电网磁暴灾害风险影响因素研究综述   总被引：5，自引：2，他引：3       下载免费PDF全文

刘连光  吴伟丽 《地球物理学报》2014,57(6):1709-1719

磁暴是源自太阳磁场剧烈变化的地球空间效应,随着电网规模的增大和电压等级的增高,磁暴灾害已经成为诱发电网故障风险的威胁之一.研究电力系统磁暴灾害风险的影响因素可为预防与控制其引发的电网事故提供重要参考.在分析历史典型磁暴事件的基础上,剖析了磁暴诱发电力系统故障的机理,阐述了故障传播与电力系统响应的过程,总结了近年来关于影响电力系统的地磁感应电流水平及其产生的变压器无功损耗方面的研究成果,从磁暴本身的特点和电力系统的参数与结构两方面将影响因素分类.以GIC标准模型,通过改变磁暴扰动环境和电力系统参数,说明了各因素对电网磁暴灾害风险的影响程度,并比较了不同因素影响后果的差异,最后指出了尚未解决的问题和可能的研究方向.  相似文献   

Nonlinear response estimates of RC frames using linear analysis of SDOF systems          下载免费PDF全文

Saman Yaghmaei‐Sabegh  Shabnam Neekmanesh  Elisa Lumantarna 《地震工程与结构动力学》2014,43(5):769-790

An approximate‐simple method for nonlinear response estimates of reinforced concrete frames subjected to near‐field and far‐field records is presented in this paper. The approximate method is based on equivalent single‐degree‐of‐freedom and linear multi‐degree‐of‐freedom models. In this procedure, the nonlinear maximum roof displacement is estimated using an effective period factor and elastic response spectrum with an equivalent damping. The effective period factor was proposed for far‐field and near‐field ground motion records. For regions of high seismicity, the maximum roof displacement can be estimated by applying an effective period factor of 2.3 and 2.1 for near‐field and far‐field records, respectively, and 9% damped displacement response spectrum. For regions of moderate seismicity, a lower effective period factor of 1.9 and 1.8, for near‐field and far‐field records, respectively, can be applied to estimate the maximum roof displacement. A relationship between linear and nonlinear response of multi‐degree‐of‐freedom systems was also proposed to obtain estimates of the maximum inter‐story drift of nonlinear responding reinforced concrete frames. In addition, the effects of number of ground motion records used in the analyses on the scatters of results were investigated. The required number of ground motions to produce a reliable response was proposed. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Prediction of site factors by a non‐parametric approach          下载免费PDF全文

Iztok Peruš  Peter Fajfar 《地震工程与结构动力学》2014,43(12):1743-1761

The problem addressed in this paper is the estimation of the (de)amplification of ground motion at soil sites (compared to rock sites) as a function of the intensity of the ground motion. A non‐parametric empirical approach, called the Conditional Average Estimator (CAE) method, has been used, which is different from all existing approaches. Site factors (SFs) for sites characterized with V_s30 between 180 and 360 m/s were predicted for the peak ground acceleration (PGA) and the spectral accelerations by using a combined database of recorded ground motions. Based on the results of the study, site factors for PGA and selected spectral accelerations are proposed, separately for weaker and stronger ground motions. Comparisons are made with the SFs used in two standards (Eurocode 8 and ASCE 7‐10) and with SFs proposed in the literature, including four Next Generation Attenuation (NGA) ground‐motion prediction equations. The study reveals that (i) SFs depend strongly on the ground‐motion intensity. In the case of stronger ground motions, they decrease with increasing acceleration. (ii) The SFs predicted in this study agree reasonably well with the existing SFs in the case of weak ground motion. For higher intensities of ground motion, they are generally smaller than the existing ones. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Effect of a forced harmonic vibration pile to its adjacent pile in layered elastic soil with double-shear model     

《Soil Dynamics and Earthquake Engineering》2014

A new model named double-shear model based on Pasternak foundation and Timoshenko beam theory is developed to evaluate the effect of a forced harmonic vibration pile to its adjacent pile in multilayered soil medium. The double-shear model takes into account the shear deformation and the rotational inertia of piles as well as the shear deformation of soil. The piles are simulated as Timoshenko beams, which are embedded in a layered Pasternak foundation. The differential equation of transverse vibration for a pile is solved by the initial parameter method. The dynamic interaction factors for the layered soil medium are obtained by the transfer matrix method. The formulation and the implementation have been verified by means of several examples. The individual shear effects of soil and piles on the interaction factors are evaluated through a parametric study. Compared to Winkler model with Euler beam, the present model gives much better results for the dynamic interaction of piles embedded in stiff soil with small slenderness ratios. Finally, the effect of a forced long pile to a short pile embedded in multilayered soil medium is studied in detail.  相似文献   

