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1.
《Geomechanics and Geoengineering》2013,8(1):57-68
Both seismic and tsunami hazards design criteria are essential input to the rehabilitation and long-term development of city of Banda Aceh Post Sumatra 2004 (M w=9.3) disaster. A case study to develop design criteria for future disaster mitigation of the area is presented. The pilot study consists of probabilistic seismic and tsunami hazard analysis. Results of the probabilistic seismic hazard analysis indicates that peak ground acceleration at baserock for 10 and 2% probability of exceedance in 50 years is 0.3 and 0.55 g, respectively. The analysis also provides spectral values at short (T=0.2 s) and long period (T=1.0 s) motions. Some non-linear time-domain earthquake response analyses for soft, medium, and hard site-class were conducted to recommend design response spectra for each site-class. In addition, tsunami inundation maps generated from probabilistic tsunami hazard analysis were developed through tsunami wave propagation analysis and run-up numerical modeling associated with its probability of tsunamigenic earthquake source potential. Both the seismic and tsunami hazard curve and design criteria are recommended as contribution of this study for design criteria, as part of the disaster mitigation effort in the development process of the city. The methodology developed herein could be applied to other seismic and tsunami disaster potential areas. 相似文献
2.
《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2013,7(3-4):173-185
The most important seismic hazard parameters required to demarcate seismic zones are the peak horizontal acceleration (PHA) and spectral acceleration (SA). The two approaches for evaluation of seismic hazard are the probabilistic seismic hazard analysis and the deterministic seismic hazard analysis (DSHA). The present study evaluates the seismic hazard of the South Indian Peninsular region based on the DSHA methodology. In order to consider the epistemic uncertainties in a better manner, a logic tree approach was adopted in the evaluation of seismic hazard. Two types of seismic sources and three different attenuation relations were used in the analysis. The spatial variation of PHA (mean and 84th percentile values) and SA values for 1 Hz and 10 Hz at bedrock level (84th percentile values) for the entire study area were evaluated and the results are presented here. The surface level peak ground acceleration (PGA) values will be different from that of the bedrock level values due to the local site conditions. The PGA values at ground surface level were evaluated for four different National Earthquake Hazard Reduction Program site classes by considering the non-linear site response of different soil types. The response spectra for important cities in South India were also prepared using the deterministic approach and the results are presented in this paper. 相似文献
3.
香港地区地震风险评价和设防区划 总被引：3，自引：0，他引：3
香港地区隶属于中国板内地震区中的东南沿海块缘地震带。港-九块体为晚中生代至早第三纪以来以持续稳定上升为主的块体, 块体活动性明显地低于其周边相对下沉的中新生代盆地。为此, 赋予港-九块体为最大可信震级M=5.5级潜在震源区, 而其周边中新生代断陷盆地则为最大可信震级M6.0潜在震源。从大陆地震构造成因的环境、潜在震源可信震级范围M=5.0～7.5和近源地震动饱和等三个方面的可比性, 结合中国大陆地震震源破裂尺度和地震烈度影响场, 所建立的反映中国地震构造和震源破裂及地震烈度影响场特点的PGA和反应谱地震动衰减预测关系式可用于香港地区。以50%概率时的中值对中国强震记录的对比, 本研究所提供的经验期望预测关系式, 能包络实际的资料。因此, 用此地震动衰减预测模式对香港地区地震危险性进行评估, 将会得到相对保守地震动预测值。通过香港地区基岩地震动危险性分析和计算, 参照中国大陆地震设防标准, 进行了基岩设计参数确定和区划。以年概率P=0.02、P=0.002、P=0.0004三个概率标准, 对应的地震动重复周期大约分别约为50a, 500a, 2500a的基岩PGA和反应谱, 作为香港地区基岩上构筑物和建筑物可选的基 相似文献
4.
