地震危险性分析中常见地震发生概率模型的合理性及局限性研究   总被引：2，自引：1，他引：1  

龚平  曾心传  罗延钟 《地震研究》2000,23(1):57-62

自本世纪六十年代末工程地震危险性概率分析法产生以来,地震发生的概率模型在工程抗震中开始受到极大的重视。人们企图尽可能客观地刻画地震事件序列以降低主观认识所造成的不确定性,提出了许多概率模型,并对这些模型进行了极为广泛的研究和探讨。笔人为这些探讨中大多数研究者们限于艰计数特征,与时间特征的探讨和计算简化处理,很少同时从概率统计、地震事件资料特征和工程近似三者的合理笥角度去分析这些模型的合理性与局际性  相似文献   

全球地震模型（GEM）研究进展综述及应用前景展望     

李昌珑  吴健  徐伟进  高孟潭 《中国地震研究》2017,31(1):1-11

本文综述了全球地震模型（GEM）组织的工作目标、主要职能、主要工具（OpenQuake软件）、主要研究成果,并对GEM今后的发展和应用趋势进行了展望。借鉴GEM和OpenQuake,可以进一步完善我国的地震危险性分析模型,提升大型活动断裂带附近大城市和重大工程设施地震危险性分析的科学性。  相似文献   

基于概率核地震属性融合的砂体预测方法研究     

杨宏伟  吴海燕  魏国华  钱志 《地球物理学进展》2020,(1):216-221

随着油气田开发程度越来越高,勘探难度越来越大,如东部的老油田已经进入开发的后期,如何识别薄层砂体是非常重要的工作之一,解决这些难题这势必需要更先进的技术.地震属性能够很好的反映砂体横向展布特征,但是单一属性无法定量预测砂体厚度,而多属性之间又存在多解性,因此有必要提炼地震属性之间的共同点,将地震属性进行信息融合,形成新的融合属性.针对这一问题,本文提出首先利用高频谐波提高地震数据的分辨率,在此基础上着重研究基于概率核的地震属性融合方法,融合了几种常见的地震属性,并结合波阻抗反演方法,预测了N873区块沙三6-3小层砂体厚度.结果显示该方法能够很好的反映砂体横向展布特征,避免了地震属性多解性问题,为提高砂体预测的精度,提供了新的思路和方法.  相似文献   

基于地震安全性评价的广东省地震危险性分析     

官幼雄 《华南地震》2019,39(1):71-75

地震安全性评价是防震减灾的重要措施之一。地震危险性分析是地震安全性评价的基础。论文利用安全性评价基本理论和方法对广东省的地震危险性进行分析。以广东省历史上发生的中强地震目录作为研究基础,分析了广东省的地质构造特点和断裂特点,划分潜在地震源、确定地震活动性参数,建立了地震发生概率模型,通过计算得出地震带的综合影响。研究结果表明广东省内具有发生7.5、 6.5、 6.0、 5.5级级段地震的发震条件,其中沿海地区是广东省中、强地震的主要发震区域。  相似文献   

洪水概率预报评价指标研究     

蒋晓蕾  梁忠民  胡义明  王军  李彬权 《湖泊科学》2020,32(2):539-552

在分析现有洪水概率预报评价指标的基础上,建立了洪水概率预报的"精度-可靠度"联合评价指标体系"精度"指标用于评价倾向值预报的准确性,包括确定性系数、相对误差等指标;"可靠度"指标用于评价区间预报的合理性,包括覆盖率、区间离散度等指标其中,在"可靠度"评价指标中,提出了一个新的评价指标,即覆盖率判定系数,用以评价多个区间预报结果的整体合理性以淮河王家坝区间流域为例进行应用研究,结果表明:"精度-可靠度"联合评价指标体系可以对洪水概率预报结果的合理性做出更全面的评价.  相似文献   

