observations geotechnical and structural gsmt, new york city...

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2016 Mw7.8 Ecuador Earthquake: Relevance to NYC & US Critical InfrastructureEERI-NYNE and ASCE Met Section Infrastructure Group Mini-Symposium

Geotechnicaland StructuralObservations

Guillermo Diaz-Fanas, WSP USAVirginia Diaz, GMS LLP

GSMT, New York CityMay 30, 2017Geotechnical and Structural

Observations

Mr. Guillermo Diaz-Fanas, PEWSP USA, New York, NY

Ms. Virginia Diaz, PEGMS LLP, New York, NY

2016 Mw7.8 Ecuador EarthquakeNew York City, 5/30/17




GSMT, New York CityMay 30, 2017

OUTLINE

GEER-ATC TEAMSubtopic · Subtopic · Subtopic

Subtopic · Subtopic

GEOTECHNICAL OBSERVATIONSSubtopic · Subtopic

STRUCTURAL OBSERVATIONSSubtopic · Subtopic

Subtopic · Subtopic · Subtopic

CONCLUSIONS





GEER-ATC TEAM

R. GilsanzGMS

(ATC)

D. AlzamoraFHWA

V. DiazGMS/ATC

A. ZekkosU. Michigan

C. WoodU. Arkansas

G. LyversArmy Corps

K. RollinsBring. Young U.

G. Diaz-FanasWSP USA

R. LuqueUC Berkeley

E. MirandaStanfordPEER

E. MoralesU. Buffalo

Ecuadorian Army

S. NikolaouWSP USA

Leader (US)

X. VeraUCSG

Leader (EC)

Ecuadorian

Ministry of Housing

Ecuadorian and Colombian Collaborators:EC Government EC Army, Geodynamics Institute, T.Toulkeridis, C. Arteta, A. Alvarado, A. Caicedo, C. Luque, W. Mera, G.Ponce, F. Ripalda, L. Rodriguez, C. Salcedo, G. Vela, J. Vera-Grunauer,F. Yepes

US Collaborators:T. Kishida, T. O’Rourke, B. Casares, N. Antonaki, P. Kokkali, J.O’Connor, A. Stavridis, P. Lopez, S. Maalouf, L. Hernandez, E.Vaxevanis, J. Mezher, P.Bassal





1.4g

1.06g

0.37g

0.52g

0.38g

0.02g

0.19g

0.09g

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yGROUND FAILURE

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2016 Mw7.8 Ecuador Earthquake Mini-Symposium and Panel Discussion, NYC, 5/30/17

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Yi-H

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yMANTA PORT

Yard 500





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K, Rollins (2016)

MANTA PORT

Extensive sand boils. Lateral/verticalmovement/cracks at south parking lot/

Post-liquefaction settlement





MANTA PORT





EMBANKMENTSBridge

30 to 60 cm of settlementrelative to bridge Sliding and rotating

block away fromembankment

Displacement5 cm to 2 m

Crest of slopeplunging

Failure planes

Rotation of Sign Lateral displacementof toe of slope

CircularFailureplanes

RIO CHICO BRIDGE EMBANKMENT

MEJIA BRIDGEMEJIA BRIDGE

RIO CHICO BRIDGE EMBANKMENT

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MEJIAEMBANKMENT

– BRIDGE

Adrian Tola, Virginia Tech University





Ground uplift, rotation,cracks at top of slope.

Road rotation, settlement.Slope cracks, bulging.

Soil lateralmovement at top.

Earth lifting at base.

LANDSLIDES - DRONESLANDSLIDES





STEP #:1INITIAL CONDITIONS





STEP #:2DRONE IMAGING

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STEP #:3CONSTRUCTION 3D MODEL





DRONE IMAGES TAKEN BY A DRONE

DRONE IMAGES UPLOADED AND PROCESSED INTO SOFTWARE

3D SURFACE, 3D MODEL AND POINT CLOUD FILES ARE PRODUCED

DATA READY TO BE OVERPLAYED AND ANALYZED











STEP #:4OVERLAYING BEFORE AND AFTER

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STEP #:5DATA PROCESSING & APPLICATIONS

DATA READY TO BE OVERPLAYEDAND ANALYZED

DATA COLLECTED AFTER THE EVENTDATA BEFORE THE EVENT

3D CAD SOFTWARE

VOLUMETRIC RESULTS





3D VISUALIZATIONWSP USA TECHNICAL EXCELLENCE CENTER

LANDSLIDESUSE OF TECHNOLOGY





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0.52g

0.38g

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SITE RESPONSEEFFECTS





Vs30 = 1070 m/sSite Type B+

(Hard ROCK)Station AGYE

15x

larg

er

Vs30 = 101 m/sSite Type F

(DEEP SOFT SOILS)Station AGYE2

R = 290 km, Guayaquil

Vs (m/s)

