Deveropment of high resolution tomography method based on coherent seismic wave

基于相干地震波的高分辨率层析成像方法的发展

• 批准号: 09555142
• 负责人: HIGASHIHARA Hiromichi
• 金额: $ 6.21万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09555142/
• 关键词: physical prospecting; controlled sources; earthquake prediction; elastic wave tomography; seismic motion

We have developed an active underground tomography system based on a new-brand idea. In 1997 fiscal year, we set up testing system and prepared the manufacturing of a seismic source which was the center of the present research. In 1998 fiscal year, we manufactured the source and installed it in the testing system. We have been running it and made improvements.(1) We established a prototype model of the accurately controlled artificial seismic source. In this source, an electric servomotor drives an eccentric mass. The frequency of the rotation is maintained extremely constant. As a result, the source could emit very pure sinusoidal wave.(2) We established a prototype model of a sensor unit, as a combination of high sensitivity feedback seismographs, amplifiers, AD converters and a PC.This PC manages the timing of AD conversion and condenses the data by stacking.(3) We also developed mathematical theory which affords the basis for the analysis of data. We made and tested several numerical analysis methods of elastic wave field including a semi analytic method of multi-layer medium a finite difference scheme. We have calculated many forward problems.(4) We attempted to build a new inversion algorithm that estimated the under ground structure. It was revealed, however, necessary to prepare a concise model of scattering of the elastic wave by inelastic region. We established a plan of new experimental study of this phenomenon.

我们已经开发了一种基于全新理念的主动式地下层析成像系统。在1997财政年度，我们建立了测试系统，并准备制造地震源，这是目前的研究中心。在1998财政年度，我们制造了源，并将其安装在测试系统中。我们一直在运行它，并进行了改进。(1)建立了精确可控人工震源的原型模型。在这个源中，电动马达驱动偏心质量。旋转的频率保持非常恒定。因此，该源可以发射非常纯的正弦波。(2)我们建立了一个传感器单元的原型模型，作为一个高灵敏度的反馈地震仪，放大器，AD转换器和PC机的组合。这台PC机管理AD转换的时序和压缩的数据通过叠加。(3)我们还发展了数学理论，为数据分析提供了基础。本文提出并验证了几种弹性波场的数值分析方法，包括多层介质的半解析法、有限差分法。我们计算了许多正演问题。(4)我们试图建立一个新的反演算法，估计地下结构。然而，它揭示了准备一个简明的模型的弹性波散射的非弹性区域。我们制定了对这一现象进行新的实验研究的计划。

项目成果

Ha Dong-Ho., and Higashihara H.: "Wave field generated by laterally vibrating source attached to the surface of elastic half space" Proceeding of Japan Society of Civil Engineers. 584. I-42,1-10 (1998)

Ha Dong-Ho. 和 Higashihara H.：“附着在弹性半空间表面的横向振动源产生的波场”日本土木工程学会论文集。

M.Hori and N.Vaikunthan: "Analysis of the initiation of periodically distributed defects." International of Plasticity. Vol.14, No.8. 673-688 (1998)

M.Hori 和 N.Vaikunthan：“周期性分布缺陷的引发分析”。

Dong-Ho HA Hiromichi HIGASHIHARA: "Wave field qenerated by latevally vibrating source attadsod to the surface of elastic lsalf space" 土木学会論文集. 584/I-42. 1-10 (1998)

Dong-Ho HA Hiromichi HIGASHIHARA：“由晚振动源 attadsod 产生的弹性空间表面的波场”日本土木工程师学会会议记录 584/I-42 (1998)。

Megawati K.,Higashihara H: "Crustal structure under the Akashi Kaikyo Bridge as revealed from explosion seismic experiments" 土木学会論文集. No.584/1-42. 11-18 (1998)

Megawati K.，Higashihara H：“爆炸地震实验揭示的明石海峡大桥下的地壳结构”，日本土木工程师学会会议记录，第 584/1-42 号（1998 年）。

M.Hori and H.Morihiro: "Micromechanical analysis on deterioration due to freezing and thawing in porous brittle materials" International Journal of Engineering Sciences. Vol.36.No.4. 511-522 (1998)

M.Hori 和 H.Morihiro：“多孔脆性材料冻融劣化的微观力学分析”国际工程科学杂志。