MEASURES TO COPE WITH IMPULSIVE EFFECT OF NEAR-SOURCE EARTHQUAKE IN STRUCTURAL TRANSIENT RESPONSE

结构暂态响应中应对近源地震脉冲效应的措施

• 批准号: 11355025
• 负责人: NONAKA Taijiro
• 金额: $ 24.18万
• 依托单位: CHUBU UNIVERSITY (2000-2002)Kyoto University (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11355025/
• 关键词: IMPULSIVE; RUPTURE; WAVE; EARTHQUAKE; STRUCTURE; TRANSIENT; 兵庫県南部地震; 木造家屋; 跳び石; 耐震設計; 衝撃解析; 脆性破壊; 地震被害; 波動伝播解析; 動的設計法

Structural damage suffered from the 1995 Hyogoken-nanbu Earthquake (Kobe Earthquake) motivated the authors to initiate investigation into the quasi-impulsive effects of near-source earthquakes and to establish structural measures to cope with them. A cooperative research has been carried out involving various academic fields for four years since 1999, funded from Grant-in-aid for Scientific Research. Among significant research results, abstracted are the following :(1) The field surveys and rupture process observations of recent earthquakes have revealed that in Quindio earthquake, a large rupture occurred after a small initiation, and the big shake caused by the second event struck Almenia city, killing over 1000 people ; in Kocaeli earthquake, which killed over 30000 people, an earthquake fault appeared over a length of 100km, causing a maximum horizontal acceleration of 407gal and maximum vertical acceleration of 260gal near the fault ; in western Tottori earthquake, two clear phase … More s were identified, suggesting that the first rupture did not grow up continuously, but another big rupture succeeded later, indicating that shear stress might be completely and spatially released by large complex rupture around the second event. An earthquake"bright spot", proposed by Umeda, must have formed in a small confined region.(2) 3D dynamic finite-element simulation analyses have shown that the transient phase of structural response plays an important role, governed by stress waves, affecting heavily the following vibratory phase response, and possibly causing subsequent significant damage, in the case of severe earthquakes such as a near-source earthquake. The degree of this importance depends on ground-motion profile, site conditions and structural properties, such as shape, size, boundary or support condition, etc.(3) Actual severe damages in the Kobe earthquake were located near structural portions where abrupt changes in energy transmission must have taken place, with main rupture observed in heavy steel skeletons coinciding with such a location, and is understood as caused by this effect.(4) A particular large scale rupture experienced near a brace-column joint was initiated by brace breakage, which was caused by the combination of a great tensile axial force and transverse shear, and was transmitted to the adjacent column cross-section, which resulted in complete rupture.(5) Concentration of yield-hinge occurrence in a coincident story can cause severe whole story collapse. This is particularly dangerous, when occurred in an early phase of structural response to an earthquake.(6) In order to restrengthening an earthquake-damaged wooden house, a device of installing out-door metal poles together with bolted connections on the second floor level has been introduced, and found to be effective, transmitting horizontal resisting forces between the wooden frame and the poles, through experiment and earthquake response analyses.(7) As a result of Sharpy tests with varying speeds on steel specimens, it has been found that absorbable energy, and hence, fracture toughness also increase, as impact speed increases.(8) Sharpy tests have revealed that prestraining plays an important role in causing brittle failure of steel, and that plastic prestrain causes significant drop in absorbable energy capability. Less

结构性破坏遭受了1995年的淡南布地震（科比地震），促使作者开始研究近源地震的准冲动作用，并建立结构性措施以应对它们。自1999年以来，已经进行了四年的教练研究，该领域已有四年的历史，该领域由助学金资助科学研究。在重要的研究结果中，摘要是：（1）最近地震的现场调查和破裂过程观察结果表明，在Quindio地震中，在小启动后发生了很大的破裂，而第二次事件引起的巨大震动袭击了阿尔曼尼亚市，造成1000多人杀死了1000多人；在杀死30000多人的Kocaeli地震中，地震断层出现在100公里的长度上，导致407Gal的最大水平加速度和最大垂直加速度的260GAL在断层附近；在西部托托里地震中，发现了两个清晰的阶段……更多的S，表明第一次破裂并没有连续长大，但后来又有大破裂成功，表明剪切应力可能会被第二次事件周围大型复杂破裂在第二个事件周围完全释放。 UMEDA提出的地震“明亮斑点”必须在一个小的约束区域中形成。（2）3D动态有限元元素模拟分析表明，结构响应的瞬态阶段起着重要作用，受压力波的控制，受到严重影响的振动阶段，可能会导致较大的造成严重的造成较大的造成的造成严重的造成较大的造成的造成严重的地球，例如近距离地球上的近距离造成近距离造成的近距离造成近距离造成的造成的造成近距离造成的造成近距离造成的差异。这种重要性的程度取决于地面运动的特征，现场条件和结构性，例如形状，大小，边界或支撑状况等。（3）科比地震中的实际严重损害位于结构部分附近，在结构部分附近，必须发生能量传播的突然变化，并且在重型钢骨架中观察到的主要骨骼在较大的位置和该量构成的范围（4）构成的范围（4）构成（4）一定会引起的（4）效应。关节是由支架断裂引发的，这是由巨大的拉伸轴向力和横切剪切的组合引起的，并将其传播到相邻的柱横截面，从而导致完全破裂。（5）在巧合的故事中，屈服的浓度可能会导致严重的整个故事崩溃。这是特别危险的，当发生在对地震的结构反应的早期阶段时。（6）为了恢复地震损坏的木制房屋，已引入了安装户外金属杆以及第二层螺栓连接的设备，并发现有效，并在木制框架之间进行了敏锐的测试，并在木制框架之间进行了敏锐的测试，并将其用于敏锐的实验（7），这是7次反应（7）（7）。随着钢铁标本上的速度变化，已经发现，随着影响速度的增加，可吸收能量，因此断裂韧性也会增加。（8）敏锐的测试表明，在造成钢的脆性衰竭方面，塑料在引起可吸收能力的可吸收能力中显着下降。较少的

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