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Ralph Rollins, performed geotechnical investigations for over 5000 structures
I took Soil Mechanics class from my Father
Rachel Rollins is a Civil Engineering student
Rachel took Soil Mechanics class from her Father
Granddaughter, Ella, shows early interest in soil behavior…
Post-Earthquake Geotechnical Reconnaissance Studies
Kyle RollinsCivil & Environmental Engineering
Brigham Young University
EERI Learning From Earthquakes
GEER Team Members in Chile
Travel in Japan after Fukushima failureCarried Geiger counterRadiation less than would be received if we stayed in US
Earthquake Interrupts Earthquake Briefing
Process of InvestigationCoordinate/Collaborate with local engineers/researchers1ststst wave: Initial overview of areas of interest by advance team2ndndnd wave: Follow-up with second wave to provide more detailed examination of key sites3rdrdrd wave: Measurement of soil properties in key areas [Vss, SPT (N11)1 60606 , CPT qcc,c Icc, etc.]
Understand the Seismo-Tectonic Setting
MagnitudeFault type (Strike-slip, Normal, thrust, Subduction)Distribution of acceleration stations and measured peak accelerations
Tectonic Setting
Nazca Plate moving under South America Plate13 Earthquakes >7.0 since 1973M9.5 in 1960 largest on record
M = 8.8 Chile Earthquake
Large Magnitude Subduction Zone Event
Long Duration of Shaking (often > 60 s)
Well-Designed Earth Systems Shaken
Many Opportunities to Gain Knowledge
Hospital in Curico R. Boroschek, Universidad de Chile
Ground motionsK-NET: surface (693)Kik-NET: v array (496)BRI: buildings (50) 16 recordings PGA > 1.0 gRrup = 49 to 500 km
Accelerations at K-Net Tsukidate (MYG004 station)(from National Research Institute for Earth Science and Disaster Prevention, NIED, 2011)
~ 50 seconds
M7.6 Samara Costa Rica Earthquake2012
Nicoya Peninsula
Zone of Amplification
Fig. 1.1 – Location of epicenter and peak ground accelerations measured by the seismic network operated by the Engineering Seismology Laboratory (LIS) at the University of Costa Rica. The recordings are color coded according to the acceleration level and Mercalli scale categories shown at the base of the map (LIS, 2012a).
NiNNicocooyayaaayaaaa Peniinnsullaa
ZoZoZoZoooZoooneneneneneneenennnenennnnennnen ooooooooff ff ff AmAmAmAmAmmAmAmAmmAmAmmmmAmmmmmmmAmmmmmAmmmmmmmAmmmmmmmmmmmmmAmmmmmmmmmmmmAmmAmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmpppplpplplppplplplpplplpplppplpppppppppppppppppppppplplplpppppppppppppppp ififffififffifii icicicciciciicici atattataatatatatataaataaataaaaaaaatataaaataaaaatioioiioioioionnnnn
Peninsula
Understand the Geologic Setting
Areas of deep soft soilAreas of saturated loose sand/fill materialAreas of rock or stiff soilsBasin structure
Fig. 2.1 - Geology map of Costa Rica (modified from Dutch 2012) with locations of epicenters from M7.5 1991 Limon Earthquake and M7.6 2012 Samara Earthquake
M7.5 1991 Limon Epicenter
M7.5 2012 SamaraEpicenter
Limon
Intensity Map Geology Map
Understand Surface Geology Relative to Shaking
What are we looking for?
What are we looking for?Liquefaction Triggering
GravelsSilts/Sandy Silts/Clayey sandsMagnitude effects on liquefaction
Liquefaction EffectsSettlementUplift of utilitiesLateral SpreadingResidual Strength of liquefied soilPile downdrag
What are we looking for?Ground Response and Amplification
Topographic Amplification Influence of local soil conditionsBasin effectsResonance with structural period
Comparison of good and bad performance at adjacent sitesInfluence of ground improvement on performance
What are we looking for?Landslides
Slope, acceleration level, duration, etc.Influence of foundation type on performance (shallow vs deep foundations)Performance of utilities/pipelinesPerformance of levees and damsBehavior of earth retaining systems Performance relative to Tsunami
Mechanics of Liquefaction
Definition of Liquefaction
A decrease in strength and stiffness caused by a build-up of water pressure due to earthquake
shaking.
