ISSN2188－1200

2023 年度採択分 九州大学マス・フォア・インダストリ研究所 共同利用研究集会

デジタル化時代に求められる
斜面防災の思考法
編集 : 澤田茉伊

九州大学マス・フォア・インダストリ研究所

MI Lecture Note Vol.96 : Kyushu University2023年度採択分 九州大学マス・フォア・インダストリ研究所 共同利用研究集会

デジタル化時代に求められる斜面防災の思考法

編集：澤田茉伊

A

About MI Lecture Note Series
The Math-for-Industry (MI) Lecture Note Series is the successor to the COE Lecture
Notes, which were published for the 21st COE Program “Development of Dynamic
Mathematics with High Functionality,” sponsored by Japan’s Ministry of Education,
Culture, Sports, Science and Technology (MEXT) from 2003 to 2007. The MI Lecture Note Series has published the notes of lectures organized under the following two
programs: “Training Program for Ph.D. and New Master’s Degree in Mathematics as
Required by Industry,” adopted as a Support Program for Improving Graduate School
Education by MEXT from 2007 to 2009; and “Education-and-Research Hub for
Mathematics-for-Industry,” adopted as a Global COE Program by MEXT from 2008 to2012.
In accordance with the establishment of the Institute of Mathematics for Industry (IMI)in April 2011 and the authorization of IMI’s Joint Research Center for Advanced andFundamental Mathematics-for-Industry as a MEXT Joint Usage / Research Center in
April 2013, hereafter the MI Lecture Notes Series will publish lecture notes and proceedings by worldwide researchers of MI to contribute to the development of MI.
October 2022
Kenji Kajiwara
Director, Institute of Mathematics for Industry

Slope Disaster Prevention in the Digital Era
MI Lecture Note Vol.96, Institute of Mathematics for Industry, Kyushu University
ISSN 2188-1200
Date of issue: March 18, 2024
Editor: M ai Sawada
Publisher:
Institute of Mathematics for Industry, Kyushu University
Graduate School of Mathematics, Kyushu University
Motooka 744, Nishi-ku, Fukuoka, 819-0395, JAPANTel +81-(0)92-802-4402, Fax +81-(0)92-802-4405
URL https://www.imi.kyushu-u.ac.jp/

B

はじめに
斜面災害は，未だ予測の難しい現象であり，国内外で多大な人的・物的な被害が発生している。気候変動に伴う極端な気象に移行しつつある近年，これまで以上に斜面災害の予測は重要課題となっている。斜面災害の評価は，数理モデルとモニタリングを基礎とする。数理モデルには，地盤の変形や浸透を記述する力学モデルに加え，近年は DX, AI などの活用も試みられている。一方，モニタリングは地盤の変形，間隙水圧，含水量，温度等，崩壊と関係する計測項目は多岐にわたる。計測・通信技術の進歩に伴い，より高精度かつ密なデータの取得が可能になってきている。数理モデルの妥当性検証には計測データが不可欠であり，また計測データの補完や将来予測には数理モデルが不可欠である。両者の進歩によって，斜面災害の予測は実現される。
本研究集会は，九州大学マス・フォア・インダストリ研究所 2023 年度女性研究者活躍支援研究および国際地盤工学会 ATC1 の支援を受け，九州大学伊都キャンパス IMI オーディ
トリアムにて，2023 年 11 月 20 日 13:00-15:30 に開催された。数理モデルおよびモニタリン
グによる斜面災害の予測技術と管理・対策に関する最新情報の共有と，異分野および産官学の間のネットワーキングを目的とする。会場に加えて Zoom を併用したハイブリッド形式で実施し，国内外から 36 名が参加した。参加者は，地盤工学，砂防学，数学，情報学，環境工学等を専門とし，主な所属は，大学，民間企業（建設関連），法人研究機関であり，25%
が女性であった。
Chandan Ghosh 氏 （ National Institute of Disaster Management, India ） に よ る 講
演，”Bioengineering measures for slope stabilizations by vetiver grass system”，では，植物根を活用した斜面の補強法とインドでの実践例について紹介があった。北田奈緒子氏（GRI 財団）
よる講演，”Regarding ground risk assessment based on topographical and geological features”，においては，地形および地質学的観点から斜面災害リスクの高い地盤について解説があった。
酒井直樹氏（防災科学技術研究所）による講演，”Challenges in disaster response using slope
monitoring with ICT”，においては，地震後の熊本県のフィールド等での IoT センサや AI を使用したモニタリング事例の紹介があった。徳久晶氏（株式会社ケイズラブ）による講演，”Full-scale field experiment of debris flow and its generation mechanism”，では屋外での大規模な斜面崩壊実験と不織布を用いた対策工の効果について説明があった。吉川高広氏（名古屋大学）による講演，”Application of three-phase elastoplastic finite deformation analysis to slope
failure problem during rainfall”，では，不飽和地盤を対象とした構成モデルを用いた数値解析
による降雨時の斜面の安定性評価と，熱海の土砂災害への適用・崩壊メカニズムについて解説があった。澤田茉伊氏（東京工業大学）による講演，”Geotechnical approaches for preservationof openly exhibited Geo-relics damaged by rainfall infiltration”では，降雨で崩壊した遺構斜面のi

再現解析に基づく原因究明と修復・展示の手法について紹介があった。これらの講演に対して，会場およびオンラインの参加者から多数の質問が寄せられ，活発な議論が行われた。学生や若手研究者からの質問も多く，次世代の研究につながる情報共有の場を提供し，本研究集会の目的を達することができたと考える。
他に，講演者の Chandan Ghosh 氏については，11 月 22 日に防災科学ランチタイムセミナ
ーでの講演，11 月 18 日, 19 日, 26 日にそれぞれ東京都市大学，九州大学，Asian Institute ofTechnology の研究者らと地盤防災に関する意見交換を実施した。
謝辞：当研究集会を開催するにあたり，九州大学マス・フォア・インダストリ研究所より多大なるご支援を賜った。また，国際地盤工学会 ATC1 および CREST2023 SDGs 委員会より，
企画・広報の協力を得たので，ここに謝意を表する。
研究代表者
東京工業大学澤田茉伊

環境・社会理工学院
2024 年 2 月

ii

2023年度九州大学マス・フォア・インダストリ研究所 共同利用・共同研究

女性研究者活躍支援研究-研究集会（Ⅰ）

デジタル化時代にDisaster Prevention
求められる Slopein the Digital Era
斜面防災の思考法
参加
11.20
無料
MON
13:00-15:30

2023

九州大学 伊都キャンパス
IMIオーディトリアム

事前申込制

IMI Auditorium, Ito Campus, Kyusyu University

Language: English

ハイブリッド開催

主催
九州大学マス・フォア・インダストリ研究所

Institute of Mathematics for Industry, Kyushu University

組織委員

講演者
Prof. Chandan Ghosh,National Institute of Disaster Management, India

北田 奈緒子（GRI財団）
Dr. Naoko Kitada, Geo-Research Institute, Japan酒井 直樹（防災科学技術研究所）
Dr. Naoki Sakai, National Research Institutefor Earth Science and Disaster Resilience, Japan徳久
晶(株式会社ケイズラブ)
Dr. Aki Tokuhisa, K's Lab Inc., Japan

吉川 高広（名古屋大学）
Dr. Takahiro Yoshikawa, Nagoya University, Japan澤田 茉伊（東京工業大学）
Dr. Mai Sawada, Tokyo Institute of Technology, Japan

運営責任者【研究代表者】澤田茉伊（東京工業大学）

ハザリカ へマンタ（九州大学）
村井 政徳（清水建設株式会社）
河内 義文（株式会社ケイズラブ）
金谷 晴一（九州大学）
清野 聡子（九州大学）
水野 秀明（九州大学）
末政 直晃（東京都市大学）
松浦 一雄（愛媛大学）
西智美（福岡大学）
Bharat V. Tadikonda（Indian Institute of Technology, Guwahati）

Babloo Chaudhury（National Institute of Technology
Karnataka, Surathkal）

E-mail:imikyoten@jimu.kyushu-u.ac.jp
https://joint.imi.kyushu-u.ac.jp/post-9237/

iii

…開催日：2023/11/20～2023/11/20

デジタル化時代に求められる斜面防災の思考法｜2023a019
カテゴリー：イベント

タグ： 女性研究

研究集会I

…

プログラム
11月20日（月）13-16時
13:00 – 13:05
開会挨拶

CREST 2023 実行委員会委員長（ハザリカヘマンタ，九州大学教授）

13:10 – 14:45
講演

Prof. Chandan Ghosh（National Institute of Disaster Management, India）
Bioengineering measures for slope stabilizations by vetiver grass system
北田奈緒子（GRI財団）

Regarding ground risk assessment based on topographical and geological features酒井直樹（防災科学技術研究所）

Challenges in disaster response using slope monitoring with ICT
徳久晶（株式会社ケイズラブ）

Full-scale Leld experiment of debris Now and its generation mechanism
吉川高広（名古屋大学）

Application of three-phase elastoplastic Lnite deformation analysis to slope failure
problem during rainfall

澤田茉伊（東京工業大学）

Geotechnical approaches for preservation of openly exhibited Geo-relics damaged byrainfall inLltration

14:45 – 15:15

パネルディスカッション

15:15 – 15:30

ネットワーキング

15:30
閉会

iv

目

次

Bioengineering measures for slope stabilizations������������������1
Prof. Chandan Ghosh, National Institute of Disaster Management, Delhi, India

Regarding ground risk assessment based on topographical and geological features �� 13
Dr. Naoko Kitada, Geo-Research Institute, Japan

Challenges in disaster response using slope monitoring with ICT ��������� 23
Dr. Naoki Sakai, National Research Institute for Earth Science and Disaster Resilience,Japan

Full-scale field experiment of debris flow and its generation mechanism ������ 33
Dr. Aki Tokuhisa, K's Lab Inc., Japan

Application of three-phase elastoplastic finite deformation analysis to slope failure
problem during rainfall ��������������������������� 47
Dr. Takahiro Yoshikawa, Nagoya University, Japan

Geotechnical approaches for preservation of openly exhibited Geo-relics
damaged by rainfall infiltration ����������������������� 61
Mai Sawada, School of Environment and Society, Tokyo Institute of Technology, Japanv

