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1.
This paper presents the attenuation relations of peak ground acceleration and spectral accelerations for rock and soil sites in the central and eastern United States (CEUS). For the bedrock site condition, 56 pairs of moment magnitude M and epicentral distance R are used to simulate ground motion, and for each pair of M and R, 550 samples of ground motion parameters are generated using a seismological model together with random vibration theory and distribution of extreme values. From the regression analyses of these data, the attenuation relations of ground motion parameters for the bedrock site are established. With the aid of appropriate site coefficients, these attenuation relations are modified for the site categories specified in the 1994 NEHRP Provisions. These attenuation relations are appropriate for the assessment of seismic hazards at far-field rock and soil sites in the CEUS. 相似文献
2.
2020年10月22日11时03分37秒四川省绵阳市北川县发生MS4.7地震,四川强震动台网与预警烈度速报台网在震区建成较密集的台站,获取了532组三分量加速度记录,有助于开展区域地震动衰减和地震动特征研究.本文对强震记录进行常规处理后计算出强震动记录的相关参数,利用克里金插值方法得到地震动峰值加速度PGA和峰值速度PGV的空间分布图,长轴呈北西—南东方向.分析强震动记录PGA、PGV随距离的衰减规律,与常用衰减关系预测值进行对比,此次地震PGA的衰减特性与俞言祥和汪素云(2006)提出的中国西部地区水平向基岩加速度衰减关系有较好的一致性.北川MS4.7地震获得的密集强震动记录为建立区域衰减关系,以及开展基于经验格林函数方法(EGFM)再现大震强地震动场展布等研究提供了重要的数据支撑. 相似文献
3.
Shi Shuzhong 《中国地震研究》2004,18(2):105-113
Based on intensity data in Shanghai and its adjacent region, the intensity attenuation relation is determined. Selecting the western United States as a reference area where there are rich strong ground motion records and intensity data, and by determining ground motion attenuation relation in an area lacking in strong ground motion data, we obtain the ground motion attenuation relation in Shanghai and its adjacent region. 相似文献
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5.
DISCUSSION ON THE SPECTRA SHAPE OF SEISMIC MARGIN EARTHQUAKE OF NUCLEAR POWER PLANT IN CHINA 
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下载免费PDF全文 Fukushima nuclear accident caused widespread concern of earthquake initiated severe accident. Under this background, China nuclear utilities carried out research and application of seismic margin assessment(SMA)approach to evaluate the seismic margin of the existing nuclear power plants(NPP)by different spectra shape of seismic margin earthquake(SME). By reviewing the method used to determine SME of operational NPP in central and eastern United States(CEUS), this paper analyzed the seismic hazard characteristic of China NPP sites, contrasted the design basis ground motion between NPP in CEUS and China, and suggested giving priority to evaluating the seismic margin of operational NPP that adopted the improved second generation technology for the urgency and importance of assessment on the actual seismic capacity of NPP. Comparing RG1.60 spectrum to normalized site-specific SL-2 level acceleration spectra, we found that some normalized spectra overtook the RG1.60's in high frequency range, so it is not always adequate to scale RG1.60 spectrum to evaluate the seismic margin for sites of the improved second generation NPP. We selected a sample site whose site-specific SL-2 level ground motion is close to the standard design of improved second generation NPP(0.2g scaled RG1.60 spectrum)to determine the seismic margin earthquake by probabilistic seismic hazard analysis method of the sample site. Compared to the given PGA(0.3g)scaled scenario earthquake ground motions and the uniform hazard response spectrum(UHRS), whose PGA is 0.3g to PGA(0.3g)scaled standard spectra(median NUREG/CR0098 spectrum and RG1.60 spectrum), the results demonstrated that uniform hazard response spectrum and scaled scenario earthquake ground motions are both significantly higher than the PGA scaled median NUREG/CR0098 spectrum, and all the three spectra are enveloped by PGA scaled RG1.60 spectrum. Then, this paper suggests adopting the uniform hazard response spectrum or scenario earthquake ground motions to evaluate the seismic margin of improved second generation NPP beyond site SL-2 ground motion; and to evaluate the seismic margin of improved second generation NPP beyond standard design, we recommend to use PGA scaled RG1.60 spectrum. 相似文献
6.