Probabilistic seismic hazard of Pakistan, Azad-Jammu and Kashmir 总被引：2，自引：2，他引：0
The seismic hazard study for Pakistan and Azad Jammu and Kashmir has been conducted by using probabilistic approach in terms
of peak ground acceleration (PGA) in m/s2 and also seismic hazard response spectra for different cities. A new version of Ambraseys et al. (Bull Earthq Eng 3:1–53,
2005) ground acceleration model is used, and parameterization is based on most recent updated earthquake catalogs that consisted
of 14,000 events. The threshold magnitude was fixed at M
w 4.8, but seismic zones like northern Pakistan–Tajikistan, Hindukush and northern Afghanistan–Tajikistan border had M
w 5.2. The average normalized ‘a’ and ‘b’ values for all zones are 6.15 and 0.95, respectively. Seismicity of study area was modeled, and ground motion was computed
for eight frequencies (0.025, 0.1, 0.2, 0.5, 1.0, 1.5, 2.0, 2.5 s) for different annual exceedance rates of 0.02, 0.01, 0.005,
0.002 and 0.001 (return periods 50, 100, 200, 500 and 1,000 years) for stiff rocks at the gridding of 0.1° × 0.1°. Seismic
hazard maps based on computed PGA for 0.02, 0.01 and 0.002 annual exceedance are prepared. These maps indicate the earthquake
hazard of Pakistan and surrounding areas in the form of acceleration contour lines, which are in agreement with geological
and seismotectonic characteristics of the study area. The maximum seismic hazard values are found at Muzaffarabad, Gilgit
and Quetta areas. 相似文献
5.
6.
Shafiee Ali Kamalian Mohsen Jafari Mohammad Kazem Hamzehloo Hossein 《Natural Hazards》2011,59(1):481-505
An important step in effectively reducing seismic risk and the vulnerability of a city located in an earthquake prone area
is to conduct a ground motion microzonation study for the desired return period. The International Institute of Earthquake
Engineering and Seismology (IIEES) initiated a number of seismic microzonation projects for Iran. This paper presents the
steps followed by IIEES in ground motion microzonation. IIEES performs both probabilistic and deterministic seismic hazard
analysis. IIEES uses his own fault map for seismotectonic studies and develops modulus and damping curves for the soils in
the study area. The experience of ground motion microzonation shows that in almost all cases, the estimated 475-year peak
ground acceleration (PGA) values are higher than the PGA proposed by the Iranian seismic code. Although ground motion microzonation
in Iran has some shortcomings, IIEES is making new improvement. This includes development in deterministic seismic hazard
analysis, two-dimensional and three-dimensional modelling of basin and topographical effects, using microtremor measurements
to find shear-wave velocity profiles in high-density urban areas and providing maps for spectral acceleration in the study
area. 相似文献
7.
It has been known that ground motion amplitude will be amplified at mountaintops; however, such topographic effects are not
included in conventional landslide hazard models. In this study, a modified procedure that considers the topographic effects
is proposed to analyze the seismic landslide hazard. The topographic effect is estimated by back analysis. First, a 3D dynamic
numerical model with irregular topography is constructed. The theoretical topographic amplification factors are derived from
the dynamic numerical model. The ground motion record is regarded as the reference motion in the plane area. By combining
the topographic amplification factors with the reference motions, the amplified acceleration time history and amplified seismic
intensity parameters are obtained. Newmark’s displacement model is chosen to perform the seismic landslide hazard analysis.