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Bioengineering measures for Slope
Stabilisation
Chandan Ghosh
National Institute forof Disaster
DisasterManagement,
Management,Delhi,
Delhi,India
India

The Vetiver Grass Technology (VGT) is a low cost and extremely effective system for soil
and water conservation, pollution control, wastewater treatment, mitigation and prevention ofstorm damage and many other applications. Vetiver can be used in the tropics and semi
tropics, and where there are hot summers, and winters that do not include permanently frozen
soil conditions. Vetiver, although known as a grass, does possess several tree-like features. It
therefore becomes an attractive alternative to trees or shrubs when come to bioengineering
applications. Some of the potential applications of Vetiver system across the 100+ countries
demonstrate that this plant, even though originated in India, needs extensive research anddevelopments. The presentation highlights are:
 Landslides scenario – highlighting ineffective/inadequate drainage/stabilisation
measures that leads to progressive failure Hill widening by cutting hills that causes man-made landslides
 Live landslide hotspots where inappropriate technologies lead to failure Landslides prevention measures by conventional slope stabilisation methods, such as
gravity retaining walls and modern techniques using geosynthetics where a combination
with bioengineering measures ensures sustainability Important hill roads where slope stabilization measures are taken with extremely highcost but bio-engineering measures ensuring better safety with low or no cost
 Vetiver grass – it’s origin, properties and potential for erosion and landslide control Successful Application of Vetiver grass where conventional or many other methods
failed Application of Vetiver grass – giving examples of successful and failed application
many countries. It’s rather a permanent, low maintenance solution. Vetiver grass is aperennial plant, which provides a permanent solution with little or no maintenance Guidelines for Vetiver application siting several examples of landslides hotspots
exclusively or in combination with conventional slope retaining structures
 Vetiver grass supports local economies and Vetiver projects are labor intensive so they
employ locals, especially in rural areas. Vetiver foliage may be harvested for thatching,fodder, composting or other purposes where biomass is required Vetiver is non-competitive and Roots grow vertically downwards. Vetiver does notcompete with adjacent plants
 Vetiver has been shown to have very few pest or disease problems. Vetiver can checkweed invasion too. It can block the spread of other grasses including the world's worst
creeping grasses.
References[1] Vetiver Network International. URL
http://vetiver.orghttp://vetivernetinternational.blogspot.in/[2] Hawaii-Pacific Weed Risk Assessment. URL:
http://www.botany.hawaii.edu/faculty/daehler/WRA/full_table.asp
1

BIOENGINEERING MEASURES FOR SLOPESTABILIZATION

Prof. Chandan Ghosh, PhD(IIT-K), Dr. Engg (Japan)
http://disasterresilientindia.blogspot.in/https://www.facebook.com/chandan.ghosh.9887117
https://twitter.com/cghosh24
Email: cghosh24@gmail.com

Context▪ Geotechniques that we think we know off about

Landslides▪ Unpredictability domain of landslides
occurrences and limitations for Early Warning▪ Modelling and interpretations – not many vying
with Nature▪ Nature-based slope mitigation – our perceptions
falling apart and miles to go▪ Bio-engineering for landslides mitigation- caseexamples2Source: Can. Geotech. J. 58: 1915–1927 (2021)
dx.doi.org/10.1139/cgj-2020-0626
Study: Monotonic and cyclic behaviour of root-reinforced sand..

the friction angle upon extension increased significantly byapproximately 10° (from 41.9° (bare specimen) to 51.5° (rooted
specimen)) at a low confining pressure of <100 kPa

3Undrained compression and extension tests on bare androoted specimens (with RVR of 0.45%) at p0
c of 15, 30, 100, and 200 kPa: deviatoric stress (q) – axial strain (« a) curves

Inclined drain pipe – suitably be installed,very simple and no special tech required! How
to fit Soil mechanics principles here?

4Such culvert/cross drainage facility creation is time consuming
and costly..geotextiles wrap around pipe lines filled withsand-gravel mix is to be designed suiting site conditions, suchas amount of rain water/water fall discharge etc.

Reliable & cheaper Alternative
to Retaining/breast wall –Vetiver grass5Flyash dump site –stabilization by Vetiver
grass, India

9

We have similar cut-slope at
Ramban-Banihal and these areso easily solved by Vetiver!

6

Using same age old method—making slope more
vulnerable!! Nailed slopes are stable117

Flyash dump stabilization by
Vetiver8

Failure cases …due to post
plant care..using water for
2-3 weeks

Not caring enough after
vetiver grass plantation

9

How fast Vetiver grows? What’s
the economy?

Bio-engg. Solution paradigm▪

Composting / decompose organic compound▪ Waste water treatment
▪
▪
▪
▪
▪
▪

Remove Bad odour and sterilized harmful bacteria
Agriculture and gardening
Absorption of toxic gas like Methane and Hydrogen Sulphide(H2S)
Filling Up Dissolved OxygenControlling Temperature and pH
Absorption and Chelation of heavy metal and toxic organic compounds

Industries:▪

Sewage Processing Area▪

Process marine sewage▪

Animal Waste▪

Poultry Farm Sewage▪

Human Waste▪ Chemical Industrial Sewage▪ Service Water Processing
18

10

Use of Vetiver▪ Traditional medicine▪ Roots as water flavouring agent▪ Root mats for door, window screens during summer forcooling effect▪ For desert coolers in summer in North India▪ As eco-friendly soil binders▪ Roots for preparing Sharbat (sherbet) or soft drink
during summer, especially in North India▪ Socio-economic life of the rural population in India▪ Dried roots for scenting clothes▪ Dried culms as brooms and for thatching▪ Pulp of the plant for paper and straw board

THE VETIVER GRASS- CHARACTERISTICS

▪
▪
▪
▪
▪
▪
▪
▪
▪
▪

Grows under extreme and wide range of condition
Long Living Perennial Grass
Air temperatures: Sub zero to >55º C
Soil pH from <3 to >10
Annual Rainfall 200 mm to > 6,000 mm
Tolerant to high toxicity
Few Pests and diseases
Powerful (75 MPa root strength) and deep root system
Can withstand upto 5 months of submergence.
Non competitive and non invasive11

Thanks12

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Regarding ground risk assessment
based on topographical and geologicalfeaturesNaoko KITADA
Geo-Research Institute, Japan
日本列島は，４つの地殻プレートが会合した場所で形成された「島弧」であり，非常に複雑でバリエーションに富む地質が観察される地域である．そのため，構成する岩種や岩盤が風化して形成される土砂は地域によって鉱物組成が異なる．特に糸魚川‐静岡構造線を境として，東側（東日本）と西側（西日本）の地質や地形は大きく異なる．東側では中新世以降の火山岩類が広く分布し，時間経過とともに変質して不安定な土塊は地滑りや崩壊を発生させる．一方西側では，白亜紀に瀬戸内海を中心に花崗岩が大規模に貫入した．それらが風化してマサ化した土砂は，豪雨時の土石流などを発生させる．
また，西南日本に分布する中央構造線を境に南側では「付加体」と呼ばれる海洋プレート起源の岩石が分布する．
これらの地質のバリエーションは地域性のある地形を構成すると同時に，気候（特に降雨など）による変質，岩石風化による土砂の生成が地域毎に異なることから，地質リ
スクも地域によって異なる原因となる．よって，地域の地質と地形を知ることと，それによって発生する地質リスクを理解することは土地利用時には重要なポイントとなる．
事例として，東日本の日本海側を中心に分布する「グリーンタフ」は前述の火山岩類の一部が変質して生成した緑泥石がリスク要因となり，地すべりや崩壊を発生させる．
一方，西日本に分布する中央構造線付近では，広範囲に分布する断層破砕帯部において岩盤が脆く破砕あるいは粘土状のガウジなどに変化していることがリスク要因として，地すべりや崩壊の発生が高い．花崗岩地域のうち，花崗岩貫入の外縁部地域では急冷に伴う節理（亀裂）の発達が風化変質を促進してマサ化が進み土石流や崩壊を発生させる要因となる（千木良・加藤，2023）．付加体地域においては，層状の堆積岩が傾動していると，谷筋に沿って層理面が流れ盤になった場合，崩壊や地滑りを発生させる要因が高い．
いずれにおいても，地質の特徴や成り立ちを十分に把握することによって，地質特性
からリスクを予測することが可能であること，リスクを予測できれば，リスクを回避するための調査や設計，工法を選択して，安全な構造物が建設できる．災害や建設工事のトラブルを事前回避するためには，これらの地質学や地形学などの知識を活用することが大切であり，理学と工学の融合（協働）作業が必要であると考える．

参考文献：
千木良雅弘・加藤弘徳（2023）：花崗岩の冷却割れ目と岩体の内部構造，日本応用地質学会令和５年度研究発表会講演論文集，p61-62.

13

Regarding ground risk
assessment based on
topographical and geologicalfeaturesNaoko KITADA（Geo-Research Institute）

Areas at risk of disaster from a geological perspective
Characteristics of the constituent strata and rock bodies⇒

Characteristics of constituent minerals,
characteristics of strata composition

Tends to be susceptible to chemical and physical changes such asalteration due to water-rock reactions+ Volcanic debris (pumice, volcanic ash, etc.) ⇒ Altered and turned into clay
+ Granite ⇒ Weathered and mashed+ Fault ⇒ Clay at the fractured part
+ Bedding surface ⇒ Collapse due to flow bed

14

+ Most of the volcanic rocks produced bysubmarine volcanic activity during the
Miocene Neogene period are green in color,so they are called "green tuff." ⇒ The
pyroxene amphibole in the ejecta has
been chemically changed to chlorite (claymineral).

Green Tuff area

Green Tuff area

Median Tectonic Line area15

At the fractured part of the fault, the bedrock becomes fine-grained and turns into clay.

16

Green Tuff area

Median Tectonic Line area

Pink to Read are Granite

17

Granite+Weathered granite is brittle and will crumble into
pieces if you hit it with a hammer.

