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1.
提出变电站地震可恢复性等级划分方法,设立评价变电站地震可恢复性的量化指标——可恢复性指数,给出基于建筑物和高压电气设备的权重系数与震害指数的变电站可恢复性指数计算公式,确定可恢复性指数与可恢复性等级对应关系,通过变电站实际震害与恢复样本研究建立变电站可恢复性矩阵。研究结果表明:随着可恢复性指数降低,变电站可恢复性越来越差,当可恢复性指数低于0.45时,变电站达到极难恢复的阈值;变电站所处的地震烈度越高时,变电站可恢复性就越低,恢复时间也越长。在9度区,变电站可恢复性指数开始快速降低,多数变电站为可恢复和难恢复,烈度为10度及以上地区,变电站极难恢复。 相似文献
2.
根据汶川地震各烈度区内变电站破坏状况、停运状况以及恢复时间的统计,分析了不同烈度区变电站地震破坏和功能失效特点和模式,定义了变电站震害指数,得出了设防烈度为Ⅶ度的变电站地震破坏和功能失效的震害指数与烈度的Di-Ⅰ关系曲线,并结合我国电力设施抗震设计标准,外推了设防烈度Ⅵ、Ⅷ、Ⅸ度变电站的Di-Ⅰ曲线,由此建立了基于抗震设防烈度和震害统计的变电站震害快速评估方法(FI-EDS法).通过德阳地区49个110kV及以上变电站的震害实例,对评估方法进行检验,结果表明,用本文方法快速评估得出的变电站破坏等级,0级偏差比率为47％,±1级偏差比率为45％,±2级偏差比率为8％.本文评估方法具有可接受的精度,并且可操作性强. 相似文献
3.
目前,《中国地震烈度表》(2008)对地震烈度的评定,依靠人的感觉、房屋震害、其他震害现象及水平地震动参数等指标。随着社会的发展、生命线地震工程研究的深入,在震后依据现行地震烈度表判定某地区的烈度时,存在一些不足之处。在这种背景条件下,考虑在地震烈度表中引入一些典型的生命线工程指标,用于辅助地震区地震烈度的评定,有一定的社会需求。本文以生命线工程地震烈度评定为研究的切入点,选择系统中典型结构物或设备进行地震烈度的评定,主要工作内容及成果如下:(1)对我国破坏性地震中典型桥梁震害进行了详细的分析,按照桥梁的结构形式、地震烈度、破坏部位、破坏部位的数量、桥梁的破坏等级、是否发生间接震害等分类整理汇总。根据现有桥梁的占有量,选择两类主要的桥梁类型——梁式桥和拱桥作为研究对象,以地震烈度为基本分类依据,寻找梁式桥和拱桥宏观震害与地震烈度间的关系。经统计分析,得到各烈度下梁式桥和拱桥出现各种震害的概率;得到各烈度下梁式桥和拱桥在完好、轻微、中等、严重和毁坏等5种破坏等级下出现的概率;得到各破坏等级下桥梁不同部位出现震害的概率;得到在各烈度下桥梁出现破坏部位种类的概率。将统计得到的概率简化,采用"个别、少数、多数、绝大多数"等不定量数词对各种震害或破坏等级进行限定,依据桥梁的破坏等级和破坏部位两种震害方式评价地震烈度,给出基于桥梁震害评定地震烈度的建议指标。该建议指标与现行地震烈度表模式相近,不定量数词范围定义一致,为地震烈度表中引入生命线工程的评价指标提供参考。(2)对我国破坏性地震中的变电站内的电力设备进行了广泛而细致的震害分析,总结电力设备的自身结构形状及材料构成特点,通过比较和综合归纳、统计分析,对变电站中变压器本体位移、变压器套管、断路器、隔离开关、CT、PT和避雷器等设备宏观震害进行研究,按照不同烈度进行分类统计。