By combining the regression equation and the seismic parameter of peak ground acceleration and Arias intensity, the Newmark’s
displacement distribution is generated. Subsequently, the calculated Newmark’s displacement maps are transformed to the hazard
maps. The landslide hazard maps of the 99 Peaks region, Central Taiwan are evaluated. The actual landslide inventory maps
triggered by the 21 September 1999, Chi-Chi earthquake are compared with the calculated hazard maps. Relative to the conventional
procedure, the results show that the proposed procedures, which include the topographic effect can obtain a better result
for seismic landslide hazard analysis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
The objective of this study is to evaluate the seismic hazard at the Esfarayen-Bojnurd railway using the probabilistic seismic hazard assessment (PSHA) method. This method was carried out based on a recent data set to take into account the historic seismicity and updated instrumental seismicity. A homogenous earthquake catalogue was compiled and a proposed seismic sources model was presented. Attenuation equations that recently recommended by experts and developed based upon earthquake data obtained from tectonic environments similar to those in and around the studied area were weighted and used for assessment of seismic hazard in the frame of logic tree approach. Considering a grid of 1.2 × 1.2 km covering the study area, ground acceleration for every node was calculated. Hazard maps at bedrock conditions were produced for peak ground acceleration, in addition to return periods of 74, 475 and 2475 years. 相似文献
9.
《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》1999,24(6):523-528
We present a method for estimating the seismic intensity in terms of MMI or MSK scale using Fourier amplitude spectra of ground acceleration. The method implies that severity of earthquake ground motion is determined by spectral amplitudes in relatively narrow frequency band: so-called “representative frequencies”, at decreasing frequencies (from 7–8 Hz for small intensities to 0.7 – 1.0 Hz for MMI(MSK) = VIII–IX) with increasing intensity level. It is examined through estimation of probable intensity at a site using recordings of recent earthquakes in several seismic regions and prediction of intensity distribution patterns for some earthquakes. Seismic hazard maps, in terms of intensity levels based upon the proposed approach, should describe regional features of seismic waves excitation and propagation, as well as local ground conditions. 相似文献
10.
The state of Chiapas (SE México) conforms a territory of complex tectonics and high seismic activity. The interaction among the Cocos, North American and Caribbean tectonic plates, as well as the active crustal deformation inside Chiapas, determines a variety of seismogenic sources of distinct characteristics and particular strong ground motion attenuation. This situation makes the assessment of seismic hazard in the region a challenging task. In this work, we follow the methodology of probabilistic seismic hazard analysis, starting from the compilation of an earthquake catalogue, and the definition of seismogenic source-zones based on the particular seismotectonics of the region: plate-subduction-related sources (interface and intraslab zones), active crustal deformation zones and the shear zone between the North American and Caribbean plates formed by the Motagua, Polochic and Ixcán faults. The latter source is modelled in two different configurations: one single source-zone and three distinct ones. We select three ground motion prediction equations (GMPEs) recommended for South and Central America, plus two Mexican ones. We combine the GMPEs with the source-zone models in a logic tree scheme and produce hazard maps in terms of peak ground acceleration and spectral acceleration for the 500-, 1000- and 2500-year return periods, as well as uniform hazard spectra for the towns of Tuxtla Gutiérrez, Tapachula and San Cristóbal. We obtain higher values in comparison with previous seismic hazard studies and particularly much higher than the output of the Prodisis v.2.3 software for seismic design in México. Our results are consistent with those of neighbouring Guatemala obtained in a recent study for Central America.
相似文献11.
Economic importance of major ports is well known, and if ports are located in seismically active regions, then site-specific
seismic hazard studies are essential to mitigate the seismic risk of the ports. Seismic design of port sites and related structures
can be accomplished in three steps that include assessment of regional seismicity, geotechnical hazards, and soil structure
interaction analysis. In the present study, site-specific probabilistic seismic hazard analysis is performed to identify the
seismic hazard associated with four typical port sites of Gujarat state (bounded by 20°–25.5°N and 68°–75°E) of India viz.