Weathering changes quickly

18

内帯

Areas of accretion ofocean floor sediments
due to platesubduction

外帯

Geological characteristics of the Kii
Peninsula - it's "accretion"！
Adduct zone

continental crust
Adduct zone

Adduct zone

19

＜Characteristics＞
Distributed in a band
EW ～ ENE-WSW
四万十帯の地質図（中屋他，1999）20

receiving board

flow board

流れ盤と受け盤の図と特徴

Slope direction and landslide of strata created from 10m DEM
Warm color:flow board. Cool color: receiving board

21

conclusion➢ It is important to understand geological and topographical features.

➢ Disasters occur due to natural phenomena such as meteorological phenomena
and earthquakes, and the ground and geological conditions of the area where thedisaster occurs are important points.
➢ When planning a city, it is important to understand and consider geological risks
in advance.

22

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Challenges in disaster responseusing slope monitoring with ICT
Naoki SAKAI
National research Institute for Earth science and Disaster
resilience(NIED), Japan
In our country, natural events such as
earthquakes, tsunamis, heavy rain, floods,
landslides, and volcanic eruptions
present various risks, intertwined withsocial conditions like complex value
chains, advanced land use, and an aging
population. Particularly in recent years,
there are concerns about widespreaddisasters caused by major earthquakes
and extreme rainfall, along with thepossibility of secondary disasters postevent, making disaster response andregional recovery increasingly complex.

Fig. 1 Overview of IoT slope monitoring system

In the field of disaster prevention and mitigation, a close collaboration between thephysical sciences, engineering, and social sciences is necessary. Although hazard
research has led to more detailed maps, a method for collaboratively solving thesubsequent steps of risk assessment and enhancing municipal response capabilities waslacking. One problem was the lack of a "unified disaster situation awareness" amongprofessionals from various fields, which led to unclear methods of concrete cooperation.
However, with the recent advancements in IoT (Internet of Things), measurements havebecome more accessible, making it easier to digitalize the previously analog world of
human intuition and experience, and to understand changes in real-time. Specifically forlandslide it is shown in Fig. 1. Such technological innovation has unified and visualized
phenomena, disasters, and social activities, enabling the "unified disaster situation
awareness."
To improve the resilience of local communities, it is crucial to have a flow ofvisualization of the current situation → decision-making → action. To seamlessly
connect these steps, visualization enabled by IoT, AI, and Big Data technologies isnecessary, and initiatives should be led by the private sector to foster inter-field
collaboration.
The initiatives mentioned above highlight the importance of a trans-disciplinary
approach (TDA), with a particular emphasis on decision-making based on information
underpinned by scientific evidence. If we can establish and standardize these concepts, itwill be possible to expand Japan's ICT-based disaster prevention technologies to theworld.

23

!Slope Disaster Prevention in the Digital Era", Institute of Mathematics for Industry(IMI),
Kyushu University, ISSMGE Asian Regional Technical Committee AsRTC1, 20/Nov./2023&'&()*++)*&'!"#$%

Challenges in disaster response using slope
monitoring with ICT!"#$%&'()$*+,+-$!"#$#%&'("#%)*()+,!"#$%&'()*"+%,*-'.%,*/'01,,('23('123(41)("'()5)4),3-'!"#$%&"'()*+*",-.(/&+#$#0#*(1%,(2",#.(3-$*&-*("&4(5$+"+#*,()*+$'$*&-*(6!/257(&'&()*++)*&'!"#$%

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24

&'&()*++)*&'!"#$%

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!"#$#%&'()'&*&+%"+,(-+./'0$%"/+1(2$3$'4(0$5#6(7*$89$%"/+(0$5#6(&%8:!
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NormalResponse
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4days ~
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2weeksfew months~ few months ~ few years

Support for evacuee’s life
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victims lives

Disaster Preventing Info.
Damage Situation Info.
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!"#$%&'($)"*+,+$-./"0(,%&%1%+"2'-"3$-%/"4.&+(.+"$(5"6&,$,%+-"7-+8+(%&'( !
Recovery Status Info.

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Case study of Emergency Responsein the 2016 Kumamoto Earthquake25

&'&()*++)*&'!"#$%

If rains, Residents are safe or not?

Slope fails
After earthquake,near slope area

Crack found!

Local government says,
residents leave here
immediately

How to monitor the slope near resident area&'&()*++)*&'
!"#$%

"

26

!"#$"%#& '()*+',#)-'.%/'$%.0)*1*/#!"#$%&'()*
Sensor #01

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UVO(PN!"#$<!"#$%&'()Sensor #04|}~*!"#$%&'().
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&'&()*++)*&'!"#$%

1#"-+#0-"2(/&#3*/(4-+5(6#7(/*"/#0(/'/+*$-./(#&*#.'0
1&12 %,3&($44&5&'.)&%&'For residents during raifall:
Slope monitoring delivered informationthat the slope is not active now.

&'&()*++)*&'!"#$%!"#$%$"&'(#)*$"'+(,-#".()&(/01#@ !"#$%&'()*($%*+@ ,$%-#&+(,.#/0+(#1#2&#&%)/@ 3%4#4&+5(6%47(6+1"8&%)/IRDR ICoE for Coherence among Disaster Risk Reduction,
Climate Change Adaptation, and Sustainable Development.
International activities require the "integration of knowledge"
in related fields.
https://www.bosai.go.jp/jhop/icoe.html
https://www.irdrinternational.org/@ 9,:(#/1(3;<3%0%&#$(:5#/4*)5-#&%)/=
28##

&'&()*++)*&'!"#$%

234++#.0#*)('$)+'54+)-'.%/'$%.0)6*%.0)728)
1.*"%.'"*+($'&$

6$*7#5"7&(8$'*"*+($'&$@ In 2018, this area is huge damaged with many debris flows along the valley.
@ Installing equipment based on the requirements of the residents with IoT/AI.
@ providing real-time landslide risk information with a hydorological simulation.
@ Using 3D-point cloud data to keep the safe infrastructures.
Landslide don’t occur often, Aim to realize the build back better with a quality of life. #!
&'&()*++)*&'!"#$%!"##$%&'()*+,-./0+%.,0&.-/1&,2/+,,-#-%' ,(,'-#• Monitoring of slope condition in local community by IoT sensor and AI• Warning sign by hydrological simulation of small river basin• Decision making based on physical evidence!
"!"# !"!"

29

&'&()*++)*&'!"#$%

Guidelines for the implementation of a community-based landslide early
warning system (ISO22328 Security and resilience — Emergency management)
The flow of warning information and evacuation commandEvacuation Map

Evacuation SOP&''()*++,,,-.)/-/01+/2(+3.+45+6.)/*)'7*.)/*!!8!9*:!*7.)*47:#*;#*45#%&'&()*++)*&'!"#$%!"#$%$"&'(#'2-'"3+(,+(405Transdisciplinary approach

From Japanese Society of Civil Engineering/-0123$%456(0#7,(48+"#$-7#-3&9+::(;+$(3,+-&30

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!"#$%

31

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Full-scale field experiment of debris
flow and its generation mechanism
Aki Tokuhisa
K’s Lab. Inc., Japan
1.
Introduction
In the heavy rainfall in the district of Chugoku, north Kyushu, Japan on 21 July, 2009, a lotof debris flows occurred around the boundary between Yamaguchi City and Hofu City.
These debris flows appeared on a rocky mountain where bedrock was exposed. The bedrockis weathered, the scree is thinly distributed on the ridgeline, and the soil and its granularity
are not consistent, which clearly led to marked irregularities in water permeability. In thispaper, for the purpose of clarifying the Rainfall infiltration and failure mechanism of source
head in Masado slope, we performed FEM analysis that reproduced these characteristics. In
addition, a full-size experimental model slope was created, and a rainfall experiment was
conducted under the conditions where a bare ground surface slope and the non-woven filter
were laid.
2. Full-scale field experiment
Our observations of the slope during the experiment were as follows.
a) Gully erosion
Immediately after rainfall hit the exposed slope, water flowing on the surface eroded ashallow gully in the lower part of the slope.
b) Boiling collapse
As the rainfall continued, the interstitial water pressure in the bedrock increased. When thisexceeded the weight of the clumps higher up, we saw the deep trench collapse. We refer tothis as a boiling collapse. The boiling collapse was especially notable on the lower part ofthe slope.
c) Slope failure conditions
As time passed, the downstream part eroded and the overall slope balance broke down. In
some cases, the collapse was such that clumps travelled downstream roughly 10 m. We
believe that debris flow occurs when this collapsed soil swells to the point that it flows on
the surface water draining downstream.
3. Seepage Flow Analysis by FEM
Where the high-permeability layer was distributed, seepage flow was an order of magnitude
higher than in the other cases with high-permeability layers, regardless of whether topsoil
was present, and we calculated the increase in pressure head over time. Further, the pressurehead value in the high-permeability zone increased steadily. When we calculated a safety
factor F, we found the safety factor F at 11:30, the time of the second round of rainfall wasless than 1.00. This analysis is in agreement with the time the debris flow occurred.
4.
Conclusions
A comprehensive examination of the two results shows that the presence of a high permeable
coarse grained layer between Masado layer and impermeable bed rock layer causes a sharp
rise in pore water pressure at lower part of the slope due to the effect of underground
penetration and groundwater funnel flow. The flow has become clear that the occurrence ofboiling causes the collapse. Moreover, the expected effect of non-woven filter which control
the seepage in heavy rain was confirmed.
33

Full-scale field
experiment of debris flow
and its generation
mechanism

TOKUHISA, Aki
K’s Lab. Inc.
November 20, 2023
Introduction
Torrential rain disaster in July 2009 in Chugoku and northern Kyushu.

234

Introduction
The embankment is formed around 30°gradient and 85 to
95％ compaction.