Current codes of practice in assessing the blast ground motion effect on structures are mainly based on the ground peak particle velocity (PPV) or PPV and the principal frequency (PF) of the ground motion. PPV and PF of ground motion from underground explosions are usually estimated by empirical formulae derived from field blast tests. Not many empirical formulae for PF, but many empirical formulae for PPV are available in the literature. They were obtained from recorded data either on ground surface or in the free field (inside the geological medium). Owing to the effect of surface reflection, blast motions on ground surface and in the free field are very different. But not many publications in the open literature discuss the differences of blast motions on ground surface and in the free field. Moreover, very few publications discuss the blast ground motion spatial variation characteristics. As ground motion directly affects structural responses, it is very important to study its characteristics in order to more reliably assess its effects on structures. In this paper, a validated numerical model is used to simulate stress wave at a granite site owing to explosion in an underground chamber. Using the simulated stress wave, the relations such as PPV and PF attenuation as well as spatial variation of motions on ground surface and in the free field are derived. Discussions on the differences of the characteristics of surface and free field motions are made. Results presented in this paper can be used in a more detailed assessment of ground motion effect on structures. 相似文献
7.
The stochastic method for finite faults is applied to simulate the ground motion of the 12 October 1992, m
b
= 5.9, Dahshour earthquake. The method includes discritization of the fault plane into certain number of subfaults, and a
ω-squared spectrum is assigned to each of them. Contributions from all subfaults are then empirically attenuated to the observation
sites, where they are summed to produce the synthetic acceleration time-history. The method is first tested against its ability
of reproducing the recording at Kottamya station. The calibrated model is then applied to calculate the synthetics at a large
number of grid points covering the area around the fault plane. Simulated peak values are subsequently used to produce the
synthetic peak horizontal acceleration map for the area.
We compare the peak horizontal acceleration with the attenuation laws proposed for Egypt as well as the macroseismic intensity
map of the 1992 Dahshour earthquake. The peak horizontal acceleration contours estimated using the calibrated model are mostly
consistent with the observed intensity values and evidences of strong ground motions. Our results encourage the application
of the approach as a supplementary tool for site-specific strong ground motion prediction. 相似文献
8.
Strong ground motions are estimated for the Pacific Northwest assuming that large shallow earthquakes, similar to those experienced in southern Chile, southwestern Japan, and Colombia, may also occur on the Cascadia subduction zone. Fifty-six strong motion recordings for twenty-five subduction earthquakes ofM
s7.0 are used to estimate the response spectra that may result from earthquakesM
w<81/4. Large variations in observed ground motion levels are noted for a given site distance and earthquake magnitude. When compared with motions that have been observed in the western United States, large subduction zone earthquakes produce relatively large ground motions at surprisingly large distances. An earthquake similar to the 22 May 1960 Chilean earthquake (M
w 9.5) is the largest event that is considered to be plausible for the Cascadia subduction zone. This event has a moment which is two orders of magnitude larger than the largest earthquake for which we have strong motion records. The empirical Green's function technique is used to synthesize strong ground motions for such giant earthquakes. Observed teleseismicP-waveforms from giant earthquakes are also modeled using the empirical Green's function technique in order to constrain model parameters. The teleseismic modeling in the period range of 1.0 to 50 sec strongly suggests that fewer Green's functions should be randomly summed than is required to match the long-period moments of giant earthquakes. It appears that a large portion of the moment associated with giant earthquakes occurs at very long periods that are outside the frequency band of interest for strong ground motions. Nevertheless, the occurrence of a giant earthquake in the Pacific Northwest may produce quite strong shaking over a very large region. 相似文献
9.
Multiple-mode surface-wave signals are used to model ground motion at distances of 50 to 500 km for an earthquake source in a continental interior. Motion on a thrust fault is used as the earthquake model. Theoretical ground-motion time histories are generated for this source for various focal depths, receiver azimuths and medium-attenuation models. A shallow source will generate greater values for the ground motion than the same source at a greater depth. Two anelastic attenuation models are considered, one appropriate to the central and eastern United States and the other to southern California. The effects of the difference in the attenuation models are seen at distances greater than 100 km for periods greater than 1.5 sec. 相似文献
10.
This article presents four regional site-specific ground motion relations developed for the state of Himachal Pradesh in northwest Himalaya, situated in a seismically active region. These relations are developed from synthetic free surface ground motion databases obtained from a calibrated stochastic seismological model considering the characteristic properties of this specific region. The adopted methodology incorporates the site effects characterised through active MASW tests conducted in 22 important cities. The estimated ground motion levels from the developed relations are found to be in reasonable agreement with the recorded data. 相似文献
11.