= ( - u) tan
where = vertical stress from soilu = the water pressure
tan = the friction coefficient
Where will we find liquefaction?
Port facilitiesBeachesRivers/bridgesLow lying areas with loose fill
Look for sand boils and ejecta indicating liquefaction
Photo credit: D. D. Zekkosos, 2014 Cephalonia
Gravel Ejecta after 2008 M7.6 Wenchuan, China Earthquake
Photo Credit: Cao et al, 2013
Chinese Dynamic Cone Penetrometer
Gravel Liquefaction Curves
Liquefiable soil
Liquefaction in Adapazari, Turkey
Photo credit: USGS Sanchio et al (2004)
GEER 2011 (photo: Boulanger)
Effects on buildings (e.g., Kamisu City)
GEER R 2011 1 (photo: K.M. Rollins)
GEER 2011 (photo: Rollins)
Settlement analyses for the Urayasu area
Katsumata &Tokimatsu (2012) 2) –– AIJ proceduresKatsumata &Tokimatsu (2012)K 2) AIJ proceduresAMissing information? Other procedures? Bias & dispersion?
Liquefaction around Pile Supported Ferris Wheel
GEER Photo: K.M. Rollins
Building Settlement & Rotation
Constructed on 26 m long concrete Piles (3° Rotation)
GEER 2011 (photo: K.M. Rollins)
Liquefaction settlement of building on shallow footings
Fig. 2.5 – Foundations Punching through liquefied ground (a) exterior column, north side; (b) interior column, left behind a 60cm crater.
Shear wave velocity, Vs, from Surface Wave Measurementsat Liquefaction Site-Costa Rica 2012
Vs profile: R. Luna
Drag Load & Settlement from Liquefaction
Bearing Stratum
Liquefiable Soil
Non-Liquefiable Soil
Endnd-d-Bearing
Side Shear
Applied Load
Reduced SSSSSSSSSSSSSSSSSSSSiiiiiiiiiiiiiiiidddddddddddddddddddddeeeeeeeeeeeeeeeeeeeee SSSSSSSSSSSSSSSSSSSShhhhhhhhhhhhhhhhhhhheeeeeeeeeeeeeeeeeeeeeaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrSSSSSSSSSSSSSSSSSSSSiiiiiiiiiiiiiiiiiidddddddddddddddddddddeeeeeeeeeeeeeeeeeeeee SSSSSSSSSSSSSSSSSSSShhhhhhhhhhhhhhhhhhhhheeeeeeeeeeeeeeeeeeeeaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrReduced Side Shear Liquefied Soil
Negative Negative Side Shear
Lateral spreading
Pier settlement
Juan Pablo II Bridge, ConcépcionBent damage due to lateral spreading on NE approachLiquefaction-induced pier settlements along bridge span
N
Photo taken from NE
Piers # 113-116 Piers # 113-116
Juan Pablo II BridgeLiquefaction-induced pier settlements along bridge span
0.5m-0.7m
Modes of deformationLiquefaction-induced pier settlement
Before earthquake
After earthquake
Port of Coronel, South of Concepcion
Lateral Spreading at Puerto Coronel
“Bring a tape and a field book, not just a camera!”
