Course Outline (1)
CE03.98N
Soil Dynamics and Earthquake Engineering
#1 Introduction
1.
Introduction
1.1 Earthquakes
1.2 Consequences of Earthquakes
2.
Engineering Seismology
2.1 Mechanism of Earthquakes
2.2 Seismic Waves
2.3 Earthquake Magnitude and Seismic Intensity
2.4 Seismometers and Seismic Observation
2.5 Tsunamis
3.
Seismic Ground Motion
3.1 Characteristics of Seismic Ground Motion
3.2 Fourier Spectrum
3.3 Response Spectrum
3.4 Attenuation Relations and Effects of Soil Conditions
3.5 Microtremor Observation
January 8, 2003
Fumio Yamazaki
yamazaki@ait.ac.th
http://www.sce.ait.ac.th/people/faculty/~yamazaki
STE/SCE, AIT.
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Class Schedule
Course Outline (2)
4. Seismic Hazard and Seismic Risk
4.1 Seismic Hazard Analysis
4.2 Damage Assessment
By Prof. F. Yamazaki
5.
By Prof. P.K. Basudhar
Dynamic Soil Properties
5.1 Measurement of Dynamic Soil Properties
5.2 Stress-Strain Behaviors
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6. Wave Propagation and Ground Response Analysis
6.1 Wave Propagation
6.2 One-Dimensional Ground Response Analysis
7. Liquefaction and Slope Stability
7.1 Liquefaction
7.2 Slope Stability
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1) 8 January Lecture: Introduction, Engineering Seismology
(1)
2) 15 January Lecture: Engineering Seismology (2)
3) 22 January Lecture: Seismic Ground Motion (1)
4) 29 January Lecture: Seismic Ground Motion (2)
5) 5 February Lecture: Seismic Hazard and Seismic Risk
12 February Midterm Exam
6) 19 February Lecture:
7) 26 February Lecture:
To be announced
8) 5 March Lecture:
9) 12 March Lecture:
10) 19 March Lecture:
11) 26 March Lecture:
2 April Final Exam
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Grading System
References
The Final grade will be computed according to the
following weight distribution:
Mid-Term Exam 40%
Final Exam 40%
Assignments 20%
Textbook:
Lecture Notes (PPT), available on the AIT Web site
Reference Book:
S. L. Krammer: Geotechnical Earthquake Engineering,
Prentice Hall, 1996
Closed-book examinations are given both in the midterm and finals.
Reference Web Page:
For seismology, http://earthquake.usgs.gov/
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Basic earthquake terms
What is an earthquake?
Hypocenter (Focus): The hypocenter is the
Earthquake:
Earthquake is a term used to describe both sudden slip on a fault,
and the resulting ground shaking and radiated seismic energy
caused by the slip, or by volcanic or magmatic activity, or other
sudden stress changes in the earth.
point within the earth where an earthquake
rupture starts.
Epicenter: The epicenter is the point on the
earth's surface vertically above the hypocenter.
Focal Depth: The focal depth refers to the
depth of an earthquake hypocenter.
Seismogram: A seismogram
is a record written by a
seismograph in response to
ground motions produced by
an earthquake, explosion, or
other ground-motion sources
Fault Plane: The fault plane is the planar (flat)
surface along which there is slip during an
earthquake.
Magnitude: The magnitude is a number that
characterizes the relative size of an earthquake.
http://earthquake.usgs.gov/image_glossary/
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http://earthquake.usgs.gov/image_glossary/
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Where do earthquakes occur ?
http://neic.usgs.gov/neis/general/seismicity/world.html
Ring of Fire
(the Circum-Pacific
belt )
The "Ring of Fire“ is the zone of earthquakes surrounding the Pacific Ocean,
about 90% of the world's earthquakes occur there. The next most seismic
region (5-6% of earthquakes) is the Alpide belt (extends from Mediterranean
region, eastward through Turkey, Iran, and northern India.
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http://earthquake.usgs.gov/image_glossary/
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Plate Tectonics and Earthquakes
Regional
Seismicity
http://neic.usgs.gov/neis/general/
seismicity/seismicity.html
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Earthquake Hazard and Risk
Earthquake Hazard Map
Earthquake hazard:
G
LOBAL
S
EISMIC
H
AZARD
A
P
SSESSMENT
ROGRAM
Earthquake hazard is anything associated
with an earthquake that may affect the
normal activities of people. This includes
surface faulting, ground shaking,
landslides, liquefaction, tectonic
deformation, tsunamis, and seiches.