3

Characteristics of debris flow source headFern and shrub

Weathering granite
t=1.0～1.5m

Granite bedrock

Coarse grained or
gravel formation withhigh water
permeability

4

35

The Experiment Model Slope5

Build up the Experiment Model Slope
Artificial rain nozzle 100mm/h

pomp

Pore waterpressure data
30° acquisition device

Water
storage

W=10m
Water Reservoir

Filtration
device636Condition (1/3)
Composition of experimental embankment
Exp1
30°

Exp2

Bare ground
Weathering
GraniteBare ground
Weathering
Granite30°

Coarse sand
bed

1.0m
0.3m

1.3m

Exp3～5Filter 1～3
Weathering Granite

30°

Gravel bed

1.0m
0.3m

7

Condition (2/3)
Nonwoven filter：slope erosion prevent function
Porosity 98%
Soft matCan be planted by buried
seeds and flying seeds

Exp
No.

condition

thick
(mm)

3

Filter 1

17

4

Filter 2

125Filter 3

20
837

Condition (3/3)
Pore water pressure gauge：Exp 2～5
10.5m
9.5m

PP-3
PP-5

0.5m
PP-1

1m
PP-2
PP-4

PP-6

6m

10m

14m

9

Experimental results | Exp1,2
Events observed in the slope during the experiment
On the bare ground slope, shortly after the beginning of rainfall,
shallow grooved gully erosion occurred in the lower slope due tosurface water.
Exp2
Rainfall 10min.

1038

Experimental results | Exp1,2
A deep, 20-30 cm wide grooved collapse (boiling collapse)
occurred when the rainfall continued, the pore water pressure in
the ground increased and the upper soil cloth weight was
exceeded.
Exp2
Rainfall 271min.

11

Experimental results | Exp1,2

Pore pressure PP (kPa)

Exp2 Bare ground
Rainfall stop time

77

66

Collapse

55

Rapidlyrising

44

33
22
11

00

Main boiling collapse

No change

0
0

60
60

120
120

180
240
180
240
time (min)

39

PP-2
PP-4
PP-5
PP-6

300
300

360
360

12

Experimental results | Exp1,2
Just before collapse

destabilization

Boiling collapse spreads
throughout the slope bottom
13

Experimental results | Exp1,2

1440

Experimental results | Exp3-5

Pore pressure PP (kPa)

Exp4 Filter2
Main boiling collapse

Rainfall stop time

77
66
55

44
33
22
11
00

00

60
60

120
120

180
180

240
240

time (min)

300
300

360
360

PP-1
PP-2
PP-3
PP-4
PP-5
PP-6

15

Experimental results
The penetration of rainfall due to difference in constituent layers
2 hours from thestart of rainfall

Exp1

Exp2

Exp3

Exp4

Exp5

16

41

Analysis Methods, Models, and Cases
Heavy Rain 2.5～53.0mm/h
2325°Gravel t=0.3m
Weathering Granite t=1.0m

18

Top Soil13

t=0.3m

5°

8
3

20m

Fresh Granite-2-7

Lower edge: Leaching surface
0

5

10

15

20

25

30

35

40

45

50

55

17

Boundary condition
Rainfall waveforms on July 21, 2009 in “AMeDAS (Yamaguchi)”.
Time

6

7

8

9

10

11

12

Precipitation(mm/hr)

2.5

36.5

74.5

49.5

3.0

53.0

49.5

100
80
80
60
60
40
40
20
20
0
0

100

Precipitation(mm/hr)Debris flow
occurred

3

3

4

4

5

5

6

6

7 88 99
time (min)
7

42

10

10

11

11

12

12

13 14
14

13

18

Analysis Results
No top soil with high permeability layer and soil thickness ｄ=1.0ｍ
Pressurehead (m)

10
8
6
4
2
0
-2

Velocityv (cm/min)
The depth at
the study point
D (m)The head at
the study pointha (m)

23
v=0.046
D=14.141
ha=0.12818

13

v=0.053
D=17.250
ha=0.035

point 28v=1.250
D=16.353
ha=0.664v=1.142
D=13.364
ha=0.832

3-2-7

point 1

0

5

10

15

20

25

30

35

40

45

50

55

The pressure hydraulic head values of the high permeable
layer in the slope after 9:30 are gradually increasing.
19

Analysis Results
The safety factor F against boiling at points 1 and 2 was calculated fromthe following equation.

Gs－ 1
F＝

1＋e
ha

e：the void ratio＝0.8
ha：the head at the study point (m)D：the depth at the study point (m)DCases where F＜1

Gs：the specific gravity of soil particle＝2.62

No topsoil + high permeable layer

After the first heavy rain

9:30 F＝1.007
After the second heavy rain 11:30 F＝0.994

This coincides with the onset time of the debris flow .

I consider that the flow velocity did not cause seepage failure, but theincreased pressure hydraulic head reduced stability.

43

20

Summary
Collapse of debris flow source head
① Boiling collapse occurs in several
locations on the lower part of theslope, causing soil mass to washaway.
② The upper slope is out of balanceand collapse occurs around 0 to
20 m at the head of the source.
The collapsed sediment entrains
the surrounding surface water
during flow, resulting in high watercontent.
③ In addition, surface water increase
volume and velocity of the flow,
resulting in a debris flow.

Boiling collapse

high watercontent

source head
Around 0～20m

muddy water
occurrence of debris flow

21

Summary
The full-scale collapse experiment was conducted to observe thevariation of pore water pressure due to the effect of rainfall alone on
the slope. The peak time of pore water pressure is considered to beaccelerated because the valley topography where debris flows occur
is a concave profile and surface water from the surrounding area getsgathering.

This experiment

Actual valley shape

The effectiveness of the non-woven fabric filter in reducing infiltration
during heavy rainfall was confirmed, and it is considered to be
applicable as a preventive measure against debris flow.

44

22

Summary
Because the non-woven fabric filter is lightweight and easy to handle, it
can be installed at any location and at a lower cost than conventional
techniques such as mechanical installation.
Effects of Construction on Sources of Debris Flow and Landslides
Debris flow and landslides can be controlled.
The scale of erosion control weirs, etc. can be reduced, and costs
and construction period can be shortened.
Construction prior to erosion control weir construction will
prevent landslides during construction.

Enables low-cost debris flow countermeasures
23

End
24

45

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Application of three-phase elastoplastic
finite deformation analysis to slope
failure problem during rainfall
Takahiro Yoshikawa
Nagoya University, Japan
Numerous slope and embankment collapses have occurred due to heavy rainfall. Causes of
the collapses are considered as reduction of strength due to saturation of unsaturated soil
and rise in pore pressure and increase of self-weight due to water absorption. However, thedetailed collapse mechanism has not been elucidated. To elucidate the mechanism, soilwater-air coupled elastoplastic finite deformation analysis considering inertia force wereconducted. First, numerical simulations on deformation and failure of unsaturated slopes inrainfall model tests were performed. As a result, it succeeded in reproducing thedeformation-to-failure behavior of the model slope due to rainfall infiltration. The soil
element on the slip surface exhibited "softening behavior with plastic volume expansion"
above the critical state line in p’ – q skeleton stress space. Next, numerical simulations on
Atami embankment collapse on July 3, 2021, were performed. The results showed that alarge amount of groundwater flowing into the bottom of the embankment may have caused
softening behavior with plastic volume expansion in the soil in that area, leading to thefailure of the whole embankment.
References[1] Akira Asaoka, Toshihiro Noda, Eiji Yamada, Kazuhiro Kaneda and Masaki Nakano, An elastoplastic description of two distinct volume change mechanisms of soils, Soils Found. 42(5)(2002)
47-57. doi: 10.3208/sandf.42.5_47[2] Anusron Chueasamat, Toshikazu Hori, Hirotaka Saito, Tomotaka Sato, Yuji Kohgo,
Experimental tests of slope failure due to rainfalls using 1g physical slope models, Soils Found.
58(2)(2018) 290-305. doi: 10.1016/j.sandf.2018.02.003[3] Toshihiro Noda and Takahiro Yoshikawa, Soil-water-air coupled finite deformation analysis
based on a rate-type equation of motion incorporating the SYS Cam-clay model, Soils Found.
55(1)(2015) 45-62. doi: 10.1016/j.sandf.2014.12.004[4] Takahiro Yoshikawa and Toshihiro Noda, Triaxial test on water absorption compression of
unsaturated soil and its soil-water-air-coupled elastoplastic finite deformation analysis, Soils
Found. 60(5)(2020) 1151-1170. doi: 10.1016/j.sandf.2020.06.010

47

Application of three-phase elastoplastic
finite deformation analysis
to slope failure problem during rainfall
Nagoya University

Takahiro Yoshikawa

1

Background

Collapse of a road embankmentin the 2018 Japan floods

2021 Atami embankment collapse(from Shizuoka Prefecture)(from Tsuchida and Hashimoto)

Causes of collapse are considered as• saturation of unsaturated soil
• reduction of strength due to rise in pore pressure• increase of self-weight due to water absorption

However, the detailed collapse mechanism has not been fully elucidated.

48

2

BackgroundPrediction of the collapse of slopes / embankments due to rain
A combination of seepage flow analysis and stability analysis is used:using the stress state obtained from a seepage flow analysis, a stability analysis
that determines whether the safety factor exceeds 1 or not, is performed.

However, it is necessary•

to analyze slopes / embankmentsfrom deformation to failure caused by seepage•

to use a finite deformation analysis considering geometric nonlinearity
in order to simulate large deformation behavior from deformation to failure•

to consider inertial forces since failure is accompaniedby accelerated motion even if the external force is rainfall

3

PurposeThree-phase elastoplastic finite deformation analysis considering inertia force
is used to elucidate the collapse mechanism due to rainfall.