Kandla, Mundra, Hazira, and Dahej ports. The primary aim of the study is to develop consistent seismic ground motion for the
structures within the four port sites for different three levels of ground shaking, i.e., operating level earthquake (72 years
return period), contingency level earthquake (CLE) (475 year return period), and maximum considered earthquake (2,475 year
return period). The geotechnical characterization for each port site is carried out using available geotechnical data. Shear
wave velocities of the soil profile are estimated from SPT blow counts using various empirical formulae. Seismicity of the
Gujarat region is modeled through delineating the 40 fault sources based on the seismotectonic setting. The Gujarat state
is divided into three regions, i.e., Kachchh, Saurashtra, and Mainland Gujarat, and regional recurrence relations are assigned
in the form of Gutenberg-Richter parameters in order to calculate seismic hazard associated with each port site. The horizontal
component of ground acceleration for three levels of ground shaking is estimated by using different ground motion attenuation
relations (GMAR) including one country-specific GMAR for Peninsular India. Uncertainty in seismic hazard computations is handled
by using logic tree approach to develop uniform hazard spectra for 5% damping which are consistent with the specified three
levels of ground shaking. Using recorded acceleration time history of Bhuj 2001 earthquake as the input time motion, synthetic
time histories are generated to match the developed designed response spectra to study site-specific responses of port sites
during different levels of ground shaking. It is observed that the Mundra and Kandla port sites are most vulnerable sites
for seismic hazard as estimated CLE ground motion is in order of 0.79 and 0.48 g for Mundra and Kandla port sites, respectively.
Hazira and Dahej port sites have comparatively less hazard with estimated CLE ground motion of 0.17 and 0.11 g, respectively.
The ground amplification factor is observed at all sites which ranges from 1.3 to 2.0 for the frequency range of 1.0–2.7 Hz.
The obtained spectral accelerations for the three levels of ground motions and obtained transfer functions for each port sites
are compared with provisions made in Indian seismic code IS:1893-Part 1 (2002). The outcome of present study is recommended for further performance-based design to evaluate the seismic response of the
port structures with respect to various performance levels. 相似文献
12.
The performance-based liquefaction potential analysis was carried out in the present study to estimate the liquefaction return
period for Bangalore, India, through a probabilistic approach. In this approach, the entire range of peak ground acceleration
(PGA) and earthquake magnitudes was used in the evaluation of liquefaction return period. The seismic hazard analysis for
the study area was done using probabilistic approach to evaluate the peak horizontal acceleration at bed rock level. Based
on the results of the multichannel analysis of surface wave, it was found that the study area belonged to site class D. The
PGA values for the study area were evaluated for site class D by considering the local site effects. The soil resistance for
the study area was characterized using the standard penetration test (SPT) values obtained from 450 boreholes. These SPT data
along with the PGA values obtained from the probabilistic seismic hazard analysis were used to evaluate the liquefaction return
period for the study area. The contour plot showing the spatial variation of factor of safety against liquefaction and the
corrected SPT values required for preventing liquefaction for a return period of 475 years at depths of 3 and 6 m are presented
in this paper. The entire process of liquefaction potential evaluation, starting from collection of earthquake data, identifying
the seismic sources, evaluation of seismic hazard and the assessment of liquefaction return period were carried out, and the
entire analysis was done based on the probabilistic approach. 相似文献
13.
Mahmoud Hamlaoui K. Vanneste K. Baddari L. Louail B. Vleminckx A. Demdoum 《Arabian Journal of Geosciences》2017,10(11):238
This work involves updating the evaluation of seismic hazard in Northeast Algeria by a probabilistic approach. This reassessment attempts to resolve inconsistencies between seismic zoning in regional building codes and is further motivated by the need to refine the input data that are used to evaluate seismic hazard scenarios. We adopted a seismotectonic model that accounts for differences in interpretations of regional seismicity. We then performed a probabilistic assessment of regional seismic hazard in Northeast Algeria. Based on a homogeneous earthquake catalog and geological and seismotectonic data gathered in the first part of the study, a seismotectonic zoning map was created and seven risk areas were identified. For each area, peak ground acceleration hazard maps were produced. Details of the calculations are provided, including hazard curves at periods of 0.1, 0.2, 0.33, 0.5, 1.0, and 2.0 s and uniform hazard spectra at urban locations in the area, including Sétif, Constantine, Kherrata, Bejaia, and Jijel. 相似文献
14.
