A Study on Impulsive Strong Ground Motion and its Observation

脉冲性强地震动及其观测研究

• 批准号: 11650485
• 负责人: KIYONO Junji
• 金额: $ 1.92万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650485/
• 关键词: Impulsive Wave; Fault Movement; High Frequency; Impulsive Force; Jumping Phenomena; FEM; Servo-type Accelerograph; Transducer-type Accelerograph; 兵庫県南部地震; 上下動; FEM; ジョイント要素; 破壊モード; 跳躍現象; 地震波; 断層近傍; 加速度波形; インパルス; 地震観測

The 1995 Kobe earthquake is one of the worst disasters in recent Japan history, because of not only total number of casualties but also the fact that the earthquake struck a highly urbanized area in which many buildings, housings and infrastructures were concentrating. The cause of damage to the structures is generally explained by the action of large horizontal ground motion. But all unusual phenomena observed for bridge piers, steel frames, foundation structures, various rigid bodies and so on have not been made clear. Discussion from the view point of vertical ground motion which is applied as an impulsive load is not still sufficient. It is a fact, however, that the seismographs did not catch such impulsive accelerations of vertical component. In this paper, damage to structures due to the strong ground motion is surveyed first and the relation between damage and input ground motion is investigated in order to find the existence and the effect of the impulsive wave. Two accelerographs of a servo type and a transducer type are compared to check the sensitivity of high frequency component. FEM analysis by using a fault rupture model is carried out and the effect of nonlinear elements on the vertical ground motion is studied.Main results obtained here is as follows :(1) The existence of impulsive strong force can not denied according to many unusual phenomena observed in the 1955 Kobe earthquake.(2) The amplitude of the up-down component of the earthquake becomes larger when the critical displacement of the fault is small and nonlinearity of the surrounding soil of the fault is considered.(3) When the high frequency more than 20-50 Hz exists in the record, the servo-type accelerograph can not detect such component.(4) The high frequency components have not observed in our observation site yet.

1995年的科比地震是日本近代史上最严重的灾害之一，这不仅是因为伤亡人数，而且因为地震发生在高度城市化的地区，许多建筑物、住房和基础设施都集中在那里。结构破坏的原因一般用大的水平地震动作用来解释。但是，对于桥墩、钢框架、基础结构、各种刚体等所观察到的所有异常现象还没有弄清楚。从竖向地震动作为冲击荷载施加的观点进行讨论仍然是不够的。然而，地震仪没有捕捉到这种垂直分量的脉冲加速度是事实。本文首先对强震作用下结构的损伤进行了研究，分析了损伤与输入地震动之间的关系，以探讨冲击波的存在及其影响。比较了伺服式和传感器式两种加速度计对高频分量的灵敏度。本文采用断层破裂模型进行了有限元分析，研究了非线性因素对竖向地震动的影响，得到的主要结果如下：（1）从1955年科比地震中观测到的许多异常现象来看，不能否认强冲击力的存在。(2)当断层的临界位移较小时，考虑断层周围土体的非线性时，地震的上下分量幅值较大。(3)当记录中存在大于20-50 Hz的高频时，伺服式加速度计无法检测到该分量。(4)在我们的观测点还没有观测到高频成分。

项目成果

清野純史: "計測震度の工学的吟味と組合せ震度導入の意義"土木学会論文集. No.682/I-56. 267-278 (2001)

Junji Kiyono：“测量地震烈度的工程检验以及引入组合地震烈度的意义”，日本土木工程师学会会刊第 682/I-56 号（2001 年）。

Sumio SAWADA: "Design Spectra for the Seismic Deformation Method defined on Ground Surface"Proc. of 2nd International Conference on Earthquake Geotechnical Engineering. Vol.2. 501-506 (1999)

Sumio SAWADA：“地表定义的地震变形方法的设计谱”Proc。

Junji KIYONO: "A Study on a Impulsive Strong Ground Motion"Proc. of Symp. II on Damage to Structure by Impulsive Effects of Hyogo-ken Nanbu Earthquake. 107-116 (2000)

Junji KIYONO：“脉冲强地面运动的研究”Proc。

Hitoshi MOROKAWA: "Phase Characteristics of Source Time Function Modeled by Stochastic Impulse Train"Proc. of 12th World Conference on Earthquake Engineering. (2001)

Hitoshi MOROKAWA：“随机脉冲序列建模的源时间函数的相位特性”Proc。

Hitoshi MORIKAWA: "Phase Characteristics of Source Time Function Modeled by Stochastic Impulse Train"Proc. of 12th World Conference on Earthquake Engineer. (2000)

Hitoshi MORIKAWA：“随机脉冲序列建模的源时间函数的相位特性”Proc。