得到各烈度下各类设备震害出现的概率;判断各变电站的破坏等级,并得到各烈度下变电站出现完好、轻微、中等、严重和毁坏等5种破坏等级的概率;得到变电站各破坏等级下各设备出现震害的概率;得到各烈度下变电站内出现破坏设备种类的概率。将统计得到的概率简化,采用"个别、少数、多数、绝大多数"等不定量数词对电力设备各种震害或变电站的破坏等级进行限定,依据变电站的破坏等级和电力设备震害两种方式评价地震烈度,给出依据电力设备震害评定地震烈度的建议指标。该指标与现行地震烈度表模式相近,不定量数词范围定义一致,为地震烈度表中引入生命线工程的评价指标提供参考。(3)对我国破坏性地震中的供水管道进行了广泛而细致的震害分析,对国内外供水管道震害进行分析,总结其震害特点和震害规律。由于供水管道在地震中的易损程度较高,在VI度区庭院管道就可能发生破坏,且随地震烈度的增大,管道破坏也相应加重。此外,供水管道的震害受地震动参数、场地条件、管材特征、管材的设计、使用年限和施工质量等多种因素的影响,统计时很难给出精准的关系。本文从供水管道的区域平均破坏率和系统功能状态为切入点,对国内供水管道震害进行分析和统计,总结震害规律。选择单位长度内管道的破坏处数进行统计,得到各烈度下的供水管道破坏等级;总结各烈度下供水管线的震后水压、漏损率和功能失效时间一级系统功能恢复的难易程度,大范围内衡量了管道震害破坏程度。参考日本和前苏联地震烈度表中对管道的描述,结合震后供水管道的破坏等级和功能失效模式给出基于供水管道震害评定地震烈度的建议指标。(4)应用定性比较分析方法,找出各级地震烈度下,桥梁各电力设备中选定的震害之间的因果联系,确定各破坏同时出现的概率,相较于传统统计方法得到的"和/或"结论更为合理。这是定性比较分析方法在地震工程学领域的初次使用,为今后该方法在地震工程领域的应用奠定了一些基础。本文研究给出的建议指标与现行地震烈度表模式相近,不定量数词范围定义一致,可为地震烈度表中引入生命线工程的评定指标提供参考。 相似文献
4.
随着我国地震工程学的发展,烈度的应用范围渐渐发生了变化。通过整理半个多世纪的历史地震震害数据,发现整体趋势是,低烈度区的同类结构基本完好比例增加,其他破坏等级的比例下降,高烈度区同类结构的毁坏比例增加;收集近些年发生的汶川地震、芦山地震和鲁甸地震的部分震害数据,发现同一烈度区,设防、未设防的和不同设防等级的结构震害差别较大。如果烈度表达的是地震后果,则据这些后果平均水平判定的烈度应有不同,反证了烈度的含义是通过震害反映的地震作用。因此,借助不同建筑类型、不同设防等级的结构判定烈度时,需要相对统一的标准。由于我国丰富的震害资料来源于未设防结构,建议通过某个烈度下的不同设防标准、各类结构、各震害等级的平均震害指数和(或)破坏比与未设防同类结构的平均震害指数和(或)破坏比的统计关系,建立未设防结构对应的平均震害指数和(或)破坏比的调整系数,可据设防结构震害判定烈度。 相似文献
5.
基于综合震害指数的玉树地震烈度遥感评估研究 总被引：4，自引：0，他引：4
本文概述了地震烈度遥感评估的思路和方法,给出了遥感综合震害指数、地面等效震害指数计算的模型和地震烈度估计方法。利用2010年青海玉树7.1级地震发生后获取的主要地震灾区玉树县城区结古镇高分辨率航空遥感影像及其遥感震害解译结果和震后地震现场震害遥感比对科学考察成果,进行了结古镇的地震受灾程度和地震烈度的遥感评估。综合分析表明,玉树县城区遥感评估的地震烈度为IX度,与地面调查确定的地震烈度一致。文章最后对结果进行了讨论,表明遥感方法对应急烈度评估具有实用价值。 相似文献
6.