T. Leslie YoudEmeritus Prof. BYU
Lateral Spreading at Puerto CoronelCoronel, Chile Port Lateral Spread
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
0 5 10 15 20 25 30Distance from Wall Face (m)
Cum
ulat
ive
Hor
izon
tal D
ispl
acem
ent (
m)
Line 1Line 2
Lateral Spreading Damage - Ports
Ground Movement
2010 M8.8 Maule Chile Earthquake
Sketch from field notes
Base Isolated Pier (< 0.5 m offset)
Base isolators Stabilizing
Pile
Collapse Holes from Lateral Spreading
Collapse Holes from Lateral Spreading
Lateral Spreading at Puerto Coronel
Lateral Spreading at Puerto CoronelNear Port Coronel, Chile Lateral Spread
0
0.5
1
1.5
2
2.5
3
0 20 40 60 80 100Distance from Wall Face (m)
Cum
ulat
ive
Hor
izon
tal D
ispl
acem
ent
(m)
Fisherman’s Pier at Coronel
Lateral spread measurement line
Damaged piles dueto lateral spreading
Lateral Spreading near Puerto Coronel
Ground Movement
D=2.8 m
D=1.5 m
D=0.45 m
D= 0 m
(N11)1 60606 < 10
10<(N11)1 60606 < 15
16<(N11)1 60
20<(N11)1 60
Contrasting Performance of Adjacent Piers
Contrasting Performance of Adjacent Structures
Contrasting Performance of Adjacent Structures
Geo-referenced Photographs
Port of Iquique, Chile April 2014
Cone Penetrometer Testing (Donated by ConeTec)
Cone Penetration Test Soundings
Port of Iquique, Chile April 2014
UAVs for Reconnaissance
Identifying unique points from multiple directions
Structure from Motion Point Clouds
Kevin Franke, BYU
Structure from Motion Point Clouds
Measured vs. UAV Displacements
0.0
0.5
1.0
1.5
2.0
2.5
0 10 20 30 40 50 60
Cum
ulat
ive
Disp
lace
men
t (m
)
Distance from West Base (m)
Section Through CPT 3, 4 and 5UAV-CPT 3,4 and 5North End of PierUAV North End of Pier
Passive Force from Lateral Spreading
Passive force often drives displacementSelection of smaller passive force (lower Kpp)may be unconservative
Liquefaction
Lateral Spread of Abutment in bridge
355 cm 355 m cmoffset in offset in
rebar
Shearing of Shearing of back wall back wall on beam
Lateral Spreading Around Abutment
Retaining wall Abutment wall
Lateral Spread Damage-Bridge
1991 Limon, Costa Rica Earthquake
Obtain plans for bridge foundations
24.96 6 m 75.02 m 75.24 m
176.14 m
Rio Estrella Bridge, Costa Rica, 1991
Liquefaction in the Atacama Desert?
Liquefactionin the
Desert?
Liquefaction at Tana Bridge
Liquefaction in the Atacama Desert
Lateral Spreading at Puerto Valparaiso
Lateral displacement and settlement behind dock wall
Apparent lateral spreading at Berth 5
Lateral Quaywall Movement at Puerto Valparaiso
Lateral Spread at Puerto Valparaiso
Valpariso, Chile Port Lateral Spread
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40
Distance from Wall Face (m)
Cum
ulat
ive
Hor
izon
tal
Dis
plac
emen
t (cm
) Horizontal Movement
Lateral Spreading at Port of Valparaiso
Shear failure
Lateral spread
Liquefaction
Lateral spread
Lateral spread
Deck settlement
Deck settlement
Juan Pablo II Bridge
evidence of liquefaction
Lateral spreading and bridge bent damage on NE approach
Deck settlement
La Mochita Bridge, Concépcion
Site Effects: Vespucio Norte & Ciudad Empresiarial
Gravel, Sandy Gravel, Sgravel
Silty Clay, Silty Sand
CollapseCollapsepNo collapse
H/V peaks: 0.5-2sec (Bonnefoy et al, 2008)Damage to 5 to 20-story buildings
QQQfnoono: Silt & Clay Layers
Localized Damage – Site Effects?
AB
CSilty CA
B
Liquefaction at Strong Motion Sites
GEER 2011 (photo: K.M. Rollins)
GEER 2011 (photos: Boulanger)
Strong ground motion stations with liquefaction nearby
Station CHB024Station CHB009
-0.2
-0.1
0
0.1
0.2
Acc
e ler
a tio
n(g
)
40 80 120 160 200Time (s)
-0.2
-0.1
0
0.1
0.2
CHB009 - NS
CHB009 - EW
-0.2
-0.1
0
0.1
0.2
40 80 120 160 200Time (s)
-0.2
-0.1
0
0.1
0.2
CHB024 - NS
CHB024 - EW
GEER 2011 (photos: Boulanger)
Landslides in Steep Slopes/Stiff dry clay
West of Arauco
Landslides in Steep Slopes/Stiff dry clay
Bearing Failure and Lateral Spread at Tupul Bridge