Dept

h(m

)

Te ~ 1.5 s

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COMPARISON TONEC-15 DESIGN SPECTRA





PORTOVIEJO CITY

BEFORE EQ AFTER EQ





Vs30 =247m/sVs30 =210m/s

a < 0.5 (NEC-15Site F

PORTOVIEJO CITY





Sa/PGA ≈ 5

PORTOVIEJO CITY

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SUMMARYGEOTECHNICAL OBSERVATIONS

• Site conditions are generally Class “F”

– Deep, soft, plastic clay deposits, or– Liquefiable man-made fills

– Site effects were evident

– Large soil amplification (> 10 times the rock motions)– Extensive liquefaction– Landslides and slope instabilities– Infrastructure – bridge embankments, dams

ü Geomorphology/Geology Matters!!




GSMT, New York CityMay 30, 2017AFFECTED AREAS - RECONNAISSANCE

The Manabi Province suffered the most damage.Pedernales (one of the closest to the epicenter), Bahia de Caraquez, Manta, and Portoviejowere the most affected among other cities within the Manabi Province.

Ref: Google Earth and USGS Shake Map of Muisne, Ecuador M7.8





STRUCTURAL OBSERVATIONS• Building Inventory and Construction Types• Construction Means/Methods/Implementation• Building Codes and Evolution• Damage Assessment/Tagging/Incorporation of ATC-20• Main Structural Observations and Structural Behavior• Non-structural Components• Residential and Commercial Buildings• Essential/Critical Buildings• Special Structures, Tanks, Camaroneras• Case Studies

– Bridges– Ports– Hospitals, Schools/Critical Facilities– Dams– Seismically Isolated Structures– Cementeries www.geerassociation.org




GSMT, New York CityMay 30, 2017Building Inventory and Construction Types

Building types in the earthquake-affected areas:

•Reinforced Concrete (RC) Buildings: these can be subdivided into three categoriesbased on the construction type:

·Reinforced concrete buildings with a modified two-way joist waffle slabs system, supportedon reinforced concrete columns. Typically, the form blocks in the waffle slabs are not removedafter slab placement.·Reinforced concrete buildings with one-way beams and waffle slabs, supported on reinforcedconcrete columns.·Reinforced concrete buildings with moment resisting concrete frames and two-way waffle orflat slabs, supported on reinforced concrete columns

•Steel Framed Buildings•Wood Framed Buildings: these were typically two-story buildings and single-storyresidences with metal roof decks.

In general, all these structures had masonry infill, hollow brick masonry partitions andunreinforced hollow clay masonry.

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Photo by GMSLLP –GEER-ATC. (GPS coordinates: 0°57’29.9”S, 80°42’42.1”W)

Plastic hinging in the first floor columns ofthis residential building with first floorcommercial occupancy in Tarqui, Manta.

Construction : Reinforced Concrete (RC) Buildings with a Modified Two-Way JoistWaffle Slabs System, Supported on Reinforced Concrete Columns

Building Inventory and Construction Types





Photos by GMSLLP & Droneando © (GPS coordinates: 0°57'28.67"S, 80°42'32.41"W)

Construction : Residential building under construction with two-way waffleslabs in Tarqui, Manta Typically, the form blocks in the waffle

slabs are not removed after slab placement.




GSMT, New York CityMay 30, 2017Reinforce concrete detailing

There is a lack of seismic detailing as well as typical gravity detailing in existing and newconstruction. This was observed in the majority of the buildings. Common findingsincluded:

• Dowels missing in slab and column connections.

• Stirrups that were made with smooth steel with an approximate diameter of 1/4

in. (6.4 mm) in most cases.

• Stirrup spacing that seemed to be as large as the effective element depth for

beams and columns.

• Large stirrup spacing in two-way slabs.

• Stirrups spacing that did not decrease towards the ends of columns.

• Columns that were not confined.

• Smooth longitudinal steel in the columns of some older buildings.





Photo by GMSLLP & C. Arteta Torrents. (GPS coordinates: 0°27'42.67"S, 80°27'20.67"W)

Failure of first floor columns in a buildingunder construction in Canoa. The columnhas large stirrup spacing.The slab to column connection at theedge shows a lack of dowels andtherefore provides no structural integrity

Reinforce concrete detailing

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Photo by C. Arteta Torrents. (GPS coordinates: 0°57'14.55"S, 80°42'53”W)

Damage at the base of six-story mixed-occupancy building in Tarqui, Manta. There issignificant spalling at the bottom of the firstfloor columns, exposing smooth longitudinalrebar and hoop spacing of approximately 2/3of the column width.