Nadia Tahernia Morteza Khodabin Noorbakhsh Mirzaei 《Arabian Journal of Geosciences》2014,7(8):3259-3269
The development of the new seismic hazard map of metropolitan Tehran is based on probabilistic seismic hazard computation using the non-Poisson recurrence time model. For this model, two maps have been prepared to indicate the earthquake hazard of the region in the form of iso-acceleration contour lines. They display the non-Poisson probabilistic estimates of peak ground accelerations over bedrock for 10 and 63 % probability of exceedance in 50 years. To carry out the non-Poisson seismic hazard analysis, appropriate distributions of interoccurrence times of earthquakes were used for the seismotectonic provinces which the study region is located and then the renewal process was applied. In order to calculate the seismic hazard for different return periods in the probabilistic procedure, the study area encompassed by the 49.5–54.5°E longitudes and 34–37°N latitudes was divided into 0.1° intervals generating 1,350 grid points. PGA values for this region are estimated to be 0.30–0.32 and 0.16–0.17 g for 10 and 63 % probability of exceedance, respectively, in 50 years for bedrock condition. 相似文献
15.
Probabilistic seismic hazard analysis of interconnected infrastructure: a case of Iranian high-pressure gas supply system 总被引：2，自引：1，他引：1
A. Golara 《Natural Hazards》2014,73(2):567-577
Seismic hazard maps are widely used for engineering design, land-use planning, and disaster mitigation. The development of the new seismic hazard map of Iran with regard to the specification of Iranian high-pressure gas network is based on probabilistic seismic hazard analysis using the historical and new earthquakes data, geology, tectonics, fault activity, and seismic zone models in Iran. The map displays the probabilistic estimates of peak ground acceleration for the return period of 2,475 year (2 % probability in 50 years). The results presented in this study will provide the basis for the preparation of risk map, the estimation of insurance premiums, finding best paths for future pipelines, planning, and relocating lifeline facilities especially for interconnected infrastructures. 相似文献
16.
Probabilistic seismic hazard analysis for Sumatra, Indonesia and across the Southern Malaysian Peninsula 总被引：1，自引：0，他引：1
Mark D. Petersen James Dewey Stephan Hartzell Charles Mueller Stephan Harmsen ArthurD. Frankel Ken Rukstales 《Tectonophysics》2004,390(1-4):141-158
The ground motion hazard for Sumatra and the Malaysian peninsula is calculated in a probabilistic framework, using procedures developed for the US National Seismic Hazard Maps. We constructed regional earthquake source models and used standard published and modified attenuation equations to calculate peak ground acceleration at 2% and 10% probability of exceedance in 50 years for rock site conditions. We developed or modified earthquake catalogs and declustered these catalogs to include only independent earthquakes. The resulting catalogs were used to define four source zones that characterize earthquakes in four tectonic environments: subduction zone interface earthquakes, subduction zone deep intraslab earthquakes, strike-slip transform earthquakes, and intraplate earthquakes. The recurrence rates and sizes of historical earthquakes on known faults and across zones were also determined from this modified catalog. In addition to the source zones, our seismic source model considers two major faults that are known historically to generate large earthquakes: the Sumatran subduction zone and the Sumatran transform fault. Several published studies were used to describe earthquakes along these faults during historical and pre-historical time, as well as to identify segmentation models of faults. Peak horizontal ground accelerations were calculated using ground motion prediction relations that were developed from seismic data obtained from the crustal interplate environment, crustal intraplate environment, along the subduction zone interface, and from deep intraslab earthquakes. Most of these relations, however, have not been developed for large distances that are needed for calculating the hazard across the Malaysian peninsula, and none were developed for earthquake ground motions generated in an interplate tectonic environment that are propagated into an intraplate tectonic environment. For the interplate and intraplate crustal earthquakes, we have applied ground-motion prediction relations that are consistent with California (interplate) and India (intraplate) strong motion data that we collected for distances beyond 200 km. For the subduction zone equations, we recognized that the published relationships at large distances were not consistent with global earthquake data that we collected and modified the relations to be compatible with the global subduction zone ground motions. In this analysis, we have used alternative source and attenuation models and weighted them to account for our uncertainty in which model is most appropriate for Sumatra or for the Malaysian peninsula. The resulting peak horizontal ground accelerations for 2% probability of exceedance in 50 years range from over 100% g to about 10% g across Sumatra and generally less than 20% g across most of the Malaysian peninsula. The ground motions at 10% probability of exceedance in 50 years are typically about 60% of the ground motions derived for a hazard level at 2% probability of exceedance in 50 years. The largest contributors to hazard are from the Sumatran faults. 相似文献
17.