目前基于地震烈度的建筑物震害预测方法,通常按整烈度给出预测结果,造成在设定地震影响下烈度分界线两侧相邻的、抗震能力相同的建筑物震害预测结果有很大的差异,而同一烈度圈内靠近高烈度分界线与靠近低烈度分界线的建筑物震害预测结果却完全相同,这与实际震害情况严重不符。为了解决这个问题,将地震烈度按0.2度间隔进行分档,同时将震害指数和破坏等级也进一步细化出5个分档。按地震烈度与震害指数的关系,通过拟合方法和等分方法得到5个烈度分档的震害指数调整系数和分档震害指数,拟合方法获得的调整系数适用于群体房屋震害预测,等分方法获得的震害指数适用于单体房屋震害预测,通过改进方法获得的设定地震影响下震害预测结果,可以体现同一烈度不同烈度分档内建筑物震害差异,并使烈度线两侧,抗震能力相同的建筑物的震害预测结果不再出现跃变。 相似文献
7.
以2020年1月19日伽师M S6.4地震现场烈度调查结果为基础,综合余震分布、发震构造及仪器烈度值等研究成果,确定了本次地震的烈度分布。此次地震极震区烈度为Ⅷ度(8度),Ⅵ度(6度)区及以上总面积为7599 km 2。分析各个烈度区内不同结构房屋的震害,结果表明,震害较重房屋主要是由于这些房屋年久失修,施工质量不高,缺乏必要的抗震措施等自身原因造成的,其中没有抗震措施的砖木结构房屋是震害主体。随着新疆地区农村房屋的抗震性能提高,在以后的地震烈度调查中,需要现场调查人员依据不同结构房屋的破坏等级及平均震害指数等参数综合判定调查点的烈度值,在没有明显震害的低烈度区,仪器烈度值将会成为烈度图绘制的重要依据。 相似文献
8.
调查、搜集和研究了汶川地震中被评定为高危以上险情的147座小型水库土坝的地震破坏情况,给出了高危以上险情土坝的地震破坏程度划分为中等破坏、严重破坏和极严重破坏三个等级的原则和标准,以及土坝的地震破坏程度与地震烈度、土坝的宽高比、上游坡比、坝高的经验关系表,可发现:土坝的几何形状对其破坏程度起着重要的作用;对于6～8度地震烈度区,土坝的宽高比越小,或上游坡比越小,或坝体越高,则土坝的破坏程度越严重;对于9度以上地震烈度区,土坝通常发生极严重破坏。依据高危以上险情土坝的地震反应分析结果,给出了土坝地震破坏程度与土坝宽高比、坝高、土坝上游坡比及坝顶加速度放大系数、坝体最大动剪应力的经验关系曲线,发现在相同的地震烈度水平下,土坝的宽高比越小,或上游坡比越小,或坝高越大,且坝顶加速度放大系数越大或坝体最大动剪应力越大,则其地震破坏程度越严重;坝体最大动剪应力超过30kPa的土坝,通常发生严重或极严重破坏,坝体最大动剪应力大于100kPa的土坝,通常发生极严重破坏;土坝离发震断层越远,则其坝顶加速度放大系数越大。本文给出的高危以上险情土坝的地震破坏程度与坝体几何形状的经验关系,可为今后土坝抗震设计提供参考依据。 相似文献
9.
根据《中国地震烈度表》（GB17742-2020）中规定的仪器烈度计算方法处理门源M6.9地震强震动记录数据,得到测点仪器烈度值,将宏观烈度图Ⅵ度区以上站点与仪器测定烈度进行对比,发现44.44%站点测定的仪器烈度值与宏观烈度图中烈度区值完全吻合,88.89%站点的误差在±1度以内,说明《中国地震烈度表》建议方法获得的仪器烈度可以表征记录站点周边的震害程度;对比分析了基于PGA、PGV计算的仪器烈度值,发现在此次地震PGV中较PGA对于建筑物影响要明显,对震害的指示作用要优于PGA。基于仪器地震烈度值绘制了仪器地震烈度分布图,分布图整体上呈北西—南东方向展布,与宏观烈度走向基本一致。 相似文献
10.
