Water: The Enemy of Construction Richard A. Coffman, PhD, PE, PLS - PowerPoint PPT Presentation

Water: The Enemy of Construction Richard A. Coffman, PhD, PE, PLS Associate Professor University of Arkansas August 10, 2015 AASHTO SOC Meeting, Little Rock Arkansas

Overview Expansive Soils Compaction Drilled Shaft Foundations

Compaction

Compaction Zero Air Zero Air Zero Air Zero Air Zero Air Zero Air Voids Voids Voids Voids Voids Voids f(G s ) f(G s ) f(G s ) f(G s ) f(G s ) f(G s ) Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d 5 4 1 3 2 105 ± 5 o C 16-24 Hours Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w

Compaction Zero Air Voids f(G s ) Dry Unit Weight, γ d 3 4 2 1 5 Molding Moisture Content, w

Compaction γ d max Zero Air Voids f(G s ) γ d max Dry Unit Weight, γ d Zero Air Voids 95% γ d max f(G s ) Zone of w opt + 2 to 5% Dry Unit Weight, γ d Acceptance w opt - 2 to 5% w opt 95% γ d max Molding Moisture Content, w Zone of w opt + 2 to 5% Acceptance w opt - 2 to 5% g d =120pcf g d =115pcf g d =115pcf w opt w=17.8% w=16.2% w=19.6% Molding Moisture Content, w

Compaction Zero Air Zero Air Zero Air Zero Air Zero Air Zero Air Voids Voids Voids Voids Voids Voids f(G s ) f(G s ) f(G s ) f(G s ) f(G s ) f(G s ) Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d Dry Unit Weight, γ d 5 4 1 3 2 Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w Molding Moisture Content, w

Compaction Dry Unit Weight, γ d 105 ± 5 o C 16-24 Hours 3 4 2 1 5 Molding Moisture Content, w

Compaction k > Regulatory Limit Acceptable Zero Air Modified Zone Based on k ฀ Regulatory Limit Voids Energy Shear Strength f(G s ) (ASTM D1557) Dry Unit Weight, γ d Overall Acceptable Zone Acceptable Zone Based on Hydraulic Conductivity Standard 75 or 50% of Energy Standard Energy (ASTM D698) (ASTM D698) by Reducing Blow Count Molding Moisture Content, w

Expansive Soils

Hundreds 10000 Remotely Sensed SWCC 1000 Matric Suction, y , [kPa] Matric Suction, y , [kPa] Laboratory (RADAR and Obtained SWCC LAST DAB) (CS-229 and 100 TDR) 10 Conceptual Data In-situ Sensing Measured Data 1 Remote Sensing Measured Data Fitted SWCC using van Genuchten (1980) Fitted SWCC using van Genuchten (1980) 0.1 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 Volumetric Water Content, q , [m 3 /m 3 ]

ψ m θ v

ψ m θ v

ψ m θ v Thunder Scientific (2014)

ψ m θ v SWCC Curve Parameters ( α , m, n)

ψ m θ v 0.5 CS-610 TDR Probe Waveform 0.4 0.3 R = -2.660x + 54.084 0.2 Probe Head Unshielded Leads Reflectance Ratio, R 0.1 RG-8 0 Reflection off Probe Tip L a /L=4.05 -0.1 K a =(La/L) 0.5 =16.4 -0.2 -0.3 Campbell Scientific (2014) -0.4 R = -0.156x + 2.973 L a =1.21m -0.5 18 19 20 21 22 23 24 Distance, x, [m]

0-100 kPa ψ m +/- 1 kPa θ v 10-2500 kPa +/- 1 kPa

1E-10 Spectral Regions of Interest Gamma Rays 1E-8 Clay Content 1E-6 Wavelength (mm) 1E-4 Visible and Photographic IR Bands Color Suction 1E-2 Mineral Type Temperature Thermal IR Band 1E+0 K u Microwave Band (VV) Moisture and 1E+2 Volume Change C Microwave Band (VV, HH, HV, VH) 1E+4

Volume Change Moisture and C Microwave Band (VV, HH, HV, VH) Mineral Type Temperature Clay Content Spectral Regions of Interest Suction Color K u Microwave Band (VV) Photographic IR Bands Thermal IR Band Gamma Rays Visible and 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 1E+2 1E+4 Wavelength (mm)                 * i i i i I I I A e A e A A e A e 1 2 1 2 1 2 1 2 1 2

ψ m     0 0 2 2 ( dB ) 10 * log( )( m m )    θ v 0 0 ( 40 , ) ( 40 , ) t t  dry m ( t ) s    0 0 ( 40 , t ) ( 40 , t ) wet dry Volume Change Moisture and C Microwave Band (VV, HH, HV, VH) Mineral Type Temperature Clay Content Spectral Regions of Interest Suction Color        0 0 K u Microwave Band (VV) m m 0 . 042 ( dB dB ) Photographic IR Bands v v . o 0 Thermal IR Band   Gamma Rays 0 i Visible and  m v  8 . 56 1 . 56 i    0 8 . 56 m 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 1E+2 1E+4 0 v . 0 i  Wavelength (mm) 8 . 56 1 . 56 i