Reinforce concrete detailing




GSMT, New York CityMay 30, 2017Main Structural Observations and Structural Behavior

•Soft story damage

•Captive columns

•Rebar corrosion

•Pounding

•Failure of nonstructural walls

•Stairs

•Building Collapse





Photo by GMSLLP –GEER-ATC. (GPS coordinates: 0°57’29.9”S, 80°42’42.1”W)

Soft Story

The first floor of this building in Tarqui, Mantacollapsed. Some of the rebar in the columnsthat failed were corroded. Additionally,Column confinement was not apparent .

Main Structural Observations and Structural Behavior





Photos by GMSLLP –GEER-ATC. (GPS coordinates: 0°4’16.9"N, 80°3'20.0"W)

Soft Story

Soft story failure on second floor in residential building in Pedernales


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Photos by GMSLLP –GEER-ATC. (GPS coordinates: 1°3'13.53"S, 80°27'8.60“W )

Captive Columns / short columns

The fourth and fifth floors collapsedin this office building in PortoviejoThe concrete blocks restrained thecolumn height, causing captivecolumn failure for this column.






Photos by GMSLLP –GEER-ATC. (GPS coordinates: 0°4‘10.31"N, 80°3'28.7"W)

Captive Columns / short columns

First floor columns failure in this residential building inPedernalesThe concrete blocks restrained the column height,causing captive column failure.






Photos by GMSLLP & C. Arteta Torrents.

Tarqui, MantaRebar Corrosion

Rebar corrosion in a beam-columnconnection, and slab reinforcement in athree-story building located in Tarqui, Manta(GPS coordinates: 0°57'7.94"S,80°42'41.90"W).

Rebar area reduction at the base of acolumn and failure in a two-story houselocated in Tarqui, Manta (GPS coordinates:0°57'19.77"S, 80°42'40.68"W).






Photos by GMSLLP & C. Arteta Torrents. (GPS coordinates: 0°57'6.08"S, 80°42'48.85"W )

Pounding

Pounding evidence in Hotel Las Gaviotas in Tarqui, Manta


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Pounding of two buildings in Portoviejo. Photos by GMSLLP (GPScoordinates: 1°3’11.6”S, 80°27’8)

Bahia Airport - Photo by GMSLLP (GPS coordinates:0°36’5.3”S, 80°24’27.0”W)

PoundingMain Structural Observations and Structural Behavior





Photos by GMSLLP –GEER-ATC.

Failure of nonstructural wallsConcrete building with wood and metal deck extension inPortoviejo. Nonstructural wall completely collapsed (GPScoordinates: 0°57’14.6”S, 80°42’38.5”W).

Concrete building in Canoa where brick andmasonry exterior walls collapsed. (GPScoordinates: 0°27'46.59"S, 80°27'23.56"W)






Photos by GMSLLP –GEER-ATC. (GPS coordinates: 0°4’6.2"N, 80°3‘32.7"W )

Stairs

Residentialbuilding inPedernales,where theexterior wallscollapsed.Stair failure isalso observed.






•Construction Materials

•Alterations – Addition of floors

•Dowels

Construction Means/Methods/Implementation

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Building materials near Los EsterosMarket in Tarqui, Manta.

• Fine aggregate with sea shells.• Good quality coarse aggregate

Photos by GMSLLP & C. Arteta Torrents. (GPS coordinates: 0°57'8.94"S, 80°42'29.38"W)

Construction MaterialsConstruction Means/Methods/Implementation





Alterations /Addition of floorsConstruction Means/Methods/Implementation










Alterations /Addition of floors – Common PracticeConstruction Means/Methods/Implementation

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Photos by GMSLLPUnidad Educativa “Linus Pauling” (GPS coordinates: 0°57’23.3”S, 80°42’41.0”W).






STRUCTURAL OBSERVATIONS – CONCLUSIONS

• The majority of buildings observed were reinforced concrete buildings with amodified two-way joist waffle slabs system supported on reinforced concretecolumns. No use of shear walls or RC moment frames (redundancy)

• There was a lack of earthquake resistant details and structural integrity.

• The use of sand and sea water as materials in the concrete is a commonpractice.

• Buildings were regularly observed to have additional floors on top when morespace was required.





www.geerassociation.org

STRUCTURAL OBSERVATIONS• Building Inventory and Construction Types• Construction Means/Methods/Implementation• Building Codes and Evolution• Damage Assessment/Tagging/Incorporation of ATC-20• Main Structural Observations and Structural Behavior• Non-structural Components• Residential and Commercial Buildings• Essential/Critical Buildings• Special Structures, Tanks, Camaroneras• Case Studies

– Bridges– Ports– Hospitals, Schools/Critical Facilities– Dams– Seismically Isolated Structures– Cementeries




GSMT, New York CityMay 30, 2017GEOTECHNICAL AND STRUCTURAL

OBSERVATIONS

Thank you!

2016 Mw7.8 Ecuador EarthquakeNew York City, 5/30/17

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observations geotechnical and structural gsmt, new york city...

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