Bearing failure along highway
Lateral spreading impacts bridge abutment
Tupul Bridge
Failure of Highway Embankment
Liquefiable Zone
Embankment Fill
Soft Clay
Liquefiable Zone
Embankment Fill
Soft Clay
Skewed Bridge Abutment Overview40% of 600,000 bridges in US are skewed
Current AASHTO design code does not consider any effect of skew on passive forceObservations of poor performance of skewed bridges
Shamsabadi et al. 2006
Greater Damage to Skew Abutments
Permanent Abutment Offset at Skewed Bridge
4 inch 4 inch Longitudinal Longitudinal Displacement
3 inch 3 inch Transverse Transverse
Displacement
Earthquake Damage to Skewed Bridges(Paine, Chile)
Top Bridge
Bottom Bridge
Top Bridge
Bridge decks have rotated and bridge was demolished
Bottom Bridge
Bridge deck was offset and was eventually demolished
Top Bridge
Bridge remained in service after the earthquake
Damage rate for skewed bridges was twice that of non-skewed bridges (Toro et al 2013)
Field Test Setup - Plan View
12.75 inch Dia. Steel Pipe Piles
11 ft wide x 5.5 ft high Pile Cap
24 ft
22 ft
Transverse Wingwalls2 x 4 ft Reinforced Concrete blocks
4 ft Dia. Drilled ShaftSheet Pile Wall Section AZ-18
2 – 600 kip Actuators
Field Test Setup Elevation View
11 ft m wide x 5.5 ft high x 15 ft long Pile Cap
6 ft6.4m
4 ft Dia. Drilled ShaftSheet Pile Wall Section AZ-18
2 – 600 kip Actuators 12.75 inch Dia. Steel Pipe Piles
No Skew - 0° Test Setup
15° Skew Test Setup
30° Skew Test Setup
Passive Force Reduction Factor vs. Skew
Rskew = 8x10-05 2 - 0.018 + 1R² = 0.98
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 15 30 45 60 75 90
Red
uctio
n Fa
ctor
, Rsk
ew
Skew Angle, [degrees]
Lab TestsNumerical AnalysisField Tests (This Study)Proposed Reduction Line
Settlement and Sliding of Approach Fills
Settlement and Sliding of Approach Fills
Damage to braced retaining system
GEER 2011 (photo: K.M. Rollins)
No Damage Associated with MSE Walls
Highly Corrosive Soil
Sand Compaction Piles (Fudo Tetra)
Typical Installation Arrangement
Elevation View Plan View
Building Area
Treatment Area
Z/2
Non-liquefiable Soil
Non-liquefiable Soil
Liquefiable SoilTreatment zone, Z
Z/2
Sand column
Area Replacement ratio (Ar) of 10% for low fines to 20% for higher fines
Sand
Pile
Gravel column
Contrast between Tokyo Disney and Urayasu City Liquefaction
Courtesy Japan Probe
Courtesy Japan Probe
Area around structures in Tokyo Disney treated with compaction Piles-little settlement
Parking lot at Tokyo Disney not treated and experienced 50 cm of settlement
Parking Lot at Tokyo Disney
Space Mount at Tokyo Disney
GEER 2011 (photo: K.M. Rollins)
Seismic Performance of Dams & LeveesCoihueco Zoned Earth Dam
Upstream Slope Failure
Rapel Concrete Dam
(most dams performed well)
Levee Breach
Seismic Performance of Tailings DamsLas Palmas Tailings Dam Failure
Approximate area of failure and flow direction
Naruse River left levee at km 11.3
GEER 2011 (photo: L. F. Harder)
RiverSystem
Type and Number of Levee Damage Sites Reported
Failure Settlement SlopeSlumping
LeveeCracking
Revetment/Wall
Damage
GateDamage Other Total
Mabuchi 0 1 1 1 5 1 5 13
Kitakami 13 62 47 278 121 67 58 646
Naruse 9 27 25 183 56 26 37 363
Natori 1 2 1 26 2 2 1 35
Abukuma 2 26 16 73 2 10 3 132
TOTAL 25 118 90 561 186 106 104 1190
Levee Damage in the Tohoku Region (MLIT 2011)
GEER Photo: K.M. Rollins
Tsunami Damage
Car on top of 4 story building
Pile Supported Building vs Tsunami
Rematch
Tips for Sucessful Geotechical Recon
Be safe out thereDevelop friendships during your careerCollaborate with local engineers, geologists, seismologistsMake use of Google Earth for scouting/reportingDocument performance, don’t just photographUse UAVs for topographic mappingQuantify site conditions if possible (Vs, CPT, SPT, DMT)Look for contrasting sites (good/bad performance)Obtain plans where if possibleMorning plan of attack, Evening reports