        2   q q  q 0 4 2 4 8 k h cos W 2 k sin ψ m qq qq  1 . 5   2 2            1 kl q        2 sin 1 W k       n n   θ v  n 1     ' 1   0   Volume Change Moisture and C Microwave Band (VV, HH, HV, VH) HH     2 Mineral Type Temperature q    q Clay Content ' 2 cos sin Spectral Regions of Interest Suction Color K u Microwave Band (VV)       Photographic IR Bands       q    q ' 2 ' 2 1 sin 1 sin Thermal IR Band     0 Gamma Rays Visible and VV     2  q    q ' ' 2 cos sin 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 1E+2 1E+4 Wavelength (mm)

1857 MW Coal Fired Facility ψ m 100 x 100 Test Section Full Scale Wetlands θ v Treatment Soil Stockpile V Transmit Antenna V Receive Antenna Field Computer GPRI-II

0.5 0.45 ψ m Reflectance 0.4 θ v 0.35 Smectite SWCC Curve Kaolinite Parameters ( α , m, n) 0.3 Illite Volume Change Moisture and C Microwave Band (VV, HH, HV, VH) Mineral Type Temperature Clay Content 0.25 Spectral Regions of Interest Suction Color 2000 2100 2200 2300 2400 Wavelength, l , [nm] K u Microwave Band (VV) Photographic IR Bands Thermal IR Band Gamma Rays Visible and 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 1E+2 1E+4 Wavelength (mm)

Volume Change Moisture and C Microwave Band (VV, HH, HV, VH) Mineral Type Temperature Clay Content Spectral Regions of Interest Suction Color ψ m RH K u Microwave Band (VV) pH 2 0 (g) Photographic IR Bands Thermal IR Band Gamma Rays Visible and θ v ̊ K [H 2 0 (g) ] 1E-10 1E-8 1E-6 1E-4 1E-2 1E+0 1E+2 1E+4 Wavelength (mm) 12500 10000 Wavenumber (cm -1 ) Absorption Coeffeceient,  [m -1 ] 1E+2 1E+1 1E+0 847 nm 1E-1 1E-2 1E-3 H ₂ O ₍ ₎ 823 nm H 2 0 (l) 1E-4 l H ₂ O ₍ ᵥ ₎ H 2 0 (g) 1E-5 0.8 0.85 0.9 0.95 1 Wavelength ( μ m -1 )

Drilled Shaft Foundations

SSATS SSATS TATS TATS Rock Rock Alluvial Alluvial Deltaic Deltaic Deposits Deposits Deposits Deposits MATS MATS

Test Site SSATS US 63 TATS Rock Turrell, AR N Alluvial Deltaic Test Site Deposits Deposits 200 ft . MATS I-55 100 m

Axial Load, R m , [MN] Axial Load, R m , [MN] Axial Load, R m , [MN] 0 3 6 9 12 0 3 6 9 12 0 3 6 9 12 4 4 Upward Movement Upward Movement (Top of the BLC) Upward (Top of the BLC) Movement 2 2 (Top of BLC) Movement, d, [cm] Movement, d , [cm] 0 0 d, d, Downward Movement -2 -2 (Bottom of BLC) -4 -4 -6 -6 Downward Movement Downward Movement (Bottom of the BLC) (Bottom of the BLC) -8 -8 South 1.2m DSF Center 1.8m DSF North 1.2m DSF

Axial Load, R, [MN] Axial Load, R m , [MN] Axial Load, R, [MN] 0 3 6 9 12 0 3 6 9 12 0 3 6 9 12 0 1 Movement, d, [ cm] 2 3 North 1.2m South 1.2m FBDeep MODOT Mean (N) g T N=blow count FBDeep MODOT 30% (N)  =friction angle FBDeep MODOT Silt (N) Center 1.8m 4  SHAFT MODOT Mean ( ) g T  FB-Deep AHTD Mean (N) FBDeep AHTD (N) SHAFT MODOT 30% ( )  FB-Deep MODOT Mean (N) FBDeep MODOT (N) SHAFT MODOT Silt ( )  FB-Deep UofA Mean (N) FBDeep UofA (N) SHAFT MODOT Combined ( ) SHAFT UofA Mean (N) SHAFT AHTD (N) SHAFT AHTD Mean (N)  g T 5 SHAFT UofA 30% (N) SHAFT MODOT (N) SHAFT MODOT Mean ( ) SHAFT UofA Silt (N) SHAFT UofA Mean (N) SHAFT UofA (N) SHAFT UofA Combined (N) Measured Load-Movement Measured Measured Load-Movement Required Capacity Required Strength Required Capacity 6 South 1.2m DSF Center 1.8m DSF North 1.2m DSF 29

Collapsed Excavation Modified Predictive Model Ground Surface Initial Temporary Casing CLAY SG 10 2.4m 7.0m CLAY Idealized SG 9 4.9m Collapsed 6.1m Volume = SG 8 7.3m 19.93m 3 SILT SILT 9.1m Estimated SG 7 9.8m Final MODELED AS ADDITIONAL SILT (METHOD 3) Collapsed Temporary 12.1m Volume = SG 6 12.2m Casing 3.82m 3 14.0m SG 5 14.0m SAND Approximate SG 4 16.5m Soil Level After MODELED AS Rebar Cage SAND (METHOD 1) Excavation BLC 18.9m OR Placed into Collapse SILT (METHOD 2) SG 3 19.4m the Excavation 15.2m Below SG 2 20.4m Ground Surface SG 1 22.9m

Conclusion Expansive Soils Compaction Drilled Shaft Foundations

Compaction Perform Additional Laboratory Tests Develop Zone of Acceptance (based on k, c u ) Perform Field Verification Rework/Reject Locations Outside of Zone