4
Time (min)6­6[10 ]

Velocity (m/s)

1Velocity = 0

0
­1
0

2
4
Time (min)6

Suction = 0 kPa
Net stress = 150→140 kPa

0

10

20

30

300
200
100
0

Axial strain (%)

40

Acceleration = 0

­2
­4
0

2

4

Time (min)

6

80
70
0

10

20

Axial strain (%)

400

300
200

Suction = 20→0 kPa
Net stress = 200 kPa

100Suction = 0 kPa
Net stress = 150→140 kPa

0100 200 300 400 500

­2

90

500

400

0

Mean skeleton stress (kPa)

100

2

500

0
1

Compression

2
3
4

0

10

20

Axial strain (%)

20

30

30

200
100
0

100 200 300 400 500
Mean skeleton stress (kPa)

100

­2

90
80
70
0

q = p'300

Axial strain (%)

Expansion­1

10

Deviator stress (kPa)

Suction = 20→0 kPa
Net stress = 200 kPa

100

Deviator stress (kPa)200

Deviator stress (kPa)300

q = p'Volumetric strain (%)­4[10 ]

2

400

Softening behavior withplastic volume expansion
above q=Mp’

Analysis

Degree of saturation (%)

0

500

400

0

Degree of saturation (%)

10

Reproduction of failure
behavior accompaniedby acceleration

500

Volumetric strain (%)

Experiment
Computation15

Deviator stress (kPa)

20

Reduction of suction
Increase in pore pressure

Experiment25

Acceleration (m/s 2)

Axial strain (%)

Water absorption failure of
triaxial specimen

10

20

Axial strain (%)­101

Expansion

2
3
4

Compression
0

10

20

Axial strain (%)

Application of this analysis method to simulation of a rainfall model test and a real problem

49

30

4

Outline of analysis methodu-pw-pa formulation◆ Eq. of motion𝜌𝜌𝒙𝒙ሷ s = div 𝑻𝑻 + 𝜌𝜌𝒃𝒃

𝜌𝜌𝒗𝒗ሷ s +𝜌𝜌w 𝑠𝑠 w + 𝜌𝜌a 𝑠𝑠 a tr 𝑫𝑫s +𝑛𝑛𝑠𝑠 w 𝜌𝜌w w 𝑛𝑛𝑠𝑠 a a𝑝𝑝ሶ +𝑝𝑝ሶ + 𝑛𝑛 𝜌𝜌w − 𝜌𝜌a 𝑠𝑠ሶ wሜKw
RΘ

Material time derivative viewed from the soil skeleton
Finite deformation analysis based on Updated Lagrangian𝒗𝒗ሶ s − 𝒃𝒃 = div 𝑺𝑺ሶ 𝒕𝒕

Rate-type（including jerk term）◆ Soil skeleton-water coupled eq.
◆ Soil skeleton-air coupled eq.
Numerical analysis method
Spatial discretization of the soil skeleton Finite element method
Spatial discretization of the pore fluid

Finite volume method (from Christian and Tamura)Temporal discretization

Linear jerk method (following Wilison’s θ method) and trapezium rule

5

Outline of analysis method◆ Skeleton stress eq.
−𝑻𝑻′ = −𝑻𝑻 − (𝑠𝑠 w 𝑝𝑝w + 𝑠𝑠 a 𝑝𝑝a )𝑰𝑰 = −𝑻𝑻 − 𝑝𝑝a 𝑰𝑰 + 𝑠𝑠 w (𝑝𝑝a − 𝑝𝑝w )𝑰𝑰◆ Constitutive eq.

Elastoplastic constitutive eq. SYS Cam-clay model considering unsaturated effect◆ State eq. of pore air

Referring to Kyokawa et al. (2009) and Zhang & Ikariya (2011),
larger intercept of NCL and CSL, lower the degree of saturation.

State eq. of an ideal gas◆ Unsaturated hydraulic property
𝑆𝑆e = 1 + (𝛼𝛼𝑝𝑝s )𝑛𝑛 −𝑚𝑚

11

𝑘𝑘 w = 𝑘𝑘sw ⋅ 𝑆𝑆e 2 1 − 1 − 𝑆𝑆e mvan Genuchten – Mualem model

50

m 2

1

1

, 𝑘𝑘 a = 𝑘𝑘da ⋅ 1 − 𝑆𝑆e 2 1 − 𝑆𝑆e m

2m

6Application to simulation of a rainfall model test

Overview of model tests and analysis conditions
1g model tests by Chueasamat et al. (2018)

Analysis conditions

7

2D plane strain condition◼ Seepage face
/ Rainfall condition◼ Exhausted condition

Rainfall intensity:25, 50, 100 mm/h
(K sand)

Rainfall intensity:25, 50, 100 mm/h

Dr: 0, 25, 50 %(Sr = 29-34 %)◼ Undrained condition◼ Unexhausted condition◼ Seepage face condition◼ Unexhausted condition

Dc = 100 % (Sr = 61 %)Parameters for SYS Cam-clay model••: Water pressure measurement point

51

DL clay: Values from Yoshikawa & Noda (2020)
K sand: Values for DL clay when Dc = 80 %Overview of model tests and analysis conditions
K sand (surface layer)

DL clay (foundation)

Analysis condition

Analysis condition

0

0

Saturatedhydraulic conductivity

86.68×10-7 m/s

1.25×10-4 m/s

Deformation and failure simulations for three casesof rainfall intensities of 25, 50, and 100 mm/h

Analysis results (Rainfall intensity: 100 mm/hour)
Degree of saturation (%)

Pore water pressure (kPa)

Experiment

Analysis9

Output at equal time intervals

Shear strain (%)

t = 43 min

t = 0 minReproductionof change inpore watert = 36 minpressure withtime

t = 18 min

52

t = 36 min

Reproductionof slip failure
behavior

10Analysis results (Rainfall intensity: 100 mm/hour)

Deviator stress q (kPa)

Immediately
before rainfall

2
1
0

0

10 20 30 40 50
Shear strain s (%)

1
0
­1
­2
­3

0

10 20 30 40 50
Shear strain s (%)

3
q=p'
2
1

0
1
2
3
Mean skeleton stress p' (kPa)
2.24

Overconsolidation R
Structure R*

3

Degree of saturation Sr (%)

Softening behavior with plastic volume
expansion above critical state line q=Mp’

Specific volume v (=1+e)□→● Softening behavior withplastic volume expansion above thecritical state line q=Mp‘, which is acharacteristic of Cam-clay model,
occurred, leading to a large
deformation.

w△→□ Overconsolidation andstructure were lost further, andsoftening behavior with plastic
volume compression due to the lossof structure occurred.

Pore water pressure p (kPa)○→△ The rise in the degree ofsaturation and pore pressure caused
plastic deformation and it caused
the loss of overconsolidation andstructure (increase in R and R*).

Deviator stress q (kPa)

Mechanical behavior of the soil element
at toe located on the slip line

2.23
2.22
2.21
0
1
2
3
Mean skeleton stress p' (kPa)

100
90
80
70
60
50

0

1

10 20 30 40 50
Shear strain s (%)
R R*

0.8
0.6
0.4
0.2
0

0

10 20 30 40 50
Shear strain s (%)

Analysis results (difference among 3 rain intensities)
Rainfallintensity

25 mm/ht = 182 min

50 mm/h

100 mm/ht = 91 min

t = 43 minExperiment0

t = 127 min

t = 67 min(%)
50

t = 36 min

Analysis

The tendency for theslip area to increase
with rainfall intensity
has been reproduced.

Shear strain
Pore water pressure

Experiment(kPa)

t = 127 min

t = 67 min

t = 36 min

Analysis53

The higher the rainfall
intensity, the higher thepore water pressure to
the top of the slope.

11

12

Application to a real problem(Atami embankment collapse)

13

Overview of Atami landslide
Location: Aizome River basin, Izuyama District, Atami City, Shizuoka PrefectureDate: July 3, 2021, around 10:30 a.m.

Embankment collapse at the head of Aizome River

Situation in Izuyama District, Atami City

Shizuoka Prefecture UAV photograph (July 3, 2021)

GSI aerial photograph (July 5, 2021)

54

14

Overview of Atami landslide
Rainfall conditions
24-hour rainfall:
Largest since 200948-hour rainfall:
Largest in recorded history
72-hour rainfall:
Largest in recorded history

Rainfall conditions up to the landslide(Atami Rainfall Observatory, Shizuoka Pref.)15

Overview of Atami landslide
Field survey of spring water points by drone
Spring always occurs
Spring occurs only when it rains

The collapse area is prone
to groundwater inflow
Distribution of spring sites (using orthophoto taken on September 10, 2021)

55

16

Analytical Cross Section
Assuming 2-D plane strain condition◆ Plan view around the collapsed area

433.85 m

C section was selected.
It connects boring Nos. 1, 5, 3, 4,
and the Aizome River valley area.

35.00 m410.83 m

50.00 m410.83 m

403.27 m
40.00 m10.00 m• Boring locations were selectedfrom the same perspective,
making it easier to use boring
results.

401.08 m
38.00 m400.67 m• C section can easily collectwater and become subject tosevere external force conditions.

21.00 m401.08 m
8.00 m17

Analytical Cross Section◆ Geological map of C section
(m)
450
B
Dt
An(D)
An(CL)

400

解析領域

An(CM)

2019年
地形
2021年
地形

Rd

An(D)
An(CL)
An(CM)

An(CL)

強風化安山岩溶岩
変質安山岩
弱風化安山岩溶岩

350

300
0

✓ The section consists of andesite An, slope sediments Dt, stream sediments Rd,
and upper and lower embankment B.
✓ The left end of the analysis section is the location of boring No. 1.
50

100

150

200

56

250

300

350

(m)

18

Hydraulic boundary condition
Rainfall boundary condition◆ From the time of embankment construction to subsequent steady state: 1,500 mm in 1 year (approx. 4 mm/day)◆ During failure simulation: 459 mm in 58 hours (approx. 8 mm/hour, approx. 190 mm/day)Andesite(An)Slope sediments (Dt)
Stream sediments (Rd)Upper embankment (B)Lower embankment (B)Groundwater upwelling conditions(only during failure simulation)

250 m3/day per unit depth vertically upward

flow rate

Constant head condition (head values distributed linearly corresponding to the water levels at left and right end)

In the July 1-3 failure simulation, conditions were set to supply a given flow ratefrom the bottom of the highly permeable stream sediments.

19

Soil parameters◆ Mechanical properties (elasto-plastic constitutive equation SYS Cam-clay model)• Upper and lower embankment: set based on mechanical tests of soil taken from the site.
• Other soil materials: set rigid conditions that are less prone to deformation
In the failure simulation, the condition that soil other than embankment is notdeformed is set.
◆ Hydraulic properties (hydraulic conductivity and soil water retention)• Determined based on in-situ permeability tests and soil water retention tests• For the lower embankment, two cases with different hydraulic properties were conducted
to determine the difference in deformation behavior.

