Transcript Document

Microzonation Study of Soil
Liquefaction Potential and
Damage
Wei F. Lee
Taiwan Construction Research Institute
Ming-Hung Chen
National Center for Research on
Earthquake Engineering
Problems and Solutions

Liquefaction microzonation in
metropolitan Area
• Sensitivity- adequate analysis unit
• Population- building coverage
• Foundation type

GIS application
Southwest Taiwan Liquefaction
Potential Microzonation
ISSMFE TC4，1993
Grade
I
Data Based
Historic data
Geology map
Surface map
II
Aerial photo
Subsurface condition
Ground surveying
III
Geotechnical
Investigation
Zonation
Procedure
Level One
Geological
Environmental
Topography and
Surface condition
Grid Generation
Ⅰ
Ⅱ
Ⅲ
Procedure
Level Two
Influence Factor
Selection
Data Collection
Level Three
In-Situ/ Lab soil Properties
Liquefaction Potential Evaluation and Risk
Analysis
Grid Setup

Structure Coverage Rate
Structure Coverage Rate
Grid Size
Below 25﹪
1600×1600 m2
25﹪~ 60﹪
800×800 m2
Above 60﹪
400×400 m2
GIS Application
GIS Combined Slope Management
Database
GIS Evaluation
地形圖
數值地形模型
Topographic map
Digitalized models
地質圖
Geological
map
地質圖
Geological
zonation
Geophysics
Info.
地質構造圖
Strike
and fault map
岩石節理及方向
Hydraulic system
map
水系圖
River system
Past event record
categorization
現場調查訪問
、
相關單位已有之
歷史災害資料
歷次災害
分布圖
權重
Weighting
system
水系圖
評估單元
的風險率
Case Studied

Level I assessment
• Kaohsiung City

Level I, II and III, with initial hazard
analysis
• Taipei City

Evaluation method
• Yuan Lin Township
Kaohsiung City
Kaohsiung Liquefaction Potential Microzonation
Regular
Grid
Kaohsiung Liquefaction Potential Microzonation
Modified
grid
Kaohsiung Liquefaction Potential Microzonation
Level OneRegular grid
Southwest Taiwan Liquefaction Potential
Microzonation
Level OneModified grid
Kaohsiung Liquefaction Potential Microzonation
Third Level (Seed97)－
Regular Grid
Kaohsiung Liquefaction Potential Microzonation
Third Level (T&Y)Modified Grid
Taipei City
Microzonation Grid
Regular Method
Microzonation Grid
Modified Method
Hydraulic Map and Administration
Taipei Basin First Class Evaluation
Second Class Evaluation
2002 Ground Water
Second Class Evaluation
Geology
Third Class Evaluation
SPT Boring Locations
Seed97 Liquefaction Potential
Evaluation (Dry Season)
Dry Season
Regular
Dry Season
Modified
Microzonation
Regular
Mocrozonation
Wet Season
Comparison of indirect interpretation and
proposed method
Settlement Evaluation, (Seed97 method,
dry season, Regular Microzonation)
Lateral Spreading Evaluation
(Bartlett and Youd, EQ Source B, dry season, Regular Microzonation)
Lateral Spreading Evaluation
(Bartlett and Youd, EQ Source A, dry season, Regular Microzonation)
Analysis Tool
NNT Evaluation
Yuan Lin
Artificial Neural Network (ANN)
Database including 279 cases
80% for training
20% for testing
•Non-Liquefied cases 237
•Liquefied cases 42
液化土層數(42)
非液化土層數(237)
8
48
訓練(80%)
測試(20%)
訓練(80%)
測試(20%)
189
34
Selected Input Factors
1. Depth of liquefiable soil
2. SPT-N value
3. Fines Content (FC)
4. Total Stress
5. Effective Stress
6. D50
7. Peak Horizontal Acceleration（amax）
8. Earthquake Magnitude（Mw）
9. Liquefaction Initiation Evaluation
Artificial Neural Network
•Hidden Level：2
•Note：10 moving note structure (Wu,1991)
•Connection ：Fully Connection
•Weighting（Wij）：Quickprop (Fahlman，1988）
ANN-1 Model
Soil Properties
Liquefaction Potential
ANN-1 model Input and Output
網路模式
ANN-1
輸入參數
Input
輸出層參數
SL
N
(N1)60 FC
σ’
Rρ
D50
A
●
●
●
●
●
● 液化指標
B
●
●
●
●
●
液化指標
C
●
●
●
●
●
● 液化指標
D
●
●
●
●
●
液化指標
Output
Data Normalizing
SL
23.8000 2.4218
2.9000
0.2172
2
1.6320
1.0000
0.0033
0.1966
30
99
30
2.5
10
0.5898
1
0
1
1
0.0001
0.0248
FC
29
99
極小值
2
第 極大值
第 極大值
σ’
D50
N
Rρ
一
組
二
極小值
組
amax
Mw
MSF
SL
極大值
0.5g
8
2.8235
0.5898
極小值
0.07g
5
0.8477
0.0248
ANN-2 Model
Soil Properties
Critical State Cyclic Resistance
Ratio (CRR)
ANN-2 model Input and Output
輸入參數 Input
網路模式
ANN-2
N
(N1)60 FC
σ’
Rρ
D50
A
●
●
●
●
●
B
●
●
●
●
C
●
●
●
●
D
●
●
●
●
輸出層參數
Output
CRRANN
CRRANN
●
CRRANN
CRRANN
ANN Results
ANN-1 model
組別 型別
ANN-2 model
液化成
功率
非液化
成功率
總成功 液化成功 非液化
率
率
成功率
總成功
率
第
A
75.0﹪
97.9﹪
94.6﹪
100.0﹪ 0.4﹪
15.4﹪
一
B
62.5﹪
97.9﹪
92.9﹪
100.0﹪ 3.4﹪
18.0﹪
組
C
50.0﹪
97.9﹪
91.1﹪
100.0﹪ 3.4﹪
18.0﹪
D
75.0﹪
97.9﹪
94.6﹪
100.0﹪ 3.8﹪
18.3﹪
第
A
62.5﹪
97.9﹪
92.9﹪
50.0﹪
74.7﹪
71.0﹪
二
B
75.0﹪
97.9﹪
94.6﹪
71.5﹪
82.3﹪
80.7﹪
組
C
75.0﹪
95.8﹪
92.9﹪
64.3﹪
84.0﹪
81.0﹪
D
75.0﹪
97.9﹪
94.6﹪
71.5﹪
81.4﹪
79.9﹪
8
48
56
42
237
279
測試土層總
數
Critical State
求取 Critical-state 時各型別所得之資料數
組別 型別
1
2
3
4
5
總資料
數
第
A
13
195
79
39
158
484
一
B
2
143
90
50
63
348
組
C
11
187
106
61
141
506
D
8
159
118
50
81
416
第
A
2
192
78
40
117
429
二
B
23
199
112
77
192
603
組
C
18
172
80
55
155
480
D
83
133
77
100
165
558
Future Research


More boring?
Visualized Iwasaki method?
• Soil maps at different depth




Geophysics Measurement
Analysis Tool
Metropolitan Geotech Database
(MGD)
One more big one!
Thank You
Questions