《四川地震》期刊2001年至2010年质量分析     

格桑卓玛  吴江  陈秀波 《山西地震》2014,(4):43-45

根据2001年至2010年间"中国知网"针对《四川地震》进行的统计,简要分析了影响《四川地震》期刊质量的几个指标。结果表明,机构用户数量在2001年至2010年间一直在增加,但发行范围是稳定的,这说明地震专业性期刊的阅读者是特定机构的研究人员,而且在同一时期的来稿数量保持稳定也说明了期刊的稿源也局限在特定研究机构内;同时根据"中国知网"的统计反馈意见知道:影响因子的主要贡献因素是地震台站监测仪器革新技术和有关地震台站技术管理方面的文章;地震预测预报研究中的前兆观测项目分析这一类资料性文章是《四川地震》影响因子的次要贡献因素;其他类型文章的贡献还要小些。可以看出,地震台站观测技术创新型文章是《四川地震》期刊提高质量的关键因素。  相似文献   

影响康定地震台形变观测数据的主要干扰因素     

陈超  谭刚  张理  郭凤  康珠 《四川地震》2014,(4):22-26

对康定地震台地质环境及仪器安装作了简要介绍。整理、分析了康定地震台JB3M金属水平摆倾斜仪及VS型垂直摆倾斜仪在日常工作中观测数据受到的干扰影响,截取了相关干扰记录波形并且作出了对应说明。为台站工作人员在日常观测数据处理中提供实例参考,为地震分析预测人员提取康定台形变观测数据时剔除其中的干扰因素提供有效依据。  相似文献   

福建省地下流体观测干扰因素综合查询系统的设计与实现     

陈小云  李毅伟  黄永模  薛飞  江宁 《华南地震》2014,(4):51-54

将福建省地下流体观测网内观测井各测项在观测期间内出现的干扰事件进行汇总,并进行分类入库保存,实现地下流体干扰因素的录入、查询、检查、修改、计算。编制一个操作界面友好、功能全面的观测井各测项的正常动态与干扰因素综合查询系统,更好地发挥观测数据共享的作用,为分析预报人员查找干扰资料提供方便,同时为福建省地震地下流体观测井的效能评价提供指导作用。  相似文献   

六种不同煤阶煤的品质因子特征   总被引：4，自引：3，他引：1       下载免费PDF全文

许小凯  王赟  孟召平 《地球物理学报》2014,57(2):644-650

通过6种不同煤阶煤的弹性测试,分析了煤岩变质程度（以镜质组最大反射率表示）与煤岩品质因子之间的关系;在此基础上,进一步分析了煤岩速度与品质因子之间的关系及纵波与横波品质因子的各向异性特征.研究发现：煤岩镜质组最大反射率与纵波、横波品质因子均存在良好的线性相关性;垂直层理方向的波速与品质因子存在良好的线性关系,好于走向与倾向方向;垂直层理方向的纵波与横波品质因子线性相关,相关系数可达93.5%;煤岩的三方向品质因子存在各向异性,且强于速度的各向异性.通过横波品质因子与纵波品质因子间相互换算的理论公式计算结果与实验室实测结果的对比,证明了该理论公式的可靠性,误差小于10%,为多分量转换波的吸收衰减补偿提供了理论依据.  相似文献   

山东洞体应变观测质量分析     

李希亮  卢双苓  赵小贺  孟建国  李栋梁 《地震地磁观测与研究》2014,35(5):196-201

选取山东省3个洞体应变台2007-2011年观测数据,分析资料的完整性、内在质量及干扰因素.结果表明：①观测资料连续性和完整性较好;②仪器零漂满足设计指标要求;③M2波振幅因子相对误差和相对噪声水平达到Ⅰ类应变台标准;④仪器更新后观测质量提升;⑤洞体应变观测主要受仪器调修、气压、降雨和观测环境变化等因素影响.  相似文献   

Seismic performance and global ductility of RC frames rehabilitated with retrofitted joints by CFRP laminates     

M. Fakharifar  M. K. Sharbatdar  Z. Lin  A. Dalvand  A. Sivandi-Pour  G. Chen 《地震工程与工程振动(英文版)》2014,13(1):59-73

This paper presents a new FRP retrofi tting scheme to strengthen local beam-column joints in reinforced concrete(RC) frames.The new retrofi tting scheme was proposed following a preliminary study of four different existing retrofi tting schemes.A numerical simulation was conducted to evaluate the effectiveness of FRP-strengthened reinforced concrete frames by bridging behavior of local joints to the whole structure.Local confi nement effects due to varying retrofi tting schemes in the joints were simulated in the frame model.The seismic behavior factor was used to evaluate the seismic performance of the strengthened RC frames.The results demonstrated that the new proposed retrofi tting scheme was robust and promising,and fi nite element analysis appropriately captured the strength and global ductility of the frame due to upgrading of the local joints.  相似文献