青海省共和地区位于柴达木—阿尔金地震带内,具备发生中强地震的构造背景,近年来该地区地震活动频繁,农村地区受经济和技术等条件的限制,造成了巨大的人员伤亡和经济损失。为深入了解共和地区农村民居结构特征与抗震性能现状,开展实地调查,基于历史震害资料,总结区域内典型农村民居震害特点,并进行震害预测,得到不同地震烈度下农村民居不同的破坏结果。结果表明:青海省共和地区农村民居中的砖混结构和砖木结构房屋数量约占48%、47%,其中约68%砖混结构房屋未设置构造柱和圈梁等抗震设防措施;该地区主要农村民居基本达到Ⅶ度抗震设防要求,仅部分建造年代久的土木结构房屋破坏严重;地震烈度为Ⅷ度时,大部分房屋以中等破坏和严重破坏为主;地震烈度为Ⅸ、Ⅹ度时,农村民居将发生大范围严重破坏,甚至毁坏。 相似文献
11.
Yogui GT Santos MC Bertozzi CP Sericano JL Montone RC 《Marine pollution bulletin》2011,62(12):2666-2670
Limited information is available in the literature on the levels of brominated flame retardants in the southern hemisphere. This study presents concentrations of polybrominated diphenyl ethers (PBDEs) in the blubber of small cetaceans from the coast of São Paulo (Brazil), southwestern Atlantic. PBDE levels were highest in Stenellafrontalis (770 ng g−1 lipid) followed by Stenobredanensis (475 ng g−1 lipid), Sotaliaguianensis (65.6 ng g−1 lipid), Tursiopstruncatus (64.2 ng g−1 lipid) and Pontoporiablainvillei (60.3 ng g−1 lipid). In general, continental shelf individuals exhibited higher contamination than inshore animals. This might be related to larger prey items consumed by continental shelf dolphins. The pattern of contamination indicates that Penta-BDE commercial mixtures are a major source of PBDEs to top predators in the southwestern Atlantic. Congeners found in Octa-BDE formulations were not detected in the investigated animals. 相似文献
12.
Burša Milan Raděj Karel Šima Zdislav True Scott A. Vatrt Viliam 《Studia Geophysica et Geodaetica》1997,41(3):203-216
The geopotential scale factor R
o
= GM/W
o
(the GM geocentric gravitational constant adopted) and/or geoidal potential Wo have been determined on the basis of the first year's (Oct 92 – Dec 93) ERS-1/TOPEX/POSEIDON altimeter data and of the POCM 4B sea surface topography model: R
o
°=(6 363 672.58°±0.05) m, W
o
°=(62 636 855.8°±0.05)m
2
s
–2
. The 2°–°3 cm uncertainty in the altimeter calibration limits the actual accuracy of the solution. Monitoring dW
o
/dt has been projected. 相似文献
13.
外来种福寿螺(Pomacea canaliculata)相较我国本土螺类其牧食量更大且繁殖速度更快,对栖息地水生植物的现存量和实施水生植被恢复的生态治理工程的成功性可能构成威胁,目前对福寿螺影响浅水湖泊沉水植物的重建缺乏足够的研究.本文通过设置不同沉水植物种类组合系统,研究福寿螺对3种常用于浅水富营养化湖泊治理的沉水植物密刺苦草(Vallisneria denseserrulata)、轮叶黑藻(Hydrilla verticillata)、穗花狐尾藻(Myriophyllum spicatum)的牧食偏好以及不同植物配置系统理化因子的响应变化,结果表明福寿螺对沉水植物植株附着偏好为密刺苦草轮叶黑藻穗花狐尾藻,而牧食破坏强度为轮叶黑藻穗花狐尾藻密刺苦草,轮叶黑藻最容易受到福寿螺牧食影响而快速消亡,穗花狐尾藻叶片也会被全部牧食仅剩下茎,而苦草存活受到的影响较小.福寿螺会导致轮叶黑藻+密刺苦草组合系统中总氮、氨氮、总磷、正磷酸盐浓度显著升高,而密刺苦草+穗花狐尾藻组合中总磷、正磷酸盐浓度显著升高,但是在轮叶黑藻+穗花狐尾藻组合中仅总氮浓度显著升高.研究表明福寿螺能够影响沉水植物间的竞争关系,但是3种沉水植物均不能阻止福寿螺的牧食;福寿螺牧食会显著降低沉水植物生物量,最终会影响草型清水态系统的稳定性. 相似文献
14.
