共查询到19条相似文献，搜索用时 156 毫秒
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地下结构抗震理论分析与试验研究的发展展望 总被引：5，自引：0，他引：5
目前我国在地下结构抗震分析与破坏灾变机理研究中尚存在诸多问题需要解决,在分析总结我国地下结构抗震理论与试验研究的基础上,重点阐述了需要进一步深入研究的六个关键问题:地下结构振动模型试验研究技术,土体非线性动力本构模型,高轴压的地下结构承重构件地震破坏机理,非一致波动输入及非一致波动输入下地下结构的地震反应,饱和砂土液化大变形理论及本构模型,大型三维非线性土-结构动力相互作用分析模型。这些问题的研究和解决对于完善地下结构抗震理论分析方法与试验研究技术,获得大型地下结构在地震作用下的反应规律与破坏灾变机理具有重要的科学意义和工程应用价值。 相似文献
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对烟囱的震害规律进行了分析.认为地震时烟囱的破坏,竖向地震力起了很重要的作用.提出了用冲量法来计算烟囱的竖向地震作用,并以190 m 高的钢筋砼烟囱为例进行了计算.对计算结果进行了分析,并指出了烟囱设计中应注意的问题.进一步阐明了计算高柔结构和特定条件下某些结构的竖向地震作用的必要性. 相似文献
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城市立交桥结构三维地震反应 总被引：7，自引：3，他引：7
本文建立了城市立交桥结构地震破坏过程的分析模型，考虑了柱墩、梁、支座的单元模式，推导并建立了行波法输入下结构动力平衡方程，进而研究了地震多点输入下立义桥结构的地震反应问题，建立了立交桥结构的破坏准则，分别对几种方式地震输入下城市立交桥结构的地震反应瓿进行了具体研究。从而为人们对实际立交桥结构在地震作用下的破坏过程有了更科学的认识；在对桥梁结构进行地震反应分析时，不应该忽略地震对它的多方面的影响。 相似文献
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微倾斜场地砂土液化产生的土层侧移对地面结构和埋于其中的地下结构都造成了严重的地震破坏,也将会对地铁大型地下结构的地震安全造成严重的威胁。同时,地铁地下车站与区间隧道的连接部位因结构刚度的突变,必然会造成该部位结构的地震反应区别于标准段结构的地震反应。鉴于此,本文介绍了微倾斜(倾角为6°)可液化场地中两层三跨框架式地铁地下车站和区间隧道连接部位结构地震反应的大型振动台模型试验研究。通过对试验测试结果和试验现象的分析,揭示了微倾斜液化场地中地铁地下车站结构的动力反应规律及其地铁地下车站结构非均匀上浮机理,以及地铁地下车站结构与区间隧道结构的连接对各自动力反应的影响规律。 相似文献
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总结了土工动力离心模型试验在边坡的地震响应、动力破坏机理、液化大变形和土与结构物动力相互作用等研究中的应用现状，提出了目前边坡动力模型试验中存在的问题，以及今后的发展方向。 相似文献
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斜拉桥地震破坏的计算研究 总被引：10，自引：1，他引：10
地震曾破坏了大量的桥梁结构。然而，尽管目前世界上斜拉桥数目正以指数函数规律增长，但还没有任何斜拉桥经历过强地震，斜拉桥可能的地震破坏形式、破坏机理还是一个有待探索的领域。本文对本世纪几次大地震中严重破坏的桥梁进行损坏部分的震害原因分析，总结出一般桥梁结构地震破坏机理及破坏形式。利用大型结构分析程序ＭＳＣ／ＮＡＳＴＲＡＮ，对斜拉桥地震反应特征进行了分析，并在综合考虑结构地震反应的三维性、行波效应、非 相似文献
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论砖烟囱的地震破坏及其研究方法 总被引：5，自引：0，他引：5
王光远 《地震工程与工程振动》1983,(2)
本文从砖烟囱的地震破坏规律,它本身的构造特点、土壤和结构的共同工作、以及地面运动各种分量的联合怍用等方面讨论了对砖烟囱地震破坏的研究方法。 相似文献
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混合结构体系高层建筑模拟地震振动台试验研究 总被引：22，自引：2，他引：20
随着现代建筑高度的不断增加,混合结构体系在超高层建筑中逐步广泛应用,因此对该结构体系在地震作用下的破坏机理和抗震性能展开深入的研究是一项有意义的工作。本文对一混合结构体系复杂超高层建筑进行1／35的模型模拟地震振动台试验,分析模型结构的动力特性和不同烈度地震作用下加速度、位移和应变反应,然后根据相似关系推算出原型结构的动力特性和反应,研究其在各水准地震作用下的破坏机理和破坏形式,最后对原型结构设计提出若干建议。 相似文献
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Earthquake safety assessment of concrete arch and gravity dams 总被引：9，自引：1，他引：8
Based on research studies currently being carried out at Dalian University of Technology, some important aspects for the earthquake safety assessment of concrete dams are reviewed and discussed. First, the rate-dependent behavior of concrete subjected to earthquake loading is examined, emphasizing the properties of concrete under cyclic and biaxial loading conditions. Second, a modified four-parameter Hsieh-Ting-Chen viscoplastic consistency model is developed to simulate the rate-dependent behavior of concrete. The earthquake response of a 278m high arch dam is analyzed, and the results show that the strain-rate effects become noticeable in the inelastic range. Third, a more accurate non-smooth Newton algorithm for the solution of three-dimensional frictional contact problems is developed to study the joint opening effects of arch dams during strong earthquakes. Such effects on two nearly 300m high arch dams have been studied. It was found that the canyon shape has great influence on the magnitude and distribution of the joint opening along the dam axis. Fourth, the scaled boundary finite element method presented by Song and Wolf is employed to study the dam-reservoir-foundation interaction effects of concrete dams. Particular emphases were placed on the variation of foundation stiffness and the anisotropic behavior of the foundation material on the dynamic response of concrete dams. Finally, nonlinear modeling of concrete to study the damage evolution of concrete dams during strong earthquakes is discussed. An elastic-damage mechanics approach for damage prediction of concrete gravity dams is described as an example. These findings are helpful in understanding the dynamic behavior of concrete dams and promoting the improvement of seismic safety assessment methods. 相似文献
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Marta Giaretton Jason M. Ingham Dmytro Dizhur 《Bulletin of Earthquake Engineering》2018,16(1):295-313
