Analysis on constituents of amplification and propagation of strong ground motion based on precise underground structure data

基于精确地下结构数据的强地震动放大和传播成分分析

• 批准号: 05680357
• 负责人: KUDO Kazuyoshi
• 金额: $ 1.28万
• 依托单位: THE UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680357/
• 关键词: Strong Ground Motion; Precise Underground Structure Model; Amplification and Propagation of Seismic Motion; Analysis for Constituent of Seismic Motion; 強震動; 細密地下構造; 強震動の要因分析

The aim of this research is to clearly understand the effects of local geology and/or underground structure model for estimating the earthquake ground motion by using the strong motion records and by carrying out several geotechnical measurements near the observation site.A very high acceleration of 1.6g was observed during the largest aftershock of 1993 Hokkaido Nansei-Oki earthquake at Otobe-cho, south-west coast of Hokkaido. In order to find the reasons of the very high acceleration, we carried out weak-motion array observation, small scale refraction survey and P-S logging using shallow borehole. Combining these data, we could understand as following :1) Shallow sediments overlaying very hard rock contribute to amplification of ground motion as much as 40 times at resonance frequency respect to rock site.2) Topographical effects are negligible.3) Nonlinearity of sediments at Otobe was very slight even in severe shaking, on the other hand, significant decrease of high frequency which implies nonlinear effects at deep sediment site (Kamino kuni) was found. The complexity of soil during an earthquake should be investigated using strong motion records.Propagation of long period strong ground motion depends on 2 or 3 dimensional underground structure. We examined this effects using strong motion records obtained in and around Kanto plain from the 1990 Izu-Oshima Kinkai earthquake and by numerical simulation for surface wave propagation in laterally heterogeneous media.

1993年北海道南西冲地震发生在北海道西南海岸的乙部町，在这次最大的余震中，观测到了1.6g的极高加速度。为了找出产生高加速度的原因，我们进行了弱动台阵观测、小尺度折射测量和浅井P-S测井。结合这些数据，我们可以得出以下结论：（1）覆盖在非常坚硬的岩石上的浅层沉积物对地震动的放大作用在共振频率上可达岩石场地的40倍之多。（2）地形的影响可以忽略不计。（3）即使在剧烈的震动下，音部沉积物的非线性也很小，另一方面，在深层沉积物场地（Kamino kuni），发现了高频的显著降低，这意味着非线性效应。利用1990年伊豆大岛近海地震关东平原及其周边地区的强震记录和横向非均匀介质中面波传播的数值模拟，我们研究了这种影响。

项目成果

Kudo, K.et al.: "Effects of surface soil and earthquake source radiation on the ground motion of 1. 6g acceleration, observed during the August 8, 1993, south-west off Hokaido earthquake, Japan." Prroc. 9th Japan Earthq. Eng. Symp.E(III). E043-E048 (1994)

Kudo, K.等人：“1993 年 8 月 8 日日本北海道西南地震期间观察到的表层土壤和地震源辐射对 1. 6g 加速度地面运动的影响。”

工藤一嘉: "強震動予測を中心とした地震工学研究のあゆみ" 地震,第2輯. 46. 151-159 (1993)

工藤和义：“以强地震动预测为重点的地震工程研究史”，《地震》，第 2 卷，第 2 卷，第 46 卷，第 151-159 卷（1993 年）

工藤 一嘉: "強震観測-現状と展望-" 地震2. 47. 225-237 (1994)

工藤一义：“强震动观测——现状与展望”地震2.47.225-237（1994）

Aguirre, J., K.Irikura, and K.Kudo: "Estimation of strong ground motions on hard rock and sediment sites in the Ashigara valley using the empirical Green 's function method." Bull.Disast.Prev.Inst.Kyoto Univ.Vol 44. 45-68 (1994)

Aguirre, J.、K.Irikura 和 K.Kudo：“使用经验格林函数方法估算足柄山谷硬岩和沉积物地点的强烈地面运动。”

工藤 一嘉: "強震観測-現状と展望-" 地震 第2輯. 47. 225-237 (1994)

工藤一义：《强震观测——现状与展望》地震卷2.47.225-237（1994）