Nga Yu Ho Vincent Wai Tsun Li Wing Lin Poon Shuk Han Cheng 《Marine pollution bulletin》2008,57(6-12):425
kif7 is a member of the kinesin superfamily members which are molecular motor proteins that move along microtubules in a highly regulated manner through ATP hydrolysis. In this paper, we report on the cloning of the Oryzias melastigma kif7 (omkif7) using primers designed according to the Japanese medaka (Oryzias latipes) database. The cloned omkif7 has an open reading frame of 3762bp and is deduced to encode a polypeptide of 1254 amino acids that possesses the putative ATP-binding and microtubule-binding motifs in its motor domain at the N-terminal region. We characterized the cloned omkif7 by comparison with the zebrafish kif7. Both omkif7 and zebrafish kif7 are shown to be expressed in all embryonic stages and adult tissues examined with higher expression level in the testis and ovary. Whole-mount in situ hybridization revealed that the expression of omkif7 is ubiquitous during the early stages of embryonic development, but became more restrictive and localized to the brain, fin bud and eye at later development. This study suggested that the brackish O.melastigma can serve as a good seawater model organism for developmental studies by utilizing the resources developed from its close relative of the Japanese medaka. 相似文献
15.
Floristic surveys, vegetation mapping, and detailed transect analyses rendered a macrophyte flora of 14 native and five alien taxa of flowering plants in the River Erft, a contributory of the River Rhine in Northrhine-Westphalia. Water temperatures of this river do not fall below 10 °C all the year round, for reasons of geothermically heated water discharged from nearby opencast mining areas. Macrophyte stand structures, composed of the neophytes Azolla filiculoides and Lemna minuta (floating) and Myriophyllum aquaticum, Egeria densa, and Vallisneria spiralis (rooted in the muddy or sandy ground of the river) are described and the ecological requirements of these taxa are characterized. The alien species can be seen as elements that increase the α-diversity of the aquatic vegetation of the River Erft. They do not replace any of the native species, even if shifts in the competition dynamics occur. The colonization by neophytes of the abnormally warmed River Erft can be appreciated as paradigmatic for trends in the macrophyte vegetation of medium-sized rivers in Central Europe when climate-related or discharge-based heating of the waterbody occurs and propagules of alien plants imported by waterfowl or – more important – plants from aquarium waste will find suitable places of existence and spread. 相似文献
16.
Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest 总被引：2，自引：0，他引：2
In order to evaluate factors controlling transpiration of six common eastern deciduous species in North America, a model describing responses of canopy stomatal conductance (GS) to net radiation (RN), vapor pressure deficit (D) and relative extractable soil water (REW) was parameterized from sap flux data. Sap flux was measured in 24 mature trees consisting of the species Carya tomentosa, Quercus alba, Q. rubra, Fraxinus americana, Liriodendron tulipifera, and Liquidambar styraciflua in a bottomland oak-hickory forest in the Duke Forest, NC. Species differences in model coefficients were found during the 1997 growing season. All species showed a reduction in GS with increasing D. RN influenced GS in the overstory shade intolerant L. styraciflua to a larger extent than the other species measured. In addition, despite a severe drought during the study period, only L. tulipifera showed a decline in GS with decreasing REW. The primary effect of the drought for the other species appeared to be early autumn leaf senescence and abscission. As a result, despite the drought in this bottomland forest accustomed to ample water supply, maximum daily transpiration (1.6 mm) and growing season transpiration (264 mm) were similar to a nearby upland forest measured during a year of above average precipitation. These results may aid in assessing differences in water use and the ability of bottomland deciduous species to tolerate alterations in the frequency or amount of precipitation. Results also suggest little variation in water use among forests of similar composition and structure growing in different positions in the landscape and subjected to large interannual variation in water supply. 相似文献
17.