Clay-brick unreinforced masonry (URM) chimneys are a common architectural feature of vintage domestic and commercial URM and timber-framed buildings widely encountered worldwide. URM chimneys include a cantilevered appendage above the roofline that during earthquakes-induced shaking is susceptible to significant damage and collapse, which can result in fatalities, injuries, and property damage. To mitigate this risk, many vintage URM chimneys are removed, braced, or eventually replaced with modern alternatives. The earthquake performance of 15,400 URM chimneys damaged during the 2010/2011 Canterbury earthquake sequence was investigated using a photographic database and insurance claims data. The widespread damage and failure of a large proportion of retrofitted chimneys was the impetus for an experimental shake-table testing campaign that was undertaken to assess the performance of five prototypical URM chimneys in their as-built and retrofitted conditions. Cost-effective retrofit techniques with low aesthetic impact, including the use of near surface mounted carbon-fibre reinforced polymer strips and post-tensioning, were investigated. Tested chimneys were constructed to replicate the most commonly encountered geometric characteristics and construction details collected during an in-field pilot survey of 351 undamaged vintage URM chimneys. 相似文献
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赵桂宝 《地震地磁观测与研究》2005,(Z1)
地球科学是一门观测科学,地震观测是研究与应用的基础。地电阻率作为地震前兆观测手段之一,发挥着日益重要的作用,而良好的观测系统是产出连续、可靠、高质量数据的前提。因此,对观测系统的数字化改造工作必须予以高度重视。本文对嘉山台地电阻率数字化改造工作进行了简要介绍,并就一些技术问题进行了论述。 相似文献
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During the past strong ground motions, chimneys constructed according to international standards are representative of similar structures at industrial areas throughout the world, including those collapsed or moderately damaged in earthquake-prone regions. This is due to the specialty of structural characteristics and the special loads acting on the structure such as earthquakes, wind and differences in the level of temperature, etc. In this context, the researchers and designers should focus on the dynamic behavior of chimneys especially under high temperature and seismic effects. For this purpose, the main focus of this study is to evaluate the dynamic response of a chimney under the above-mentioned effects considering soil-structure interaction (SSI). A 52 m steel chimney in Yeşilyurt township of Samsun City in Turkey was studied. The in-situ model testing and numerical models were compared. Before the commissioning of the chimney, a series of tests was realized to define its dynamic characteristics in case of no-heat and after the fabric got to work, the same tests were repeated for the same sensor locations to understand the heat effect on the dynamic response of the chimney. The ambient vibration tests are proven to be fast and practical procedures to identify the dynamic characteristics of those structures. The dynamic testing of the towers promises a widespread use, as the identification of seismic vulnerability of such structures becomes increasingly important. The data presented in this study are considered to be useful for the researchers and engineers, for whom the temperature and SSI effects on steel chimneys are a concern. Using the modal analysis techniques, presented finite element simulation for the soil/pile foundation-chimney interaction system is verified. The results of modal analyses using numerical solutions are shown to have acceptable accuracy compared with results obtained by in-situ test. The present study also aims to provide designers with material examples about the influence of these on the seismic performance of steel chimneys by means of reflecting the changes in the dynamic behavior. 相似文献
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首都圈地震重点监视区是我国地震重点防御区和地震监视预报研究的重要试验区,区内布有流体化学测点35个,开展的多项地震流体地球化学研究已取得丰硕的成果,为地震预报研究作出了重要的贡献。笔者对部分流体地球化学组分的区域特征进行了初步分析,结果表明氡、汞、氢等组分具有较好的映震效能,它们在正常状态下,普遍具有低背景值且变化幅度不大的共性,而当地震活跃时,大部分测点的上述组分的含量均出现增高现象,成为地震短期预报的依据之一。 相似文献
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TYPE AND DISPLACEMENT CHARACTERISTICS OF LINGSHAN M6¾ EARTHQUAKE SURFACE RUPTURE ZONE IN 1936, GUANGXI 
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下载免费PDF全文 LI Xi-guang PAN Li-li LI Bing-su NIE Guan-jun WU Jiao-bing LU Jun-hong YAN Xiao-min 《地震地质》2017,39(5):904-916
