型快速评估地震烈度.研究结果显示:利用震后30分钟内的余震序列得到的烈度分布可以初步判定重灾区及灾区范围,但灾区范围略小于实际调查结果;利用1.5 h内的余震序列得...  相似文献   

大地震的重复时间和余震持续时间关系的理论研究          下载免费PDF全文

张国民 《地震地质》1996,18(1):17-24

前人的工作曾给出大地震的强余震活动持续时间与大地震的重复时间之间存在正变化关系，即较长的余震持续时间对应较长的主震复发时间。应用地震孕育的流变模型，推导了大地震重复时间和大震后余震活动持续时间的数学表达式，并从理论上给出了大震重复时间和其余震持续时间之间的对数正比关系，从而为建立大地震的重复时间和余震持续时间的关系提供了一方面理论依据  相似文献   

Regularity and complexity of aftershock occurrence due to mechanical interactions between fault slip and fluid flow   总被引：1，自引：0，他引：1  

Teruo Yamashita 《Geophysical Journal International》2003,152(1):20-33

  相似文献   

The deadliest stable continental region earthquake occurred near Bhuj on 26 January 2001     

B.K. Rastogi  H.K. Gupta  Prantik Mandal  H.V.S. Satyanarayana  M. Kousalya  R. Raghavan  Richa Jain  A.N.S. Sarma  N. Kumar  C. Satyamurty 《Journal of Seismology》2001,5(4):609-615

A large destructive earthquake occurred on 26 January 2001 in the region of Kutch, Gujarat, in Western India, with magnitude Mw 7.7. The earthquake caused very heavy damage and a large number of casualties with more than 20,000 deaths. A preliminary study of ground deformation, damage pattern and aftershock distribution is presented.  相似文献   

噪声水平上的爆炸余震信号提取   总被引：2，自引：0，他引：2  

李学政  杨选辉  胡毓良  雷军 《地震地磁观测与研究》2001,22(1):9-17

文中采用窄带滤波、傅里叶反变换及小波分析在噪声水平上提取弱余震信号。窄带滤波能够在背景噪声水平上以及（－10）－（20）dB记录中提取有用信息，但是往往产生截断误差，如果数字序列具有较大的初始幅值，所提取的波形在截断处发生畸变。傅氏反变换从负信噪比的记录中提取的信号质量较差，伴有高频干扰成分，对于信噪比为正数的记录，傅氏反变换提取的波形是良好的，该种方法同滤波方法一样，也存在截断误差。小波分析从信噪比为负数的记录中提取的信号不理想，而从信噪比为正数的记录中提取的信号质量最好，波形完整，首尾清晰，基线平直，无截断误差。窄带滤波，傅氏反变换及小波分析有两个共同点，基一，都能够从强背景噪声中提取有用信息；其二，信噪比越大，获取的信号质量越高。  相似文献   

A preliminary prediction of seismic damage‐based degradation in RC structures     

Vinay K. Gupta  Sren R. K. Nielsen  Poul H. Kirkegaard 《地震工程与结构动力学》2001,30(7):981-993

Estimation of structural damage from a known increase in the fundamental period of a structure after an earthquake or prediction of degradation of stiffness and strength for a known damage requires reliable correlations between these response functionals. This study proposes a modified Clough–Johnston single‐degree‐of‐freedom oscillator to establish these correlations in the case of a simple elasto‐plastic oscillator. It is assumed that the proposed oscillator closely models the response of a given multi‐degree‐of‐freedom system in its fundamental mode throughout the duration of the excitation. The proposed model considers the yield displacement level and ductility supply ratio‐related parameter as two input parameters which must be estimated over a narrow range of ductility supply ratio from a frequency degradation curve. This curve is to be identified from a set of recorded excitation and response time‐histories. Useful correlations of strength and stiffness degradation with damage have been obtained wherein a simple damage index based on maximum and yield displacements and ductility supply ratio has been considered. As an application, the proposed model has been used to demonstrate that ignoring the effects of aftershocks in the case of impulsive ground motions may lead to unsafe designs. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Spatial distribution of aftershocks and background seismicity in central California     

Mariana Eneva  Gary L. Pavlis 《Pure and Applied Geophysics》1991,137(1-2):35-61

We examine the spatial distribution of earthquake hypocenters in four central California areas: the aftershock zones of the (1) 1984 Morgan Hill (2) 1979 Coyote Lake, and (3) 1983 Coalinga earthquakes, as well as (4) the aseismically creeping area around Hollister. The basic tool we use to analyze these data are frequency distributions of interevent distances between earthquakes. These distributions are evaluated on the basis of their deviation from what would be expected if earthquakes occurred randomly in the study areas. We find that both background seismic activity and aftershocks in the study areas exhibit nonrandom spatial distribution. Two major spatial patterns, clustering at small distances and anomalies at larger distances, are observed depending on tectonic setting. While both patterns are seen in the strike-slip environments along the Calaveras fault (Morgan Hill, Coyote Lake, and Hollister), aftershocks of the Coalinga event (a thrust earthquake) seem to be characterized by clustering only. The spatial distribution of earthquakes in areas gradually decreasing in size does not seem to support the hypothesis of a self-similar distribution over the range of scales studied here, regardless of tectonic setting. Spatial distributions are independent of magnitude for the Coalinga aftershocks, but events in strike-slip environments show increasing clustering with increasing magnitude. Finally, earthquake spatial distributions vary in time showing different patterns before, during, and following the end of aftershock sequences.  相似文献   

Aftershocks hazard in Italy Part I: Estimation of time-magnitude distribution model parameters and computation of probabilities of occurrence     

Barbara Lolli  Paolo Gasperini 《Journal of Seismology》2003,7(2):235-257

We analyzed the available instrumental data on Italian earthquakes from1960 to 1996 to compute the parameters of the time-magnitudedistribution model proposed by Reasenberg and Jones (1989) andcurrently used to make aftershock forecasting in California. From 1981 to1996 we used the recently released Catalogo Strumentale deiTerremoti `Italiani' (CSTI) (Instrumental Catalog Working Group, 2001)joining the data of the Istituto Nazionale di Geofisica e Vulcanologia(INGV) and of the Italian major local seismic network, with magnituderevalued according to Gasperini (2001). From 1960 to 1980 we usedinstead the Progetto Finalizzato Geodinamica (PFG) catalog(Postpischl, 1985) with magnitude corrected to be homogeneous with thefollowing period. About 40 sequences are detected using two differentalgorithms and the results of the modeling for the corresponding ones arecompared. The average values of distribution parameters (p= 0.93±0.21, Log₁₀(c) = –1.53±0.54, b = 0.96±0.18 and a = –1.66±0.72) are in fair agreementwith similar computations performed in other regions of the World. We alsoanalyzed the spatial variation of model parameters that can be used topredict the sequence behavior in the first days of future Italian seismic crisis,before a reliable modeling of the ongoing sequence is available. Moreoversome nomograms to expeditiously estimate probabilities and rates ofaftershock in Italy are also computed.  相似文献