Ralph Rollins, performed geotechnical investigations for over 5000 structures. I took Soil Mechanics class from my Father

Transcription

1 Ralph Rollins, performed geotechnical investigations for over 5000 structures I took Soil Mechanics class from my Father

2 Rachel Rollins is a Civil Engineering student Rachel took Soil Mechanics class from her Father

3 Granddaughter, Ella, shows early interest in soil behavior

4 Post-Earthquake Geotechnical Reconnaissance Studies Kyle Rollins Civil & Environmental Engineering Brigham Young University

5 EERI Learning From Earthquakes

6 GEER Team Members in Chile

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8 Travel in Japan after Fukushima failure Carried Geiger counter Radiation less than would be received if we stayed in US

9 Earthquake Interrupts Earthquake Briefing

10 Process of Investigation Coordinate/Collaborate with local engineers/researchers 1 st wave: Initial overview of areas of interest by advance team 2 nd wave: Follow-up with second wave to provide more detailed examination of key sites 3 rd wave: Measurement of soil properties in key areas [V s, SPT (N 1) 60, CPT q c, I c, etc.]

11 Understand the Seismo-Tectonic Setting Magnitude Fault type (Strike-slip, Normal, thrust, Subduction) Distribution of acceleration stations and measured peak accelerations

12 Tectonic Setting Nazca Plate moving under South America Plate 13 Earthquakes >7.0 since 1973 M9.5 in 1960 largest on record

13 M = 8.8 Chile Earthquake Hospital in Curico R. Boroschek, Universidad de Chile Large Magnitude Subduction Zone Event Long Duration of Shaking (often > 60 s) Well-Designed Earth Systems Shaken Many Opportunities to Gain Knowledge

14 Ground motions K-NET: surface (693) Kik-NET: v array (496) BRI: buildings (50) 16 recordings PGA > 1.0 g R rup = 49 to 500 km

15 Accelerations at K-Net Tsukidate (MYG004 station) (from National Research Institute for Earth Science and Disaster Prevention, NIED, 2011) ~ 50 seconds

16 M7.6 Samara Zone of Amplification ic ion Costa Rica Peninsula Nicoya Peninsula Earthquake 2012 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).

17 Understand the Geologic Setting Areas of deep soft soil Areas of saturated loose sand/fill material Areas of rock or stiff soils Basin structure

18 Understand Surface Geology Relative to Shaking Limon M Samara Epicenter M Limon Epicenter Fig Geology map of Costa Rica (modified from Dutch 2012) with locations of epicenters from M Limon Earthquake and M Samara Earthquake Intensity Map Geology Map

19 What are we looking for?

20 What are we looking for? Liquefaction Triggering Gravels Silts/Sandy Silts/Clayey sands Magnitude effects on liquefaction Liquefaction Effects Settlement Uplift of utilities Lateral Spreading Residual Strength of liquefied soil Pile downdrag

21 What are we looking for? Ground Response and Amplification Topographic Amplification Influence of local soil conditions Basin effects Resonance with structural period Comparison of good and bad performance at adjacent sites Influence of ground improvement on performance

22 What are we looking for? Landslides Slope, acceleration level, duration, etc. Influence of foundation type on performance (shallow vs deep foundations) Performance of utilities/pipelines Performance of levees and dams Behavior of earth retaining systems Performance relative to Tsunami

23 Mechanics of Liquefaction

24 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 soil u = the water pressure tan = the friction coefficient

25 Where will we find liquefaction? Port facilities Beaches Rivers/bridges Low lying areas with loose fill

26 Look for sand boils and ejecta indicating liquefaction Photo credit: D. Zekkos, 2014 Cephalonia

27 Gravel Ejecta after 2008 M7.6 Wenchuan, China Earthquake Photo Credit: Cao et al, 2013

28 Chinese Dynamic Cone Penetrometer

29 Gravel Liquefaction Curves

30 Liquefiable soil

31 Liquefaction in Adapazari, Turkey Photo credit: USGS Sanchio et al (2004)

32 Effects on buildings (e.g., Kamisu City) GEER 2011 (photo: Boulanger)

33 GEER 2011 (photo: K.M. Rollins)

34 GEER 2011 (photo: Rollins)

35 Settlement analyses for the Urayasu area Katsumata K &Tokimatsu (2012) 2) AIJ procedures Missing information? Other procedures? Bias & dispersion?

36 Liquefaction around Pile Supported Ferris Wheel GEER Photo: K.M. Rollins

37 Building Settlement & Rotation Constructed on 26 m long concrete Piles (3 Rotation) GEER 2011 (photo: K.M. Rollins)

38 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.