An Aphanomyces sp. (Oomycetes) was found to be an important egg parasite of Eudiaptomus gracilis (Copepoda) in Lake Mondsee (Austria). The infection is evidenced by densely packed infection hyphae, attached with holdfasts and wrapped around the female's abdomen. The infection hyphae give rise to hyphae which penetrate the egg sac, and subsequently kill all eggs. The infection obviously has no pathogenetic effects on the egg-carrying female. Infected females appear during summer and fall, mainly in warm water layers. Infected egg clutches are found at all seasons of the year, indicating considerable birth control of the Eudiaptomus population by parasite infection. It seems possible that the actual Aphanomyces sp. is not the only parasite involved. 相似文献
18.
The effects of a mixture of heavy metals (Pb, Zn and Cu) on growth, radial oxygen loss (ROL) and the spatial pattern of ROL were investigated in mangrove seedlings of three species: Aegiceras corniculatum, Avicennia marina and Bruguiera gymnorrhiza. Heavy metals inhibited the growth of seedlings and led to decreased ROL and changes in the “tight” barrier spatial pattern of ROL. There was a significant positive correlation between the amount of ROL from the roots of seedlings and metal tolerance. The species with the highest ROL amount, B. gymnorrhiza, were also the most tolerant to heavy metals. The “tight” barrier spatial ROL pattern was also related to metal tolerance in the seedlings. Therefore, we conclude that both ROL amount and “tight” barrier spatial ROL pattern in the roots of the mangrove seedlings play an important role in resistance to heavy metal toxicity. 相似文献
19.
The present paper analyses predation patterns, of Percichthys trucha and salmonid fish upon Galaxias maculatus in five lakes of northern Patagonia with differing community and environmental characteristics. Tank experiments were performed to evaluate relative efficiency of native and exotic predators of G. maculatus under treatments with and without cover (aquatic vegetation). Important differences were found between predators with regards to distribution and consumption of G. maculatus. Salmonids are more efficient than P. trucha in consuming G. maculatus in deep environments with scarcely vegetation; in contrast to native species they frequently use the pelagic environment. Although pelagic habitat might have served in the past as a refuge from native predators in the past, G maculatus now experiences intense predation in the pelagic zone by exotic salmonids. It is suggested that the widespread distribution of G. maculatus in Patagonian lakes may have facilitated the success of salmonids throughout Patagonia. 相似文献
20.
城市河道黑臭底泥对挺水植物光合荧光特性的影响 总被引：4，自引：1，他引：3
城市河道黑臭现象日益严重,探讨常见湿地植物在黑臭底泥中的生长,有利于为河道修复物种选择提供科学依据.研究黑臭底泥对3种常见湿地植物——菖蒲(Acorus calamus)、美人蕉(Canna indica)及慈姑(Sagittaria sagittifolia)生长状况和叶片叶绿素荧光参数的影响.结果表明:菖蒲和美人蕉在第30~40 d时生物量增量明显降低,慈姑的生物量增量在整个实验中持续增加;通过比较3种湿地植物的荧光参数可知,菖蒲和美人蕉的光化学淬灭系数(q P)、相对光合电子传递速率(r ETR)值在第10 d时达到最大,分别为41.33μmol/(m2·s)和68.60μmol/(m2·s),后30 d一直下降;慈姑q P、r ETR值在第30 d时增加;在第40 d时,美人蕉q P值下降,非光化学淬灭系数(q N)值上升,叶片有较强的热耗散能力,而菖蒲的q P、q N值同时下降,黑臭底泥对菖蒲叶片的光合系统PSⅡ造成伤害.这说明黑臭底泥对菖蒲和美人蕉的光合能力产生较长期抑制,而慈姑可较快适应黑臭底泥的胁迫.因此利用湿地植物修复黑臭河道时,可优先选择慈姑,其次是美人蕉,最后是菖蒲. 相似文献