On April 1, 1936, an M6¾ earthquake occurred on the Fangcheng-lingshan Fault. So far, the Lingshan M6¾ earthquake is the biggest one in South China. There are some reports about the Lingshan earthquake fissures, but its surface rupture hasn't been systemically studied. Based on the geological mapping and measurement of the right-lateral displacement and vertical offset, the surface rupture zone caused by the Lingshan M6¾ earthquake was found, which contains two secondary surface rupture zones in the east and west respectively, its strike varies from N55°E to N60°E with en echelon-like distribution along the north section of Lingshan Fault, and its total length is about 12.5km. The western surface rupture zone locates intermittently along Gaotang-Xiatang-Liumeng, about 9.4km in length, with a right-lateral displacement of 0.54~2.9m and a vertical offset of 0.23~1.02m; the other one appears between Jiaogenping and Hekou, about 3.1km in length, with a right-lateral displacement of 0.36~1.3m and a vertical offset of 0.15~0.57m. The maximum right-lateral displacement and vertical offset are 2.9m and 1.02m, appearing at the east of Xiatang reservoir. The types of surface rupture mainly contain earthquake fault, earthquake scarp, earthquake fissure, earthquake colluvial wedge, earthquake caused landslide and liquefaction of sand and so on. The earthquake fault develops at the east of Xiatang and Jiaogenping, earthquake scarp appears at Xiaoyilu and Xiatang, earthquake fissure locates at Xiatang, there are multiple earthquake landslides along the surface rupture zone, and the trench LSTC03 exposes the earthquake colluvial wedge. In order to further investigate the Lingshan earthquake surface rupture zones, the author compares the parameters of Lingshan M6¾ earthquake with the similar typical earthquakes in western China, the results show that the parameters of Lingshan earthquake are similar to the typical earthquakes in western China. The length of Lingshan earthquake surface rupture is shorter, but the dislocation is bigger. The author considers that this is mainly related with the parameters of Lingshan earthquake, site condition and structural environment of surface rupture zone, the symbols of dislocation measuring, human activity and weather condition and so on. The research of surface rupture zone features and analysis of Lingshan M6¾ earthquake provides important and basic data for exploring the seismogenic structure of Lingshan M6¾ earthquake, and it has important scientific significance. 相似文献
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Liu Yaowei 《中国地震研究》2007,21(1):16-32
This paper presents a review of the development of scientific research and practice of earthquake underground fluid in China during the last 40 years, summaries early constructive research and primary achievements in this field. The science of earthquake underground fluid is closely correlated with earthquake monitoring and prediction, such as innovations in observation techniques and theoretical methods, and analysis of diversified parameters and research into predictive methods. The historical evolution of observation networks for underground fluid indicates that the demand for strong earthquake monitoring and prediction has become the driving force of the construction and development of the observation network. The development of observation techniques represents the trend based on multiform measurement, syntheses, and digitization. The study results of underground fluid theory and precursory mechanisms suggest that the precursory model, numerical simulation and in-door or field experimental research are the main technological approaches promoting innovation. Research results of earthquake forecast methods use physics based forecast techniques and the ideas of combination of usability and scientific advance. It has been proved by forecast practice that studying underground fluid is a very important subject in earthquake prediction on the Chinese mainland. Finally, the primary work and technical criterion on underground fluid are introduced, and some major scientific issues and development trends in different historical stages are summarized. 相似文献