Characterization of Earthquake Strong Ground Motion 总被引：1，自引：0，他引：1
— Some underwater landslides are triggered by strong ground motions caused by earthquakes. This paper reviews current concepts and trends in the characterization of strong ground motion. Improved empirical ground motion models have been derived from a strong motion data set that has grown markedly over the past decade. However, these empirical models have a large degree of uncertainty because the magnitude-distance-soil category parameterization of these models often oversimplifies reality. This reflects the fact that other conditions that are known to have an important influence on strong ground motions, such as near-fault rupture directivity effects, crustal waveguide effects, and basin response effects, are not treated as parameters of these simple models. Numerical ground motion models based on seismological theory that include these additional effects have been developed and extensively validated against recorded ground motions, and used to estimate the ground motions of past earthquakes and predict the ground motions of future scenario earthquakes. 相似文献
12.
ＡｓｔｏｃｈａｓｔｉｃｍｏｄｅｌｏｆｔｈｅＦｏｕｒｉｅｒｐｈａｓｅｏｆｓｔｒｏｎ ｇｒｏｕｎｄｍｏｔｉｏｎＺｈｅｎ－ＰｅｎｇＬＩＡＯ；（廖振鹏）ａｎｄＸｉｎｇＪＩＮ（金星）（ＩｎｓｔｉｔｕｔｅｏｆＥｎｇｉｎｅｅｒｉｎｇＭｅｃｈａｎｉｃｓ，ＳｔａｔｅＳ... 相似文献
13.
The seismological model was developed initially from the fundamental relationship between earthquake ground motion properties and the seismic moment generated at the source of the earthquake. Following two decades of continuous seismological research in the United States, seismological models which realistically account for both the source and path effects on the seismic shear waves have been developed and their accuracy rigorously verified (particularly in the long and medium period ranges). An important finding from the seismological research by Atkinson and Boore and their co‐investigators is the similarity of the average frequency characteristics of seismic waves generated at the source between the seemingly very different seismic environments of Eastern and Western North America (ENA and WNA, respectively). A generic definition of the average source properties of earthquakes has therefore been postulated, referred to herein as the generic source model. Further, the generic ‘hard rock’ crustal model which is characteristic of ENA and the generic ‘rock’ crustal model characteristic of WNA have been developed to combine with the generic source model, hence enabling simulations to be made of the important path‐related modifications to ground motions arising from different types of crustal rock materials. It has been found that the anelastic contribution to whole path attenuation is consistent between the ENA and WNA models, for earthquake ground motions (response spectral velocities and displacements) in the near and medium fields, indicating that differences in the ENA and WNA motions arise principally from the other forms of path‐related modifications, namely the mid‐crust amplification and the combined effect of the upper‐crust amplification and attenuation, both of which are significant only for the generic WNA ‘rock’ earthquake ground motions. This paper aims to demonstrate the effective utilization of the latest seismological model, comprising the generic source and crustal models, to develop a response spectral attenuation model for direct engineering applications. The developed attenuation model also comprises a source factor and several crustal (wave‐path modification) component factors, and thus has also been termed herein the component attenuation model (CAM). Generic attenuation relationships in CAM, which embrace both ENA and WNA conditions, have been developed using stochastic simulations. The crustal classification of a region outside North America can be based upon regional seismological and geological information. CAM is particularly useful for areas where local strong motion data are lacking for satisfactory empirical modelling. In the companion paper entitled ‘response spectrum modelling for rock sites in low and moderate seismicity regions combining velocity, displacement and acceleration predictions’, the CAM procedure has been incorporated into a response spectrum model which can be used to effectively define the seismic hazard of bedrock sites in low and moderate seismicity regions. This paper and the companion paper constitute the basis of a long‐term objective of the authors, to develop and effectively utilize the seismological model for engineering applications worldwide. 相似文献
14.
The characteristics of seismic ground motions in southern China are difficult to determine statistically due to a lack of strong ground motion data. In this study, a stochastic finite-fault ground motion model was adopted to simulate the seismic ground motions at bedrock for southern China, based on parameters derived from small and medium earthquakes that have occurred in the region. From these, the response spectra was estimated. A set of ground motion attenuation relationships was then developed based on simulated peak ground motions and response spectral parameters through regression, which would be applicable for use in engineering practice. Through comparisons, it was demonstrated that the proposed ground motion relationships are generally consistent with those obtained from other reported ground motion attenuation models for southern China. 相似文献
15.