39 Shear wave velocity, V s, from Surface Wave Measurements at Liquefaction Site-Costa Rica 2012 Vs profile: R. Luna

40 Drag Load & Settlement from Liquefaction Applied Load Negative Side Shear Reduced Side Shear Non-Liquefiable Soil Liquefiable Liquefied Soil Bearing Stratum End-Bearing

41 Juan Pablo II Bridge, Concépcion Bent damage due to lateral spreading on NE approach Liquefaction-induced pier settlements along bridge span Photo taken from NE Lateral spreading N Pier settlement

42 Juan Pablo II Bridge Liquefaction-induced pier settlements along bridge span Piers # Piers # m-0.7m Modes of deformation Liquefaction-induced pier settlement

43 Before earthquake After earthquake

44 Port of Coronel, South of Concepcion

45 Lateral Spreading at Puerto Coronel

46 T. Leslie Youd Emeritus Prof. BYU Bring a tape and a field book, not just a camera!

47 Lateral Spreading at Puerto Coronel 1.40 Coronel, Chile Port Lateral Spread Cumulative Horizontal Displacement (m) Line 1 Line Distance from Wall Face (m)

48 Lateral Spreading Damage - Ports Ground Movement 2010 M8.8 Maule Chile Earthquake

49 Sketch from field notes

50 Base Isolated Pier (< 0.5 m offset) Base isolators Stabilizing Pile

51 Collapse Holes from Lateral Spreading

52 Collapse Holes from Lateral Spreading

53 Lateral Spreading at Puerto Coronel

54 Lateral Spreading at Puerto Coronel Near Port Coronel, Chile Lateral Spread 3 Cumulative Horizontal Displacement (m) Distance from Wall Face (m)

55 Fisherman s Pier at Coronel Damaged piles due to lateral spreading Lateral spread measurement line

56 Lateral Spreading near Puerto Coronel Ground Movement

57 D=2.8 m (N 1) 60 < 10 D=1.5 m 0<(N 1 ) 60 < 15 D=0.45 m 16<(N 1 ) 60 D= 0 m 20<(N 1 ) 60

58 Contrasting Performance of Adjacent Piers

59 Contrasting Performance of Adjacent Structures

60 Contrasting Performance of Adjacent Structures

61 Geo-referenced Photographs

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64 Port of Iquique, Chile April 2014

65 Cone Penetrometer Testing (Donated by ConeTec)

66 Cone Penetration Test Soundings

67 Port of Iquique, Chile April 2014

68 UAVs for Reconnaissance

69 Identifying unique points from multiple directions

70 Structure from Motion Point Clouds Kevin Franke, BYU

71 Structure from Motion Point Clouds

72 Measured vs. UAV Displacements Cumulative Displacement (m) Section Through CPT 3, 4 and 5 UAV-CPT 3,4 and 5 North End of Pier UAV North End of Pier Distance from West Base (m)

73 Passive Force from Lateral Spreading Liquefaction Passive force often drives displacement Selection of smaller passive force (lower K p ) may be unconservative

74 Lateral Spread of Abutment in bridge Shearing of back wall on beam 35 cm offset in rebar

75 Lateral Spreading Around Abutment Retaining wall Abutment wall

76 Lateral Spread Damage-Bridge 1991 Limon, Costa Rica Earthquake

77 Obtain plans for bridge foundations

78 m m m m Rio Estrella Bridge, Costa Rica, 1991

79 Liquefaction in the Atacama Desert?

80 Liquefaction in the Desert?

81 Liquefaction at Tana Bridge

82 Liquefaction in the Atacama Desert

83 Lateral Spreading at Puerto Valparaiso Apparent lateral spreading at Berth 5 Lateral displacement and settlement behind dock wall

84 Lateral Quaywall Movement at Puerto Valparaiso

85 Lateral Spread at Puerto Valparaiso 60 Valpariso, Chile Port Lateral Spread Cumulative Horizontal Displacement (cm) Horizontal Movement Distance from Wall Face (m)

86 Lateral Spreading at Port of Valparaiso

87 Juan Pablo II Bridge Lateral spreading and bridge bent damage on NE approach Deck settlement Lateral spread Deck settlement Liquefaction Deck settlement Lateral spread Shear failure Lateral spread evidence of liquefaction

88 La Mochita Bridge, Concépcion

89 Site Effects: Vespucio Norte & Ciudad Empresiarial A B Q fno no: Silt & Clay Layers B A Silty Clay, Silty Sand Collapse No collapse Gravel, Sandy gravel Localized Damage Site Effects? H/V peaks: 0.5-2sec (Bonnefoy et al, 2008) Damage to 5 to 20-story buildings

