共查询到20条相似文献，搜索用时 62 毫秒
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台湾海峡7.3级地震建筑物震害分析与损失评估 总被引：1，自引：1，他引：1
对台湾海峡７．３级地震广东境内建筑物的地震破坏进行了调查，对地震损失进行了总体评估，并根据当地的工程地质情况，建筑物的结构，用材和施工特点等，分析了各种地震破坏形态和破坏规律，为今后的建筑抗震设防提出了有闪斩建议。 相似文献
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芦山7.0级强烈地震砖混民居震害调查与分析 总被引：1，自引：0，他引：1
2013年4月20日四川省芦山县发生Ms7.0级强烈地震,造成了大量民居建筑的严重破坏甚至倒塌.本文通过对芦山地震中民居建筑的震害调查,系统总结了砖混民居这一量大面广建筑结构的破坏形式和损伤机制.汶川地震后的新建民居在抗震措施方面有较大幅度的提高,比如大多具有抗震构造措施、采用240mm承重墙等,因此整体震害较轻,但是新建居民在建设房屋时,抗震构造措施的布局有很大的随意性,具体表现在平面内布置不足和竖向分布不规则,导致整体约束效果下降,进而结构发生破坏.雅安地区多处于山坡软土地带、建筑物多临近河流,同时民居建筑的基坑开挖普遍较浅,处理不当,在地震过程中出现地基不均匀沉降,基础遭到破坏,并造成上部结构破坏.相比之下,地基得到妥善处理、严格按照抗震规范设计的民居,震害十分轻微.本文建议继续增强对居民的防震减灾宣传,普及民居抗震构造知识,进行民居的实用抗震措施和地基处理方法的研究,并针对各类民居震害情况,研究有效、经济和快速的加固改造技术. 相似文献
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汶川地震中宝珠寺水电站遭受的地震烈度为8°(相当于水平峰值加速度0.2 g),远超过大坝的设计地震水平(0.1 g),震后大坝未见明显震损.为解释大坝在地震中的抗震现象,构建了坝址区三维模型.考虑坝体横缝非线性以及三个方向地震作用的不同组合方式,对汶川地震中大坝的动力响应进行有限元模拟.在此基础上,针对震后提高的抗震设防标准,进一步选取典型坝段,采用二维弹塑性方法对大坝进行抗震复核并分析可能的破坏模式.模拟结果表明:横河向地震分量起主导作用而顺河向地震作用相对较弱是宝珠寺重力坝在汶川地震中免于发生损坏的主要原因.坝顶混凝土发生挤压破碎缘于永久横缝在地震中高频渐开渐合行为引起的剧烈碰撞.宝珠寺重力坝对设计地震0.27 g的强震可以保持整体的安全性,对校核地震0.32 g的强震整体安全性降低,水库正常运行及抵抗余震的能力将受到影响. 相似文献
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汶川大地震震害特点与成因分析 总被引：3，自引：0，他引：3
郭迅 《地震工程与工程振动》2009,29(6)
2008年5月12日汶川地震造成巨大人员伤亡和财产损失.本文从工程抗震角度分析了震区房屋倒塌的原因,指出地震时房屋倒塌与否与诸多因素有关.在此基础上,分析了汶川地震震害严重的四个主要因素:震级大,烈度高,断层破裂长;震区人口稠密,房屋、路桥等人工工程多;抗震设防水平低;地震诱发地质灾害严重.最后,将汶川地震震害与1976年唐山地震震害作了对比.所得结论可供理解汶川地震震害、改进结构抗震设计参考. 相似文献
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基于VTK的医学图像系统研究 总被引：6，自引：0，他引：6
医学三维数据场可视化是当前科学计算可视化应用的重点。本文论述了可视化工具包VisualizationToolkit(VTK)的主要特点,介绍了三维医学可视化系统实现的原理和方法。根据一系列人体断面图像,应用VTK实现了三维医学图像重构,对重构后的三维图像进行解剖分析;并实现对人体的二维图像逐帧浏览及柱状统计。实验结果表明,VTK具有使用灵活,功能强大的优点,是医学三维数据场可视化的有力工具。 相似文献
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有关钢结构地震作用的讨论 总被引：2，自引：0，他引：2
简要介绍了6本国内标准(TJ11-74、TJ11-78、GB J11-89、GB50011-2001、JG J99-98、CECS160:2004)有关钢结构地震作用的计算方法,包括荷载组合方法和底部剪力法。通过归一化后的结果比较,评价了各本标准地震作用的大小。分析表明,除JG J99-98和GB50011-2001 2本标准由于考虑钢结构的阻尼比为0.02或0.035后,其地震作用有显著增大外,其它4本标准的地震作用处于接近的水平。考虑到钢筋混凝土和砖石结构等的地震作用水平在新旧抗震规范中并无多大变化,过分提高抗震性能较优的钢结构的地震作用水平显然是不合理的。 相似文献
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Occurrence of water ponding on soil surfaces depending on infiltration rates on Mongolian rangeland 
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下载免费PDF全文 Katori Miyasaka Sho Shiozawa Kazuhiro Nishida Siilegmaa Batsukh Shuichiro Yoshida Undarmaa Jamsran 《水文研究》2017,31(22):3996-4005
The occurrence of water ponding on soil surfaces during and after heavy rainfall produces surface run‐off or surface water accumulation in low‐lying areas, which might reduce the water supply to soils and result in a reduction of the soil water that plants can use, especially in arid climates. On Mongolian rangeland, we observed ponded water on the surface of a specific soil condition subjected to a heavy rainfall of 30 mm/hr. By contrast, ponded water was not observed for the same type of soil where livestock grazing had been removed for 6–8 years via a fence or for nearby soil containing less clay. We measured the infiltration rate (the saturated hydraulic conductivity of the surface soil, Ks) of the three sites by applying ponded water on the soil surface (an intake rate test). The results showed that Ks in the rangeland was lower than the rainfall intensity in the site where water ponded on the soil surface; however, Ks of the soil inside of the fence has recovered to 3 times that of the soil outside of the fence to exceed the rainfall intensity. Heavy rainfall that exceeds the infiltration rate occurs several times a year at the livestock grazing site where we observed ponded water. Slight water repellency of the soil reduces rain infiltration to increase the possibility of surface ponding for the soil. 相似文献