57

Failure simulation (movie)
Shear strain(%)
and more

Change in water content(%)
and less

and more

20

21

100

20 40 60 80 100
Shear strain s (%)

100
98
96
94
0

20 40 60 80 100
Shear strain s (%)

w

20

s

Suction p (kPa)

30

10
0

0

20 40 60 80 100
Shear strain s (%)

q=p'

200

100

0
100
200
Mean skeleton stress p' (kPa)Specific volume v (=1+e)0Pore water pressure p (kPa)0

Deviator stress q (kPa)

Immediately before rainfall
At the time of sw = 100 %200w

Degree of saturation s (%)

Deviator stress q (kPa)

Failure simulation

2.30

CSL

NCL

2.20
2.10
0
100
200
Mean skeleton stress p' (kPa)

60
40
20
0
­20
0

20 40 60 80 100
Shear strain s (%)

Soil element output(Bottom of embankment)

High shear stress (stress ratio q/p’)
during embankment construction process
Groundwater inflow increases pore water pressure,decreases suction, and increases the degree of saturation.
Once the degree of saturation reaches 100 %, further water
absorption caused the increase in pore pressure and it causes
a decrease in mean effective stress and shear stress:
Softening behavior with plastic volume expansion above
q=Mp’

58

Summary of application to Atami embankment collapse

22State subjected to large shear forces (high stress ratio) due to construction of high embankment

Groundwater inflow
Saturation and decrease in effective stress (increase in stress ratio) due to water pressure rise

Water absorption (plastic volume expansion) and shear stress reduction (softening)

Softening with plastic volume expansion shown above the critical state line, a characteristic of the Cam-clay model

In this analysis, water absorption softening occurs upward from near the toe of theembankment, where water easily collects, sliding occurs where the embankment could
no longer resist the embankment load, eventually, the entire embankment collapsed.

59

Towards the Thought Process of Slope Disaster Prevention
in the Digital Era
20 Nov, 2023, IMI Auditorium, Kyushu Univ., Fukuoka, Japan

Geotechnical approaches forpreservation of openly exhibited Georelics damaged by rainfall infiltration
Mai Sawada
School of Environment and Society, Tokyo Institute ofTechnology, Japan
Excavated geo-relics are vulnerable to damage by natural processes. The aim of thisstudy is to contribute to the establishment of a technical framework for the preservationof openly exhibited geo-relics. This study also examines the preservation of an openly
exhibited geo-relic in Japan, which has experienced surface deformation in the soft soil
layer due to water infiltration. The surface deformation is numerically investigated by
performing seepage-deformation analyses based on unsaturated soil mechanics in orderto understand its mechanism and to obtain effective countermeasures. The results showthat deformation develops in the surface layer of the slope as the bonding between soil
particles, represented by skeleton stress, and decreases when water infiltrates the slope.
Although the calculation considers the influence of groundwater, as well as precipitation,
the results show that the deformation of the slope is primarily controlled by precipitation,
not by groundwater. Furthermore, the elevation of the groundwater does not contributeto the development of surface deformation. Based on the mechanism of the surface
deformation, replacing the surface layer with a well-compacted, highly permeable soil is
proposed to improve slope stability. It is predicted that this proposed method will beeffective because the replaced zone retains sufficient strength and stiffness when it is wet,
despite a decrease in the skeleton stress due to rainfall infiltration. This countermeasurehas been adopted for the actual restoration of a damaged slope.

References[1] Sawada, M. and Mimura, M. (2022). Geotechnical approaches for preservation of openly exhibited
Geo-relics damaged by rainfall infiltration. Soils and Foundations, 62(1), 101097.
[2] Agency for Cultural Affairs, Nara National Research Institute for Cultural Properties, Archeological
Institute of Kashihara Nara prefecture and Asuka Village Board of Education, 2017. Excavations reportin the Takamatsuzuka tumulus, 139-148. (in Japanese)61WS-3 Towards the Thought Process of Slope Disaster Prevention
in the Digital Era

Geotechnical approaches for preservation of openly
exhibited Geo-relics damaged by rainfall infiltration
Mai SAWADA, Dr. Eng
Assoc. prof, Tokyo Institute of Technology, Japan
Contact: sawada.m.af@m.titech.ac.jp

1

Introduction
Conservation and exhibition of geo­relics are becoming important
Remains of pillar

Reconstructed dwellings

Aerial photo of tombs

Mozu­Furuichi Kofun Group: Mounded Tombs ofAncient Japan (2019)

Jomon Prehistoric Sites in Northern Japan (2021)
https://bunka.nii.ac.jp/

62https://sannaimaruyama.pref.aomori.jp/about/iseki/2

Open exhibition
Open exhibitions are attractive, but they are easy to be damaged.
ExcavationRe­burying

Open exhibition
Outdoors

Indoors

Rainfall, wet­dry cycles,
freeze­thaw cycles, etc.

Desiccation cracking, salt
crystallization, fungi, etc.

3

Sakafuneishi Site (Asuka Village, Nara, Japan)
The slope deformation was caused by rainfall infiltration.
Sloped zone Flat zone
(5m×5m) (12m×12m)
Surface deformation

Water conduit

April, 2019463

Survey
Stone location
2019
2000

A­A’

Deformed zone
A

S­5
S­6

Wall

A’

• Stone location survey• Flat zone was stable• Sounding tests

SPT

Bank with a reinforced wallusing soil bags

1m

Soil profiles

5

(H)

(H

The slope had a soft surface
layer with N < 2
117

116
115
clay (N<2)

113clay­sand (N=2­4)

Soft
<2)
Softlayer
layer (N(N<2)

Elevation (m)
115

SWS

SWS

114
113

112

0

111

1

N=30–50

4

109

108

0

20

40

N­valueN-value

5

5

107

20

40

N­valueN-valueclay­sand (N=2­4)
clay­sand (N=4­10)
gravel (N=30­50)

64rock (N>50)

68

N=10–30910sand­fine gravel (N=10­30)
105

6

7

0

clay (N<2)

106
105

N=10–30

3
3

4

107

3

4

2

110
109

N=4–10

1

111

1

2

2

sand­fine gravel (N=10­30)

SPT

0

N=2–4

0

clay­sand (N=4­10)

gravel (N=30­50)

Reinforced wallusing soil bags

N>50
11

0

20

40

N­valueParcentage of finer (%)

Materials

Fc (%)

43

Dry density (g/cm3)

1.4

Permeability (m/s)

3.4×10­6

Failure stress ratio

1.31

Normalized shear modulus

67

100
90
80
70
60
50
40
30
20
10
0
0.001

Particle density: 2.73 g/cm3
Gravel: 2 %Sand: 49 %Silt: 16 %Clay: 27%

0.01

•
•
•
•

0.1
1
Grain size (mm)

10

100

Oedometer test
Water retention test
Permeability test
Constant suction triaxial test

7

Numerical simulation• 1 Oct – 31 Oct, 2017 (maximum rainfall intensity: 24 mm/h)• Seepage­deformation FE analysis• Elasto­plastic model based on skeleton stress (LIQCA2018)
Surface layer
Underlying layer
7.0°

Unit: m2.0

Groundwater

SPT

S­5

S­6

Wall

3.0
2.0

2.0
April, 2019

1.0
2.5

65

5.0

2.5

0.0

8

Degree of saturation
25
20

Groundwater level

15

4

Typhoon

3
2

10

1

5

0
0 1
Oct.

5 5
Oct.

10 10
Oct.

Oct. 1st

15 15
Oct.

2020
Oct.

25 25
Oct.

Oct. 15th

30 30
Oct.

0

Groundwater level(m)

Rainfall intensity(mm/h)

Degree of saturation began to increase before the typhoon.

Oct. 22nd

1m
90

91

92

93

94

95

96

97

98

99

100 (%)

9

Deformation
Computed deformation was qualitatively consistent with the measured values
1m

Deformation direction
Deformation direction

Elevation (m)
115

2019

114
113
2000

Deformation observed through survey

0

66

5

10

15

20

25

30

35

40

45

50 (cm)Computed deformation vectors

10Deviatoric plastic strain
25
20

15

4

TyphoonGroundwater level

3
2

10

1

5

0
0 1
Oct.

5 5
Oct.

10 10
Oct.

Oct. 1st

15 15
Oct.

2020
Oct.

Oct. 15th

0

30

60

90

120

25 25
Oct.

30 30
Oct.

0

Groundwater level(m)

Rainfall intensity(mm/h)

Degree of saturation began to increase before the typhoon.

Oct. 22nd

150 1801m

210 240 270 300 (%)

11

Mean skeleton stress
25
20

15

4

TyphoonGroundwater level

3
2

10

1

5

0
0 1
Oct.

5 5
Oct.

10 10
Oct.

Oct. 1st

15 15
Oct.

2020
Oct.

Oct. 15th

0

10

20

30

40

25 25
Oct.

30 30
Oct.

0

Groundwater level(m)

Rainfall intensity(mm/h)

Suction­induced strength decreased as the degree of saturation increased.

Oct. 22nd

50

60

70

80

90

100 (kPa)

1m

12

67

Restoration proposal• Lowering groundwater level was not effective• Replacement of the soft surface soil
• Densely compacted permeable sandy soil improves slope stability

13

Replacement soil
Original

Replacement

Fc (%)

43

16

Dry density (g/cm3)

1.4

1.7

Permeability (m/s)

3.4×10­6

1.5×10­4

Failure stress ratio

1.31

1.55

Normalized shear
modulus

67

236

100

Parcentage of finer (%)

90
80

Original

70
60
50
40
30
20

Replacement

10

0
0.001

0.01

0.1
1
Grain size (mm)

10

100

14

68

Restored slope –Mean skeleton stress–
25
20

15

4

TyphoonGroundwater level

3
2

10

1

5

0
0 1
Oct.

5 5
Oct.

10 10
Oct.

Oct. 1st

15 15
Oct.

2020
Oct.

Oct. 15th

0

10

20

30

40

25 25
Oct.

30 30
Oct.

0

Groundwater level(m)

Rainfall intensity(mm/h)

Suction­induced strength decreased in the restored slope.

Oct. 22nd

50

60

70

80

90

1m

100 (kPa)

15

Restored slope –Deviatoric plastic strain–
25
20

15

4

TyphoonGroundwater level

3
2

10

1

5

0
0 1
Oct.

5 5
Oct.

10 10
Oct.

Oct. 1st

15 15
Oct.

Oct. 15th

0

30

60

90

120

2020
Oct.

25 25
Oct.

30 30
Oct.