90 Liquefaction at Strong Motion Sites GEER 2011 (photo: K.M. Rollins)

91 Strong ground motion stations with liquefaction nearby GEER 2011 (photos: Boulanger)

92 Station CHB009 Station CHB CHB009 - NS GEER 2011 (photos: Boulanger) CHB024 - NS Acceleration ( g) CHB009 - EW CHB024 - EW Time ( s ) Time ( s )

93 Landslides in Steep Slopes/Stiff dry clay West of Arauco

94 Landslides in Steep Slopes/Stiff dry clay

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96 Bearing Failure and Lateral Spread at Tupul Bridge Bearing failure along highway Lateral spreading impacts bridge abutment Tupul Bridge

97 Failure of Highway Embankment Embankment Fill Soft Clay Liquefiable Zone Embankment Fill Soft Clay Liquefiable Zone

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100 Skewed Bridge Abutment Overview 40% of 600,000 bridges in US are skewed Current AASHTO design code does not consider any effect of skew on passive force Observations of poor performance of skewed bridges Shamsabadi et al. 2006

101 Greater Damage to Skew Abutments

102 Permanent Abutment Offset at Skewed Bridge 3 inch Transverse Displacement 4 inch Longitudinal Displacement

103 Earthquake Damage to Skewed Bridges (Paine, Chile) Top Bridge Bottom Bridge Top Bridge Top Bridge Bridge decks have rotated and bridge was demolished Bottom Bridge Bridge deck remained was offset in service and was after eventually the earthquake demolished

104 Damage rate for skewed bridges was twice that of non-skewed bridges (Toro et al 2013)

105 Field Test Setup - Plan View 4ftDia. Drilled Shaft Sheet Pile Wall Section AZ kip Actuators 24 ft 22 ft 11 ft wide x 5.5 ft high Pile Cap inch Dia. Steel Pipe Piles Transverse Wingwalls 2 x 4 ft Reinforced Concrete blocks

106 Field Test Setup Elevation View 4ftDia. Drilled Shaft Sheet Pile Wall Section AZ ft m wide x 5.5 ft high x 15 ft long Pile Cap 6ft 6.4m kip Actuators inch Dia. Steel Pipe Piles

107 No Skew - 0 Test Setup

108 15 Skew Test Setup

109 30 Skew Test Setup

110 Passive Force Reduction Factor vs. Skew Reduction Factor, R skew R skew = 8x R² = 0.98 Lab Tests Numerical Analysis Field Tests (This Study) Proposed Reduction Line Skew Angle, [degrees]

111 Settlement and Sliding of Approach Fills

112 Settlement and Sliding of Approach Fills

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115 Damage to braced retaining system GEER 2011 (photo: K.M. Rollins)

116 No Damage Associated with MSE Walls

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120 Highly Corrosive Soil

121 Sand Compaction Piles (Fudo Tetra)

122 Typical Installation Arrangement Area Replacement ratio (A r ) of 10% for low fines to 20% for higher fines Sand Pile Non-liquefiable Soil Z/2 Treatment Area Liquefiable Soil Treatment zone, Z Z/2 Building Area Non-liquefiable Soil Elevation View Sand column Plan View Gravel column

123 Contrast between Tokyo Disney and Urayasu City Liquefaction Space Mount at Tokyo Disney Courtesy Japan Probe Parking Lot at Tokyo Disney Area around structures in Tokyo Disney treated with compaction Piles-little settlement Courtesy Japan Probe Parking lot at Tokyo Disney not treated and experienced 50 cm of settlement

124 GEER 2011 (photo: K.M. Rollins)

125 Seismic Performance of Dams & Levees Coihueco Zoned Earth Dam Upstream Slope Failure Levee Breach Rapel Concrete Dam (most dams performed well)

126 Seismic Performance of Tailings Dams Las Palmas Tailings Dam Failure Approximate area of failure and flow direction

127 Naruse River left levee at km 11.3 GEER 2011 (photo: L. F. Harder)

128 Levee Damage in the Tohoku Region (MLIT 2011) Type and Number of Levee Damage Sites Reported River System Failure Settlement Slope Slumping Levee Cracking Revetment/ Wall Damage Gate Damage Other Total Mabuchi Kitakami Naruse Natori Abukuma TOTAL

129 Tsunami Damage GEER Photo: K.M. Rollins

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133 Car on top of 4 story building

134 Pile Supported Building vs Tsunami

135 Rematch

136 Tips for Sucessful Geotechical Recon Be safe out there Develop friendships during your career Collaborate with local engineers, geologists, seismologists Make use of Google Earth for scouting/reporting Document performance, don t just photograph Use UAVs for topographic mapping Quantify site conditions if possible (Vs, CPT, SPT, DMT) Look for contrasting sites (good/bad performance) Obtain plans where if possible Morning plan of attack, Evening reports