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基于地震动参数的建筑物震害研究 总被引：15，自引：3，他引：12
本文介绍了多步简化的push—over(MSP)方法,引导出求解单体建筑物易损性指数和群体建筑物易损性指数的办法,并通过建筑物平均易损性指数曲线,来评价城市的总体抗震性能。本文不采用过去以烈度为地震输入的易损性评定方法,采用地震动参数作为城市建筑物易损性的评定标准。给出的易损性指数曲线,可用来查找不同地震动参数下各类建筑物的易损性结果,比较城市各类建筑物的抗震性能。本文研究可望在城市建筑物震害评估中有好的应用前景。 相似文献
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断层错动对隧道的影响分析 总被引：1，自引：0，他引：1
隧道通过潜在地震地区时.存在活动断层的错动形成的重大工程地质问题的威胁.基于断裂儿何学和震源的运动学特征,以广州地区活动断裂为研究背景,通过在断层左右盘施加一定的速度荷载,模拟了断层错动达到0.28 m时对隧道的影响.得出隧道结构在断层错动影响下的位移和应力的变化规律.分别建立隧道结构距离断层50 m、100 m、150 m三个模型,比较了三种情况下的位移和应力状况.归纳出隧道与断层之间的安全距离. 相似文献
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Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological
effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating
risks due to ionization radiation. During the Work Package 2400 of the COST-724/WG-2 action, a number of spacecraft and aircraft
experiments have been performed with both active and passive detectors. A large data base has been created.
In this contribution we would like to stress the results obtained and their importance in three particular directions: (i)
Simultaneous investigation of galactic cosmic rays on aircraft and on the International Space Station (ISS); (ii) Onboard
spacecraft neutron contribution as estimated on the basis of the comparison of results measured with MDU/Liulin equipment
onboard ISS, foton capsule and a commercial aircraft flying at subsonic altitudes; (iii) Complex analysis of the results of
long term measurements onboard a Czech Airlines aircraft. The results obtained are presented, analyzed, and discussed, and
their complementary nature is underlined. The contribution represents a version of the Final Report of the Work Package 2400
of the COST-724/WG-2: Radiation Environment of the Earth. 相似文献
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Discontinuous anchored piling support (anchored soldier piles without lagging) is one of the most frequent earth-retaining systems used in temporary deep excavations in Santiago, Chile. The main advantages of using discontinuous piling support are their relatively low cost and ease of installation. This system is particularly efficient on stiff soils with deep groundwater table, conditions usually found in Santiago. This paper presents a numerical investigation of the characteristics of earthquake induced lateral pressures on discontinuous pile-supported excavations in Santiago gravel. An equivalent bi-dimensional plane-strain model was developed on the basis of a more refined 3D model in order to quantify the influence of the “arching effect” on the dynamic lateral earth-pressures. The dynamic response was studied for a suite of Chilean ground motion recorded on rock in order to evaluate the variability of the dynamic pressures and their influence on the piles' internal forces. These results are then compared against some simplified design recommendations. 相似文献