Estimation of strong ground motion using accurate and efficient mesh-free finite-difference method

• Project/Area Number: 17K06531
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Kyoto University
• Principal Investigator: Takekawa Junichi 京都大学, 工学研究科, 助教 (70463304)
• Co-Investigator(Kenkyū-buntansha): 三ヶ田 均 京都大学, 工学研究科, 教授 (10239197)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 地震波伝播 / 強振動予測 / メッシュフリー差分法 / メッシュフリー法 / 差分法 / 表面波 / 地震波 / 強震動予測

Outline of Final Research Achievements

We developed a novel mesh-free finite-difference method for simulating seismic wave propagation with high accuracy and efficiency. The accuracy of the proposed method is validated by the dispersion analysis and comparison with analytical solutions. We also developed a new free boundary condition to implement arbitrary shaped topography. Many kinds of numerical experiments showed that the proposed method can reproduce surface wave propagation with high accuracy.

Academic Significance and Societal Importance of the Research Achievements

本研究により，地震波伝播現象を効率よく計算機内で再現できることが示された。これにより，地震が発生したときに各地がどの程度揺れるのかを事前に精度よく評価することができる（強振動予測）。また，目に見えない地下を可視化する物理探査手法においても，全波形逆解析手法などでは精度の良い地震波動場を効率よく計算する必要があり，この分野においても本研究で開発した手法が力を発揮すると考えられる。

Research Products

• [Journal Article] Free surface implementation in a mesh-free finite-difference method for elastic wave propagation in the frequency-domain (2019)
  • Author(s): Takekawa, J., Mikada, H.
  • Journal Title: Geophysical Prospecting Volume: 67 Issue: 8 Pages: 2104-2114
  • DOI: 10.1111/1365-2478.12825
  • Peer Reviewed
• [Journal Article] A mesh-free finite-difference method for elastic wave propagation in the frequency-domain (2018)
  • Author(s): Takekawa, J., Mikada, H.
  • Journal Title: Computers & Geosciences Volume: 118 Pages: 65-78
  • DOI: 10.1016/j.cageo.2018.05.011
  • Peer Reviewed
• [Journal Article] Frequency-domain acoustic wave modeling using a mesh-free finite-difference method with optimal coefficients of the acceleration term (2018)
  • Author(s): Takekawa, J., Mikada, H.
  • Journal Title: SEG Technical Program Expanded Abstract Volume: 37 Pages: 4030-4034
  • DOI: 10.1190/segam2018-2998173.1
  • Peer Reviewed
• [Presentation] 周波数領域メッシュフリー差分法による地表面形状を考慮し た弾性波動場の数値シミュレーション (2018)
  • Author(s): 武川順一，三ケ田均
  • Organizer: 資源・素材学会2018
• [Presentation] Frequency-domain acoustic wave modeling using a mesh-free finite-difference method with optimal coefficients of the acceleration term (2018)
  • Author(s): Takekawa, J., Mikada, H.
  • Organizer: SEG 2018 Annual Meeting
  • Int'l Joint Research
• [Presentation] An accurate and efficient finite-difference operator for the frequency-domain wave propagation (2017)
  • Author(s): Takekawa, J., Mikada, H.
  • Organizer: JpGU2017
  • Int'l Joint Research