C.-C. P. Tsai 《Pure and Applied Geophysics》1998,152(1):107-123
—The specific barrier model is used for the first time to simulate ground motion accelerations for the purpose of probabilistic seismic hazard analyses at sites near a dominant fault system. It incorporates the simulation of fault geometry and the relationship between the stress drop and seismic moment to estimate the number of cracks on the fault for the specific barrier model. Radiated direct shear waves are established following Boore’s (1983) procedure. The simulated peak ground accelerations (PGA) are then calibrated by strong-motion data. Basically, the model is of uniform source, and the directivity of the source is not taken into consideration. The results show that the calibrated PGA values are not sensitive to the relationship between the stress drop and seismic moment. However, the calibrated PGA values may increase about 20 percent for sites near the fault when the cut-off frequency,?f max?, is raised from 5 Hz to 10 Hz. The variability of the simulated ground motion is, in general, smaller than that of the empirical strong-motion data shown in the literature. This may be improved by adding randomness into the parameter of ?f max and uncertainties into the empirical relationships adopted in the model. The simulated attenuation curves may be used to judge which types of conventional attenuation equations are better at representing the attenuation of PGA for sites near the fault, especially for large earthquake events. 相似文献
16.
17.
Key elements of regional seismic velocity models for long period ground motion simulations 总被引：1，自引：0，他引：1
Thomas M. Brocher 《Journal of Seismology》2008,12(2):217-221
Regional 3-D seismic velocity models used for broadband strong motion simulations must include compressional-wave velocity
(Vp), shear-wave velocity (Vs), intrinsic attenuation (Qp, Qs), and density. Vs and Qs are the most important of these parameters
because the strongest ground motions are generated chiefly by shear- and surface-wave arrivals. Because Vp data are more common
than Vs data, many researchers first develop a Vp model and convert it to a Vs model. I describe recent empirical relations
between Vs, Vp, Qs, Qp, and density that allow velocity models to be rapidly and accurately calculated.
The U. S. government reserves the right to retain a non-exclusive, royalty free license in and to any copyright. 相似文献
18.
Because of low absorption of seismic wave energy in the central United States, as compared to the western part, relations between ground motion and intensity differ for the two regions. This paper presents some empirical relations between magnitude, intensity and perceptibility that are applicable to the central United States. In general, the areas of perceptibility and of damage are one to two orders greater for earthquakes in the central area than for western earthquakes of equal magnitude or of equal maximum Modified Mercalli intensity. 相似文献
19.
Seismic ground motion relationship in southern China based on stochastic finite-fault model 总被引：1，自引：0，他引：1
The characteristics of seismic ground motions in southern China are difficult to determine statistically due to a lack of strong ground motion data. In this study, a stochastic finite-fault ground motion model was adopted to simulate the seismic ground motions at bedrock for southern China, based on parameters derived from small and medium earthquakes that have occurred in the region. From these, the response spectra was estimated. A set of ground motion attenuation relations hipswas then developed based on simulated peak ground motions and response spectral parameters through regression, which would be applicable for use in engineering practice. Through comparisons, it was demonstrated that the proposed ground motion relationships are generally consistent with those obtained from other reported ground motion attenuation models for southern China. 相似文献
20.
中强地震活动区地震动衰减关系的确定 总被引：3，自引：0，他引：3
地震动衰减关系是影响地震安全性评价特别是地震区划结果的重要因素.我国现行的地震动衰减关系主要是依据6级以上地震的地面运动资料得到的,并没有考虑中强地震的衰减特性.为此,文中利用现有的烈度资料和其他可供参考的研究成果来建立我国中强地震活动区的地震动衰减关系.收集了我国华中、华南、东北等地区的51次地震的烈度等震线资料,运用单随机变量加权最小二乘回归法得到中强地震活动区烈度衰减关系.然后以美国西部地区为参考地区,运用缺乏地震动参数的地震动估计方法-地震对映射法得到中强地震活动区峰值加速度和有效峰值加速度衰减关系.最后,通过与我国强地震区和中强地震区已有的烈度衰减关系和地震动衰减关系的对比,验证了得出的我国中强地震活动区烈度衰减关系和地震动衰减关系的合理性. 相似文献