On the intensive impulse ground motion and the quasi-impact failures of civil engineering structure induced during the 1995, Hyogo-ken Nanbu earthquake.

1995年兵库县南部地震引起的强烈冲击地震动与土木工程结构的准冲击破坏.

• 批准号: 08458104
• 负责人: NAKAGAWA Koichi
• 金额: $ 4.29万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08458104/
• 关键词: Hyogo-ken Nanbu earthquake; impulsive ground motion; non-linearity of P-wave; tensile test; 3D FEM analysis; computer model simulation; model ground experiment; questionnaire survey

Information on the evidence of the impulsive seismic strong motion, especially, relating to the vertical motion have been collected and examined to clarify the mechanisms on quasi-impacted failure of civil engineering structure by 1995 Hyogo-ken Nanbu earthquake. One of the interests was pointed to revealing the fracture mechanism of reinforced concrete (RC) structures, especially yiaduct piers, due to strong vertical ground motions at the earthquake. For the sake of this, quasi-impact failure phenomena observed in this earthquake are first described. Second, stress propagation characteristics within a multi-layred ground model excited by vertical ground motions are discussed through a one-dimensional wave reflection theory. Third, a stress amplification phenomenon in the cross section of column in a viaduct pier under a pulse-like vertical stress induced at the bottom face of footing slab is examined by 3D FEM analyzes. Fourth, a possibility of quasi-impact failure of a reinforced con … More crete column is examined through 3D FEM analyzes for a viaduct pier model supported by a multi-layred ground model, and it was made clear that high frequency characteristics of vertical ground motions during earthquake gave the most significant effect on an axial impulsive failure of RC column due to strong tensile and compressive forces. Lastly, to verify the results obtained from the above numerical simulation, model tests by an underwater explosion method were carried out. As results, we could also pointed out the importance of high frequency characteristics of vertical ground motions for failure problems of viaduct piers.On the other hand, a mechanism on the generation of intensive impulse ground motion was discussed based on the laboratory test for model ground. The experimental results showed the remarkable non-linear effect on not only S-wave but also P-wave velocity and those waveforms depending on the amplitude. A possibility of the intensification of high frequency vertical strong motion within sub soli layrs was pointed under the consideration on the characteristics of dynamic behavior of the ground material and the deep geologic structure resulting in focusing rays of the body wave. Less

为了阐明1995年兵库县南部地震中土木工程结构的准冲击破坏机制，收集和检验了有关冲击地震强运动，特别是垂直运动的证据。研究的目的之一是揭示钢筋混凝土结构，特别是桥墩在地震作用下的断裂机理。为此，本文首先描述了在这次地震中观察到的准冲击破坏现象。其次，利用一维波反射理论讨论了竖向地震动作用下多层地基模型中的应力传播特性。第三，通过三维有限元分析，研究了在基础底板底面产生的脉动竖向应力作用下，高架桥墩柱截面的应力放大现象。第四，加固混凝土的准冲击破坏的可能性 ...更多信息 通过对多层地基模型支撑的高架桥桥墩模型进行三维有限元分析，发现竖向地震动的高频特性对钢筋混凝土柱的轴向冲击破坏影响最大。最后，为了验证上述数值模拟结果，进行了水下爆炸法模型试验。同时，通过室内模型试验，探讨了强脉冲地震动的产生机理。实验结果表明，非线性效应不仅对横波速度有显著影响，而且对纵波速度也有显著影响。考虑到地基材料的动力特性和深部地质结构导致体波射线聚焦的特点，指出了高频垂直强震动在土层内增强的可能性。少

项目成果

K. Nakagawa: "Pulse Transmission System for Measuring Wave Propagation in Soils" Journal of Geotechnical Engineering, ASCE. 122・4. 302-308 (1996)

K. Nakakawa：“测量土壤中波传播的脉冲传输系统”，岩土工程杂志，ASCE 122・4 (1996)。

K. Nakagawa: "Geology of Osaka basin and the Cultural heritages" Osaka City University International Symposium. (in press).

K. Nakakawa：“大阪盆地地质与文化遗产”大阪市立大学国际研讨会。

K.Nakagawa: "Development of Electrical Resistivity Measurement system of solls for laboratory and field use" Nondestructive and Automated Testing for Soil and Rock Properties,ASTM STP 1350. (in press). (1998)

K.Nakakawa：“实验室和现场使​​用的土壤电阻率测量系统的开发”土壤和岩石特性的无损和自动测试，ASTM STP 1350。（正在印刷中）。

園田 恵一郎: "地震による土木構造物の衝撃的被害について" 兵庫県南部地震における構造物の衝撃的破壊に関するシンポジウム(日本建築学会). 37-44 (1997)

Keiichiro Sonoda：“关于地震对土木工程结构的冲击损坏”关于兵库县南部地震期间结构冲击损坏的研讨会（日本建筑研究所）37-44（1997）。

中川康一: "地震動を規制する大阪盆地の地下構造要素-特に断層近傍の被害に関連して-" 地質学論集. (印刷中). (1998)

Koichi Nakakawa：“大阪盆地地下结构要素调节地震运动 - 特别是与断层附近的破坏有关 -”地质评论（1998 年）。