0

Groundwater level(m)

Rainfall intensity(mm/h)The restored slope was stable when it was wet and mean skeleton stress decreased.

Oct. 22nd

150 180

210 240 270 300 (%)

1m

16

69

Conclusions◼ The slope deformation developed in the soft surface layer with N<2. We need toensure an understanding of field investigations in geo-relics by demonstrating theirimportance through case studies.
◼ The damage mechanism investigation and restoration proposal were conductedbased on simulation results. The deformation was caused by a reduction in thesuction-induced stiffness and strength. The slope was restored by replacing thesurface soil with densely compacted permeable soil.
◼ The quantitative evaluation enables the discussion of the restoration of open
exhibits of geo-relics from the perspectives of both archeological authenticity andgeotechnical validity.
1770

MI レクチャーノートシリーズ刊行にあたり
本レクチャーノートシリーズは、文部科学省 21 世紀 COE プログラム「機能数理学の構築と展開」（H15-19 年度）において作成した COE Lecture Notesの続刊であり、文部科学省大学院教育改革支援プログラム「産業界が求める数学博士と新修士養成」（H19-21 年度）および、同グローバル COE プログラ
ム「マス・フォア・インダストリ教育研究拠点」（H20-24 年度）において行われた講義の講義録として出版されてきた。平成 23 年 4 月のマス・フォア・イ
ンダストリ研究所（IMI）設立と平成 25 年 4 月の IMI の文部科学省共同利用・共同研究拠点として「産業数学の先進的・基礎的共同研究拠点」の認定を受け、今後、レクチャーノートは、マス・フォア・インダストリに関わる国内外の研究者による講義の講義録、会議録等として出版し、マス・フォア・インダ
ストリの本格的な展開に資するものとする。
2022 年 10 月
マス・フォア・インダストリ研究所
所長

梶原 健司

2023年度採択分 九州大学マス・フォア・インダストリ研究所 共同利用研究集会

デジタル化時代に求められる斜面防災の思考法
発
編
発

行
集
行

2024年 3 月 18 日
澤
 田茉伊
九州大学マス・フォア・インダストリ研究所
九州大学大学院数理学府〒819-0395 福岡市西区元岡744
九州大学数理・IMI 事務室
TEL 092-802-4402 FAX 092-802-4405
URL https://www.imi.kyushu-u.ac.jp/

印

刷

城島印刷株式会社〒810-0012 福岡市中央区白金 2 丁目 9 番 6 号
TEL 092-531-7102 FAX 092-524-4411

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多重ゼータ値入門

February 15, 2010

COE Lecture Note Vol.24

Fulton B.Gonzalez

Notes on Integral Geometry and Harmonic Analysis

COE Lecture Note Vol.25

Wayne Rossman

Discrete Constant Mean Curvature Surfaces via Conserved Quantities
130pages

May 31, 2010

COE Lecture Note Vol.26

Mihai Ciucu

Perfect Matchings and Applications

July 2, 2010

徹
正行
健司
英一
康秀

111pages

66pages

125pages

March 12, 2010

シリーズ既刊
Issue

Author／Editor

Title

Published

COE Lecture Note Vol.27

九州大学大学院
数理学研究院

Forum “Math-for-Industry” and Study Group Workshop
Information security, visualization, and inverse problems, on the basisof optimization techniques 100pages

October 21, 2010

COE Lecture Note Vol.28

ANDREAS LANGERMODULAR FORMS, ELLIPTIC AND MODULAR CURVESLECTURES AT KYUSHU UNIVERSITY 2010 62pages

November 26, 2010

COE Lecture Note Vol.29

木田 雅成
原田 昌晃
横山 俊一

Magma で広がる数学の世界

December 27, 2010

COE Lecture Note Vol.30

原
松井
廣島

Mathematical Quantum Field Theory and Renormalization Theory
201pages

January 31, 2011

COE Lecture Note Vol.31

若山 正人
福本 康秀
高木
剛
山本 昌宏

Study Group Workshop 2010 Lecture & ReportFebruary 8, 2011

COE Lecture Note Vol.32

Institute of Mathematics
for Industry,
Kyushu University

Forum “Math-for-Industry” 2011
“TSUNAMI-Mathematical Modelling”
Using Mathematics for Natural Disaster Prediction, Recovery andProvision for the Future 90pages

September 30, 2011

COE Lecture Note Vol.33

若山 正人
福本 康秀
高木
剛
山本 昌宏

Study Group Workshop 2011 Lecture & Report

October 27, 2011

COE Lecture Note Vol.34

Adrian Muntean
Vladimír Chalupecký

Homogenization Method and Multiscale Modeling

COE Lecture Note Vol.35

横山 俊一
夫
紀恵
林
卓也

計算機代数システムの進展

COE Lecture Note Vol.36

Michal Beneš
Masato Kimura
Shigetoshi Yazaki

Proceedings of Czech-Japanese Seminar in Applied Mathematics 2010
107pages

COE Lecture Note Vol.37

若山 正人
高木
剛
Kirill Morozov
平岡 裕章
木村 正人
白井 朋之
西井 龍映
栄 伸一郎
穴井 宏和
福本 康秀

平成23年度 数学・数理科学と諸科学・産業との連携研究ワーク February 20, 2012
ショップ 拡がっていく数学 ～期待される “見えない力” ～154pages隆
卓
文生

157pages

128pages

140pages

72pages

210pages

October 28, 2011

November 30, 2011

January 27, 2012

シリーズ既刊
Issue

Author／Editor

Title

Published

COE Lecture Note Vol.38

Fumio Hiroshima
Itaru Sasaki
Herbert Spohn
Akito Suzuki

Enhanced Binding in Quantum Field Theory

COE Lecture Note Vol.39

Institute of Mathematics
for Industry,
Kyushu University

Multiscale Mathematics: Hierarchy of collective phenomena andinter­relations between hierarchical structures 180pages

March 13, 2012

COE Lecture Note Vol.40

井ノ口順一
太田 泰広
筧
三郎
梶原 健司
松浦
望

離散可積分系・離散微分幾何チュートリアル2012

March 15, 2012

COE Lecture Note Vol.41

Institute of Mathematics
for Industry,
Kyushu University

Forum “Math-for-Industry” 2012
“Information Recovery and Discovery”

COE Lecture Note Vol.42

佐伯
若山
山本

Study Group Workshop 2012 Abstract, Lecture & Report

178pages

November 19, 2012

COE Lecture Note Vol.43

Institute of Mathematics
for Industry,
Kyushu University

Combinatorics and Numerical Analysis Joint Workshop

103pages

December 27, 2012

COE Lecture Note Vol.44

萩原学

モダン符号理論からポストモダン符号理論への展望

107pages

January 30, 2013

COE Lecture Note Vol.45

金山

寛

Joint Research Workshop of Institute of Mathematics for Industry(IMI), Kyushu University“Propagation of Ultra-large-scale Computation by the Domaindecomposition-method for Industrial Problems (PUCDIP 2012)”
121pages

February 19, 2013

COE Lecture Note Vol.46

西井 龍映
栄 伸一郎
岡田 勘三
落合 啓之
小磯 深幸
斎藤 新悟
白井 朋之

科学・技術の研究課題への数学アプローチ―数学モデリングの基礎と展開― 325pages

February 28, 2013

COE Lecture Note Vol.47

SOO TECK LEE

BRANCHING RULES AND BRANCHING ALGEBRAS FOR THE
COMPLEX CLASSICAL GROUPS 40pages

March 8, 2013

COE Lecture Note Vol.48

溝口
脇
平坂
谷口
島袋

博多ワークショップ「組み合わせとその応用」 124pages

March 28, 2013

修
正人
昌宏

佳寛
隼人
貢
哲至
修

204pages

March 12, 2012

152pages

October 22, 2012

91pagesシリーズ既刊
Issue

Author／Editor

COE Lecture Note Vol.49

照井
小原
濱田
横山
穴井
横田

MI Lecture Note Vol.50

章
功任
龍義
俊一
宏和
博史

Title

Published

マス・フォア・インダストリ研究所 共同利用研究集会 II
数式処理研究と産学連携の新たな発展 137pages

August 9, 2013

Ken Anjyo
Hiroyuki Ochiai
Yoshinori Dobashi
Yoshihiro Mizoguchi
Shizuo Kaji

Symposium MEIS2013:
Mathematical Progress in Expressive Image Synthesis

October 21, 2013

MI Lecture Note Vol.51

Institute of Mathematics
for Industry, Kyushu
University

Forum “Math-for-Industry” 2013
“The Impact of Applications on Mathematics”

MI Lecture Note Vol.52

佐伯
岡田
髙木
若山
山本

Study Group Workshop 2013 Abstract, Lecture & Report
142pages

November 15, 2013

MI Lecture Note Vol.53

四方 義啓
櫻井 幸一
安田 貴徳
Xavier Dahan

平成25年度 九州大学マス・フォア・インダストリ研究所
共同利用研究集会 安全・安心社会基盤構築のための代数構造～サイバー社会の信頼性確保のための数理学～ 158pages

December 26, 2013

MI Lecture Note Vol.54

Takashi Takiguchi
Hiroshi Fujiwara

Inverse problems for practice, the present and the future

January 30, 2014

MI Lecture Note Vol.55

栄 伸一郎
溝口 佳寛
脇
隼人
渋田 敬史

Study Group Workshop 2013 数学協働プログラム Lecture & Report
98pages

February 10, 2014

MI Lecture Note Vol.56

Yoshihiro Mizoguchi
Hayato Waki
Takafumi Shibuta
Tetsuji Taniguchi
Osamu Shimabukuro
Makoto Tagami
Hirotake Kurihara
Shuya Chiba

Hakata Workshop 2014
~ Discrete Mathematics and its Applications ~March 28, 2014

MI Lecture Note Vol.57

Institute of Mathematics
for Industry, Kyushu
University

Forum “Math-for-Industry” 2014:“Applications + Practical Conceptualization + Mathematics = fruitful
Innovation” 93pages