Earthquake risk:
Seismicity of USA 1977 - 1997
Earthquake risk is the probable damage,
and number of people that are expected to
be hurt or killed if a likely earthquake on a
particular fault occurs.
http://earthquake.usgs.gov/image_glossary/
http://seismo.ethz.ch/gshap
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/
1.2 Consequences of Earthquakes
¾Geological hazard
surface faulting, landslides, liquefaction
Nature
(Hazard
)
http://neic.usgs.gov/neis/general/seismicity/us.html
Hazard map
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Fault Rupture in the
1999 Chi-Chi,
Taiwan EQ
¾Tsunamis
¾Structural damages
buildings, bridges, lifelines (roads, water systems)
Built
Environment
¾Fires
¾Human casualty
¾Socio-economic impacts
Social World
(Risk)
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The Gujarat, India EQ on January 26, 2001
Bridges and Buildings after
the 1995 Kobe EQ
MJ=7.2
Ms=7.5
Urban Area
Rural Housing
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Railways after the Kobe EQ
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Damage to Lifelines and Fire Following EQ
the 1994 Northridge EQ
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the 1995 Kobe EQ
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Sand boil and settlement in Kobe
Port Island after the Kobe EQ
Liquefaction
Ground failures associated
with liquefaction
¾Sand boils and water spouting
¾Ground subsidence
¾Loss of bearing capacity
¾Floating up of underground structures
¾Lateral spreads
The 1964 Niigata EQ, Japan
Before
earthquake
During
earthquake
During
liquefaction
Uplift of a manhole due to liquefaction
in the 1993 Kushiro-Oki EQ
After
earthquake
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Tsunami disaster
Loss of bearing capacity
A building in Dagupan,
Philippines after the 1990
Luzon EQ
Complete devastation….
RC structure remain
Overturned building in
Adpazari, Turkey in the
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1999 Kocaeli EQ
Okushiri Island after the 1993
Hokkaido-Nansei-Oki EQ
A burned boat. Cause of
fire?
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Elastic Rebound Theory - Reid 1910
2. Engineering Seismology
An earthquake is caused by the rebound of elastically
strained rock; From the observation of 1906 San Francisco EQ
2.1 Mechanism of Earthquakes
2.2 Seismic Waves
2.3 Earthquake Magnitude and Seismic Intensity
2.4 Seismometers and Seismic Observation
2.5 Tsunamis
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Plate Tectonics
http://www.seismo.unr.edu/ftp/pub/louie/class/100/seismic-waves.html
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Crust, Mantle and Lithosphere
Plate Tectonics is the theory supported by a wide range of evidence that
considers the earth's crust and upper mantle to be composed of several large,
thin, relatively rigid plates that move relative to one another.
The crust is the outermost major layer of the
earth, ranging from about 10 to 65 km in
thickness worldwide. The uppermost 15-35
km of crust is brittle enough to produce
earthquakes.
The mantle is the part of the earth's interior
between the metallic outer core and the crust.
The lithosphere is the outer solid part of the
earth, including the crust and uppermost
mantle. The lithosphere is about 100 km
thick.The lithosphere below the crust is
brittle enough at some locations to produce
earthquakes by faulting, such as within a
subducted oceanic plate.
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http://earthquake.usgs.gov/image_glossary/
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Earth’s 14 lithosheric plates and their movements
History of the earth
Convergence plate boundary: subduction zone etc.
Divergence plate boundary: Plates diverges at mid-ocean ridges
Transform fault: Plates move laterally each other
theory of continental drift
Before the advent of plate tectonics,
some people already believed that
the present-day continents were the
fragmented pieces of preexisting
larger landmasses. The diagrams
below show the break-up of the
supercontinent Pangaea (meaning
"all lands" in Greek).
http://pubs.usgs.gov/publications/text/historical.html
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Crustal movements
and plate boundaries
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Three types of plate convergence
An oceanic spreading ridge is the fracture
zone along the ocean bottom where molten
mantle material comes to the surface, thus
creating new crust. This fracture can be seen
beneath the ocean as a line of ridges that
form as molten rock reaches the ocean
bottom and solidifies.
An oceanic trench is a linear depression of
the sea floor caused by the subduction of
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one plate under another.
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Four basic types of faults
Strike-slip
Fault: A fault is a fracture along
which the blocks of crust on either side
have moved relative to one another
parallel to the fracture.