Risk acceptance criterion for tanker oil spill risk reduction measures     

Psarros G  Skjong R  Vanem E 《Marine pollution bulletin》2011,62(1):116-127

This paper is aimed at investigating whether there is ample support for the view that the acceptance criterion for evaluating measures for prevention of oil spills from tankers should be based on cost-effectiveness considerations. One such criterion can be reflected by the Cost of Averting a Tonne of oil Spilt (CATS) whereas its target value is updated by elaborating the inherent uncertainties of oil spill costs and establishing a value for the criterion’s assurance factor. To this end, a value of $80,000/t is proposed as a sensible CATS criterion and the proposed value for the assurance factor F = 1.5 is supported by the retrieved Protection and Indemnity (P&I) Clubs’ Annual Reports. It is envisaged that this criterion would allow the conversion of direct and indirect costs into a non-market value for the optimal allocation of resources between the various parties investing in shipping. A review of previous cost estimation models on oil spills is presented and a probability distribution (log-normal) is fitted on the available oil spill cost data, where it should be made abundantly clear that the mean value of the distribution is used for deriving the updated CATS criterion value. However, the difference between the initial and the updated CATS criterion in the percentiles of the distribution is small. It is found through the current analysis that results are partly lower than the predicted values from the published estimation models. The costs are also found to depend on the type of accident, which is in agreement with the results of previous studies. Other proposals on acceptance criteria are reviewed and it is asserted that the CATS criterion can be considered as the best candidate. Evidence is provided that the CATS approach is practical and meaningful by including examples of successful applications in actual risk assessments. Finally, it is suggested that the criterion may be refined subject to more readily available cost data and experience gained from future decisions.  相似文献   

Probabilistic analyses of a strip footing on horizontally stratified sandy deposit using advanced constitutive model     

R. Suchomel  D. Mašín 《Computers and Geotechnics》2011

An advanced hypoplastic constitutive model is used in probabilistic analyses of a typical geotechnical problem, strip footing. Spatial variability of soil parameters, rather than state variables, is considered in the study. The model, including horizontal and vertical correlation lengths, was calibrated using a comprehensive set of experimental data on sand from horizontally stratified deposit. Some parameters followed normal, whereas other followed lognormal distributions. Monte-Carlo simulations revealed that the foundation displacement u_y for a given load followed closely the lognormal distribution, even though some model parameters were distributed normally. Correlation length in the vertical direction θ_v was varied in the simulation. The case of infinite correlation length was used for evaluation of different approximate probabilistic methods (first order second moment method and several point estimate methods). In the random field Monte-Carlo analyses with finite θ_v, the vertical correlation length was found to have minor effect on the mean value of u_y, but significant effect on its standard deviation. As expected, it decreased with decreasing θ_v due to spatial averaging of soil properties.  相似文献   

珠江三角洲地震烈度概率危险性分析     

周克森 《华南地震》1995,15(3):1-6

根据我国东南沿海区域地质构造背景、地震活动的时空分布特征，对珠江三角洲地区的地震烈度水平进行概率危险性分析。基于区域内各统计单元及其潜在震源之间地震活动的时空非均匀性，本文给出的结果具有特定的统计意义。  相似文献   

Probabilistic sensitivity and modeling of two-dimensional transport in porous media     

M. C. Wu  J. D. Cawlfield 《Stochastic Hydrology and Hydraulics》1992,6(2):103-121

A reliability approach is used to develop a probabilistic model of two-dimensional non-reactive and reactive contaminant transport in porous media. The reliability approach provides two important quantitative results: an estimate of the probability that contaminant concentration is exceeded at some location and time, and measures of the sensitivity of the probabilistic outcome to likely changes in the uncertain variables. The method requires that each uncertain variable be assigned at least a mean and variance; in this work we also incorporate and investigate the influence of marginal probability distributions. Uncertain variables includex andy components of average groundwater flow velocity,x andy components of dispersivity, diffusion coefficient, distribution coefficient, porosity and bulk density. The objective is to examine the relative importance of each uncertain variable, the marginal distribution assigned to each variable, and possible correlation between the variables. Results utilizing a two-dimensional analytical solution indicate that the probabilistic outcome is generally very sensitive to likely changes in the uncertain flow velocity. Uncertainty associated with dispersivity and diffusion coefficient is often not a significant issue with respect to the probabilistic analysis; therefore, dispersivity and diffusion coefficient can often be treated for practical analysis as deterministic constants. The probabilistic outcome is sensitive to the uncertainty of the reaction terms for early times in the flow event. At later times, when source contaminants are released at constant rate throughout the study period, the probabilistic outcome may not be sensitive to changes in the reaction terms. These results, although limited at present by assumptions and conceptual restrictions inherent to the closed-form analytical solution, provide insight into the critical issues to consider in a probabilistic analysis of contaminant transport. Such information concerning the most important uncertain parameters can be used to guide field and laboratory investigations.  相似文献   

Some aspects of seismic hazard assessment when comparing different approaches     

Laura Peruzza  Dario Slejko 《Natural Hazards》1993,7(2):133-153

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