October 23, 2014

MI Lecture Note Vol.58

安生健一
落合啓之

Symposium MEIS2014:
Mathematical Progress in Expressive Image Synthesis

November 12, 2014

修
勘三
剛
正人
昌宏

154pages

October 30, 2013

97pages

93pages

141pages

135pagesシリーズ既刊
Issue

Author／Editor

MI Lecture Note Vol.59

西井
岡田
梶原
髙木
若山
脇
山本

龍映
勘三
健司
剛
正人
隼人
昌宏

MI Lecture Note Vol.60

西浦博

MI Lecture Note Vol.61

Title

Published

Study Group Workshop 2014 数学協働プログラム
Abstract, Lecture & Report 196pages

November 14, 2014

平成26年度九州大学 IMI 共同利用研究・研究集会（I）
感染症数理モデルの実用化と産業及び政策での活用のための新たな展開 120pages

November 28, 2014

溝口 佳寛
Jacques Garrigue
萩原
学
Reynald Affeldt

研究集会
高信頼な理論と実装のための定理証明および定理証明器
Theorem proving and provers for reliable theory and implementations(TPP2014) 138pages

February 26, 2015

MI Lecture Note Vol.62

白井朋之

Workshop on “β-transformation and related topics”

March 10, 2015

MI Lecture Note Vol.63

白井朋之

Workshop on “Probabilistic models with determinantal structure”
107pages

August 20, 2015

MI Lecture Note Vol.64

落合
土橋

啓之
宜典

Symposium MEIS2015:
Mathematical Progress in Expressive Image Synthesis

September 18, 2015

MI Lecture Note Vol.65

Institute of Mathematics
for Industry, Kyushu
University

Forum “Math-for-Industry” 2015
“The Role and Importance of Mathematics in Innovation”

MI Lecture Note Vol.66

岡田 勘三
藤澤 克己
白井 朋之
若山 正人
脇
隼人
Philip Broadbridge
山本 昌宏

Study Group Workshop 2015 Abstract, Lecture & Report
156pages

MI Lecture Note Vol.67

Institute of Mathematics
for Industry, Kyushu
University

IMI-La Trobe Joint Conference“Mathematics for Materials Science and Processing”
66pages

February 5, 2016

MI Lecture Note Vol.68

古庄
小谷
新甫

英和
久寿
洋史

結び目と Grothendieck-Teichmüller 群
116pages

February 22, 2016

MI Lecture Note Vol.69

土橋
鍛治

宜典
静雄

Symposium MEIS2016:
Mathematical Progress in Expressive Image Synthesis

MI Lecture Note Vol.70

Institute of Mathematics
for Industry,
Kyushu University

Forum “Math-for-Industry” 2016
“Agriculture as a metaphor for creativity in all human endeavors”
98pagesNovember 2, 2016

MI Lecture Note Vol.71

小磯
二宮
山本

Study Group Workshop 2016 Abstract, Lecture & Report

November 21, 2016

深幸
嘉行
昌宏

59pages

124pages

74pages

October 23, 2015

November 5, 2015

82pages

143pages

October 24, 2016

シリーズ既刊
Issue

Author／Editor
朝雄
泉
文生

Title

Published

MI Lecture Note Vol.72

新井
小嶋
廣島

MI Lecture Note Vol.73

穴田 啓晃
Kirill Morozov
須賀 祐治
奥村 伸也
櫻井 幸一

Secret Sharing for Dependability, Usability and Security of Network
Storage and Its Mathematical Modeling 211pages

March 15, 2017

MI Lecture Note Vol.74

QUISPEL, G. Reinout W.
BADER, Philipp
MCLAREN, David I.
TAGAMI, Daisuke

IMI-La Trobe Joint Conference
Geometric Numerical Integration and its Applications

March 31, 2017

MI Lecture Note Vol.75

手塚
田上
山本

Study Group Workshop 2017 Abstract, Lecture & Report

MI Lecture Note Vol.76

宇田川誠一

Tzitzéica 方程式の有限間隙解に付随した極小曲面の構成理論―Tzitzéica 方程式の楕円関数解を出発点として― 68pages

August 4, 2017

MI Lecture Note Vol.77

松谷 茂樹
佐伯
修
中川 淳一
田上 大助
上坂 正晃
Pierluigi Cesana
濵田 裕康

平成29年度 九州大学マス・フォア・インダストリ研究所
共同利用研究集会（I）
結晶の界面，転位，構造の数理 148pages

December 20, 2017

MI Lecture Note Vol.78

瀧澤 重志
小林 和博
佐藤憲一郎
斎藤
努
清水 正明
間瀬 正啓
藤澤 克樹
神山 直之

平成29年度 九州大学マス・フォア・インダストリ研究所
プロジェクト研究 研究集会（I）
防災・避難計画の数理モデルの高度化と社会実装へ向けて
136pages

February 26, 2018

MI Lecture Note Vol.79

神山
畔上

平成29年度 AIMaP チュートリアル
最適化理論の基礎と応用 96pages

February 28, 2018

MI Lecture Note Vol.80

Kirill Morozov
Hiroaki Anada
Yuji Suga

IMI Workshop of the Joint Research Projects
Cryptographic Technologies for Securing Network Storage
and Their Mathematical Modeling 116pages

March 30, 2018

MI Lecture Note Vol.81

Tsuyoshi Takagi
Masato Wakayama
Keisuke Tanaka
Noboru Kunihiro
Kazufumi Kimoto
Yasuhiko Ikematsu

IMI Workshop of the Joint Research Projects
International Symposium on Mathematics, Quantum Theory,
and Cryptography 246pages

September 25, 2019

MI Lecture Note Vol.82

池森

令和 2 年度 AIMaP チュートリアル
新型コロナウイルス感染症にかかわる諸問題の数理
145pages

March 22, 2021

集
大助
昌宏

直之
秀幸

俊文

Mathematical quantum field theory and related topics

133pages

71pages

118pages

January 27, 2017

October 20, 2017

シリーズ既刊
Issue

Author／Editor

Title

Published

MI Lecture Note Vol.83

早川健太郎
軸丸 芳揮
横須賀洋平
可香谷 隆
林
和希
堺
雄亮

シェル理論・膜理論への微分幾何学からのアプローチとその建築曲面設計への応用 49pages

July 28, 2021

MI Lecture Note Vol.84

Taketoshi Kawabe
Yoshihiro Mizoguchi
Junichi Kako
Masakazu Mukai
Yuji Yasui

SICE-JSAE-AIMaP Tutorial
Advanced Automotive Control and Mathematics

December 27, 2021

MI Lecture Note Vol.85

Hiroaki Anada
Yasuhiko Ikematsu
Koji Nuida
Satsuya Ohata
Yuntao Wang

IMI Workshop of the Joint Usage Research Projects
February 9, 2022
Exploring Mathematical and Practical Principles of Secure Computationand Secret Sharing 114pages

MI Lecture Note Vol.86

濱田 直希
穴井 宏和
梅田 裕平
千葉 一永
佐藤 寛之
能島 裕介
加葉田雄太朗
一木 俊助
早野 健太
佐伯
修

2020年度採択分 九州大学マス・フォア・インダストリ研究所
共同利用研究集会
進化計算の数理 135pages

February 22, 2022

MI Lecture Note Vol.87

Osamu Saeki,
Ho Tu Bao,
Shizuo Kaji,
Kenji Kajiwara,
Nguyen Ha Nam,
Ta Hai Tung,
Melanie Roberts,
Masato Wakayama,
Le Minh Ha,
Philip Broadbridge

Proceedings of Forum “Math-for-Industry” 2021
-Mathematics for Digital Economy- 122pages

March 28, 2022

MI Lecture Note Vol.88

Daniel PACKWOOD
Pierluigi CESANA,
Shigenori FUJIKAWA,
Yasuhide FUKUMOTO,
Petros SOFRONIS,Alex STAYKOVPerspectives on Artificial Intelligence and Machine Learning inMaterials Science, February 4-6, 2022 74pages

November 8, 2022

110pagesシリーズ既刊
Issue

Author／Editor

Title

Published

MI Lecture Note Vol.89

松谷 茂樹
落合 啓之
井上 和俊
小磯 深幸
佐伯
修
白井 朋之
垂水 竜一
内藤 久資
中川 淳一
濵田 裕康
松江
要
加葉田雄太朗2022年度採択分 九州大学マス・フォア・インダストリ研究所
共同利用研究集会
材料科学における幾何と代数 III 356pages

December 7, 2022

MI Lecture Note Vol.90

中山
谷川
品野
近藤
石原
鍛冶
藤澤

尚子
拓司
勇治
正章
亨
静雄
克樹

2022年度採択分 九州大学マス・フォア・インダストリ研究所
共同利用研究集会
データ格付けサービス実現のための数理基盤の構築 58pages

December 12, 2022

MI Lecture Note Vol.91

Katsuki Fujisawa
Shizuo Kaji
Toru Ishihara
Masaaki Kondo
Yuji Shinano
Takuji Tanigawa
Naoko Nakayama

IMI Workshop of the Joint Usage Research Projects
Construction of Mathematical Basis for Realizing Data Rating Service
610pages

December 27, 2022

MI Lecture Note Vol.92

丹田
三宮
廣島

2022年度採択分 九州大学マス・フォア・インダストリ研究所
共同利用研究集会
時間・量子測定・準古典近似の理論と実験〜古典論と量子論の境界〜 150pages

Janualy 6, 2023

MI Lecture Note Vol.93

Philip Broadbridge
Luke Bennetts
Melanie Roberts
Kenji Kajiwara

Proceedings of Forum “Math-for-Industry” 2022
-Mathematics of Public Health and Sustainability-

June 19, 2023

MI Lecture Note Vol.94

國廣
池松
伊豆
穴田
縫田

2023年度採択分 九州大学マス・フォア・インダストリ研究所
共同利用研究集会
現代暗号に対する安全性解析・攻撃の数理 260pages

Janualy 11, 2024

MI Lecture Note Vol.95

Osamu Saeki
Wojciech Domitrz
Stanisław Janeczko
Marcin Zubilewicz
Michał Zwierzyński

International Project Research-Workshop (I)WORKSHOP on Mathematics for Industry 364pages

March 14, 2024

聡
俊
文生

昇
泰彦
哲也
啓晃
光司

170pages九州大学マス・フォア・インダストリ研究所

九州大学大学院 数理学府
URL https://www.imi.kyushu-u.ac.jp/