Strike-slip faults are vertical (or nearly vertical) fractures
where the blocks have mostly moved horizontally. If the
block opposite an observer looking across the fault moves
to the right, the slip style is termed right lateral; if the
block moves to the left, the motion is termed left lateral.
Normal
Dip-slip faults are inclined fractures where the blocks
have mostly shifted vertically. If the rock mass above an
inclined fault moves down, the fault is termed normal,
whereas if the rock above the fault moves up, the fault is
termed reverse (or thrust). Oblique-slip faults have
significant components of both slip styles.
Thrust
Oblique-slip faults: Oblique-slip faulting suggests
both dip-slip faulting and strike-slip faulting. It is
caused by a combination of shearing and tension or
compressional forces, e.g., left-lateral normal fault.
Dip Slip (normal or thrust)
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Strike Slip (right or left lateral)
Oblique-slip
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Pacific-North American Plate Boundary
Mw=7.5
The San Andreas Fault
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1891
San Andreas
fault
Neodani Fault, Japan
A large intra-plate active fault, caused
the 1891 Nobi EQ (M=8.0)
Dv= 6m
Dh= 4m
1906 San Francisco EQ
M7.7-7.9
Rupture L =470 km
1996
1989 Loma Prieta EQ
M7.0
Rupture L = 40 km 37
http://research.kahaku.go.jp/rikou/namazu/04nobi/noubi.html
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Focal Mechanism
Dip: Dip is the angle that a planar
geologic surface (for example, a fault) is
inclined from the horizontal.
Fault plane solution: A fault
plane solution is a way of showing
the fault and the direction of slip
on it from an earthquake, using
circles with two intersecting
curves that look like beach balls.
Also called a focal-mechanism
solution.
Strike: The strike is the trend or bearing,
relative to north, of the line defined by the
intersection of a planar geologic surface (for
example, a fault or a bed) and a horizontal
surface such as the ground.
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T: Tension axis
P: Pressure axis
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http://quake.wr.usgs.gov/recenteqs/beachball.htm
Slip: Slip is the relative
Surface faulting: Surface faulting
displacement of formerly
adjacent points on opposite
sides of a fault, measured
on the fault surface.
is displacement that reaches the
earth's surface during slip along a
fault. Commonly occurs with shallow
earthquakes, those with an epicenter
less than 20 km. Surface faulting also
may accompany aseismic creep or
natural or man-induced subsidence.
Asperity: An asperity is an area on a fault that
is stuck. The earthquake rupture usually begins at
an asperity.
The 1990 Luzon EQ
Blind thrust fault: A blind thrust fault
is a thrust fault that does not rupture all the
way up to the surface so there is no
evidence of it on the ground. It is "buried"
under the uppermost layers of rock in the
crust. (e.g. the 1994 Northridge EQ)
Directivity: Directivity is an effect of a fault
rupturing whereby earthquake ground motion in
the direction of rupture propagation is more
severe than that in other directions from the
earthquake source.
Shake Map of the 1994 Northridge earthquake shows the
result of rupture directivity toward the north.
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Source Regions of the Destructive Earthquakes in
Japan (1885-1999, Depths of 100 km or less)
Active Fault: An active
fault is a fault that is likely to
have another earthquake
sometime in the future.
Faults are commonly
considered to be active if they
have moved one or more
times in the last 10,000 years.
Inter-plate EQs and
Intra-plate EQs
Historic: Refers to the period for which historical
records are available (approximately the past 200 years
in California and Nevada).
Holocene: Refers to a period of time between the
present and 10,000 years before present. Faults of this
age are commonly considered active.
http://quake.wr.usgs.gov/info/faultmaps/
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Distribution of Active Faults in Japan
More than 1,500
Active Faults for the
Fundamental Survey
Active Fault Surveys
„ Topographical survey
(field survey, air photos)
„ Trenching
1995-2005
98 fault zones
„ Underground structure survey
(seismic reflection)
A class: Average slip of 1-10 m per 1,000 years
B class: Average slip of 10-100cm per 1,000 years
C class: Average slip of 1-10cm per 1,000 years
Number of active faults in Japan
A class: 100, B class=750, C class=450
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Satellite SAR Image and Faults
Valley
Fault
Cabalete Is.
Mauban
Philippine
Fault Zone
Alabat Is.
Manila
Trench
Atimonan
Unisan
Gumaca
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Active Faults in Metro Manila
Lopez
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