This article presents probabilistic seismic hazard analyses of northern Pakistan region carried out to produce macro-seismic hazard maps for the region that define new regional ground motion design parameters for 95-, 475-, 975- and 2475-year return period earthquakes as regional contour maps and horizontal uniform hazard at important cities. The Cornell–McGuire approach (Cornell in Bull Seismol Soc Am 58(05):1583–1606, 1968; McGuire in FORTRAN computer program for seismic risk analysis. US Geological Survey, Open file Report, 76-6768, 1976) is used to carry out the analyses at 0.1° rectangular grid. The seismotectonic model of the region used in analysis consists of shallow and deep area zones differentiated based on the focal depths of the earthquakes. Earthquake catalogue compiled and used in the analysis is a composite catalogue composed of 19,373 events. Ground motion prediction equations (GMPEs) used are calibrated using goodness-of-fitness measures and visual inspection with local strong motion data. Epistemic uncertainty in the GMPEs is taken into account through the logic tree approach. Comparison of ground motions due to deep earthquakes is made for the first time for the region. The comparison between ground motion due to shallow and deep earthquakes indicates that the seismic hazard would be underestimated if the deep earthquakes are excluded. Ground motion values obtained in this study considering all the earthquakes suggest ground motions are dominant towards the north east of the region. The proposed study indicates that the ground motion hazard values suggested by the current Building Code of Pakistan underestimate the seismic hazard. Final results of this study are in close agreement with the recent studies on the region. 相似文献
18.
Probabilistic seismic hazard maps for the sultanate of Oman 总被引：2，自引：0，他引：2
I. El-Hussain A. Deif K. Al-Jabri N. Toksoz S. El-Hady S. Al-Hashmi K. Al-Toubi Y. Al-Shijbi M. Al-Saifi S. Kuleli 《Natural Hazards》2012,64(1):173-210
This study presents the results of the first probabilistic seismic hazard assessment (PSHA) in the framework of logic tree for Oman. The earthquake catalogue was homogenized, declustered, and used to define seismotectonic source model that characterizes the seismicity of Oman. Two seismic source models were used in the current study; the first consists of 26 seismic source zones, while the second is expressing the alternative view that seismicity is uniform along the entire Makran and Zagros zones. The recurrence parameters for all the seismogenic zones were determined using the doubly bounded exponential distribution except the zones of Makran, which were modelled using the characteristic distribution. Maximum earthquakes were determined and the horizontal ground accelerations in terms of geometric mean were calculated using ground-motion prediction relationships developed based upon seismic data obtained from active tectonic environments similar to those surrounding Oman. The alternative seismotectonic source models, maximum magnitude, and ground-motion prediction relationships were weighted and used to account for the epistemic uncertainty. Hazard maps at rock sites were produced for 5?% damped spectral acceleration (SA) values at 0.1, 0.2, 0.3, 1.0 and 2.0?s spectral periods as well as peak ground acceleration (PGA) for return periods of 475 and 2,475?years. The highest hazard is found in Khasab City with maximum SA at 0.2?s spectral period reaching 243 and 397?cm/s2 for return periods 475 and 2,475 years, respectively. The sensitivity analysis reveals that the choice of seismic source model and the ground-motion prediction equation influences the results most. 相似文献
19.
In a previous paper (Makropoulos and Burton, 1985) the seismic hazard in Greece was examined in terms of magnitude recurrence using Gumbel's third asymptotic distribution of extreme values and concepts of the physical process of strain energy release. The present study extends the seismic hazard methods beyond magnitude to the estimation of expectations of levels of peak ground acceleration exceedance thus allowing for a direct comparison between these two methodologies as well as establishing information relevant to design and planning criteria.The limited number of strong motion records do not permit regional study of attenuation of ground vibration in Greece. An average formula is derived from eight well known formulae which resulted from worldwide studies, this is: a = 2164 e0.70m (r+20)−1.80 cm s−2 where a is peak ground acceleration, m is earthquake magnitude and r is hypocentral distance in kilometres. This formula agrees with the observed values of peak ground acceleration values recorded in Greece.Acceleration seismic hazard is calculated at each of six chosen cities. Values of maximum acceleration with probability 70% of not been exceeded in the next 25, 50, 100, and 200 years are obtained along with corresponding values of velocity and displacement. The same detailed acceleration evaluation is then applied to the whole area of Greece by dividing it into cells of 0.5° lat × 0.5° long, and the results are illustrated through isoacceleration maps.Differences in magnitude and acceleration hazard maps reflect the fact that in acceleration hazard assessment the focal distance from a particular place in an important factor. The cities of Heraklion and Rodhos have the lowest acceleration hazard although the expected earthquakes may have large magnitude. Intermediate depth earthquakes characterise these two cities. Acceleration estimates, unlike magnitude hazard parameters, refer to a particular place and not to an area around it. Hence, even if two places have similar earthquake depth distributions, the hazards may differ significantly because of the different spatial distribution of the foci. This is observed in the case of Athens and Corinth. These cities have almost the same magnitude hazard, but the acceleration hazard is much lower for Athens where the hazard is mainly due to more distant earthquakes.The isoacceleration maps for Greece as a whole also define areas of high seismic hazard. These are the areas around Cephalonia and Leukas Islands in the Ionian Sea and the eastern Sporadhes, Lesbos Islands and Chalkidiki in the Northern Aegean Sea. At the 70% probability level the maximum acceleration is expected to be around 0.2g within the next 50 years. The areas where the maximum acceleration at the 70% probability level is expected to reach a value of 0.3g in the next 200 years are around Cephalonia and Leukas Islands and near the Dardanelles. 相似文献
20.
沙牌坝址基岩场地地震动输入参数研究 总被引：2，自引：0，他引：2
重大水利水电工程地震动输入参数必须根据专门的地震危险性分析结果来确定。目前由地震危险性分析得到的一致概率反应谱具有包络的意义,不能反映实际地震的频谱特性,输入“一致概率反应谱”可能导致地震作用偏大;拟合设计反应谱人工生成地震动加速度时程的频率非平稳性也没有得到很好解决。为了解决这些问题,得到与坝址地震危险性一致、具体地震的输入参数,结合沙牌大坝提出了一套适用于重大水利水电工程基岩场地地震动输入参数确定方法：通过以有效峰值加速度为参数的概率地震危险性计算分析,确定坝址不同超越概率下的有效峰值加速度及对坝址贡献最大的潜在震源区;在最大贡献潜在震源内利用震级空间联合分布概率最大法确定坝址设定地震,依据加速度反应谱衰减关系确定与坝址设定地震对应的设计反应谱;根据设定地震结果和时变功率谱模型参数衰减关系确定时变功率谱,将时变功率谱和最小相位谱按三角级数叠加法进行强度和频率非平稳地震加速度时程合成。在对沙牌坝址区域的地震活动性及地震构造环境分析评价的基础上,采用上述方法,得到了坝址基岩场地不同超越概率下的有效峰值加速度、设计反应谱、强度和频率非平稳地震加速度时程等地震动输入参数。 相似文献