In Situ Erosion Evaluation Probe ( ISEEP )

Research Lead The University of North Carolina at Chapel Hill CHC-R 5th Annual Meeting January 31-February 1, 2013

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In Situ Erosion Evaluation Probe (ISEEP)

PI: Mo. GabrNorth Carolina State University (NCSU) Ph.D. Student: Mohamad Kayser (Graduation 2014) MS Students: Yulian Kebede, Chris Stryffeler, Steven Toebben (Graduation 2014)

Cary Caruso and Austin Key (Graduated) Summer Interns: Yulian Kebede - Jackson State University

Ian McMillan- The Citadel


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Motivation: What is available? Methods to measure scour potential with

depth require sample removal and lab testing or only provide surface measurements

Methods for rapid assessment of scourability are lacking in literature

Project OverviewScope: Enhancing Capabilities for Rapid Assessment of Erosion/Scour Potential In Situ Erosion Evaluation

Probe (ISEEP)Approach: An in situ process to assess critical erosion/scour parameters:o Threshold Stream Powero Erosion Rate per unit stream power


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DHS Mission RelevanceDHS Mission 5, Ensuring Resilience to Disaster: a tool to assist in fulfilling the

DHS mission of infrastructure protection and hazard mitigation

Rapid deployment over a large area to assess incipient erosion of soil profiles supporting protective structures with approaching storm events

Rapid post storm assessment for locating temporary support infrastructures - an important aspects of emergency management

State and Federal government agencies and private consultants can utilize the device data for: i. hazard mitigation, ii. enhanced preparedness, iii. effective emergency response, and iv. rapid recovery:

Frequent measurement of scour potential (i, ii) Identify scour-critical structures for retrofit and action plan (i, iii) Provide data to estimate post storm stability and time-dependent stability of critical

structures (iii, iv)


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MotivationEnhancing Capabilities for Rapid Assessment of Erosion Potential of Critical Structures

Bridges

Dams and Levees

Roads and Coastal Structures

The Guardian, 2009

Introduction

http://www.guardian.co.uk/theguardian


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ISEEP’ Approach

Ettema, R., Constantinescu, G. and Melville, B. (2011.)

Existing Approaches


6Existing Approaches


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Richardson and Davis (2001)43.035.0

w4321 FrKKKKK 2.0

ay

ays

K1 = pier nose shape (0.9 and 1.1) K2 = angle of attack of flow (1.0 and 5.0)K3 = state of bed-sediment motion (1.1 and 1.3)Kw = correction factor

Vicdx is approach velocity required to initiate scour at the pier for grain size Dx, given by:

0.15R 4 V 0.4 K

9050

50

icdcd

icdR VV

VVV

cdxicdx aDx V 0.645 V

053.0

1/3

x6/1 D 6.19 V ycdx

gyV Fr

Existing Approaches


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A Better Approach? Erosion Parameters

Assess Erosion Parameters of Soil:• Critical Shear Stress • Detachment Coefficient

Assess Shear Stress with Time

Compute Scour Magnitude and Rate

Existing Approaches


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Technical Approach: ISEEP ComponentCone TipRod SectionsCoaxial SheathingPumpControllerWater TankGenerator

Vary Velocity-Maintain Flow Rate

Vary Flow Rate-Maintain Velocity


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Field Testing

Irene Breach

Wake County Bridge

NC-12 Temporary Bridge


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Isabel Breach


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Field Testing

0

10

20

30

40

50

60

70

80

90

100

0.010.1110

% P

assin

g

Grain Size (mm)

Pea Island - Organic Contents

Pea Island - Sand

R² = 0.9658

R² = 0.6868

0

2

4

6

8

10

12

10 100 1000 10000Pe

netr

atio

n R

ate (

cm/s)

Stream Power (Watts/m2)

Pea Island Depth = 0-50 cm

Pea Island Depth = 50-200 cm

Pc

GSD of NC-12 Soil Kd’ and Pc


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Field Data Reduction

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5

Est

imat

ed E

rosio

n R

ate

(m/h

r)

Depth of Flow (m)

Velocity = 3 m/sVelocity = 4 m/s

Assuming an average flow depth of 0.5 m, a 4.2 m breach is estimated to occur in approximately 1.5 hours for a 4 m/s flow velocity and in 9 hours for 3 m/s flow velocity

Field Testing and Modeling


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Modeling of Flow around Bridge Piers

• Sand Bed: 24 m long, 20 m wide and 4 m deep• Layers: Two layers soil system• Approach Velocity: 0.45 m/s to 0.9 m/s • Depth of Flow: 1.0 m • Pier Diameter: 1.22 m

1m 3m 24 m 3m

1.5 m

2.5 m


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3-D Scour Profile

Pier Scour


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Reference Equation Comments

Shen et al. (1969) ds = 0.000223 (Vb/υ)0.619 V = flow velocity, υ = kinematic viscosity of water = 1 × 10-6 m2/s

Breusers et al. (1977) ds /b = f(V/Vc)(2tanh(y/b))KsKtheta

f (V/Vc) = 0, V/Vc≤0.5 =(2V/Vc-1), 0.5<V/Vc≤1 = 1, V/Vc>1Vc = Critical velocity, Ks = shape factor, Ktheta = inclination factor

Jain and Fischer (1979)

ds /b = 1.86(y/b)0.5(Fr – Frc)0.25 Fr = Froude number

Richardson and Davis (1995)

ds/b= 2KsKthetaK3K4(y/b)0.35Fr0.43

K3= factor for mode of sediment transport, K4 = factor for armoring by bed material

Bridge Scour: Empirical Equations


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Bridge Scour: Empirical Equations

0

0.3

0.6

0.9

1.2

1.5

1.8

0 200 400 600 800 1000

Scou

r D

epth

/ Pi

er D

iam

eter

Stream Power (Watt/m2)

ISEEP

FLOW-3D

Shen et al. (1969)

Jain and Fischer (1979)

Richardson and Davis (1995)


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Laboratory Experiments &

Field Testing

Yulian A. Kebede


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Lab Testing with Clay-Sand Mixture

Dry unit weight

(kN/m3)

Mean Particle

Diameter, d50 (mm)

Undrained Shear

Strength, Cu (kPa)

Liquid Limit,

LL

Plasticity Index, PI

17.7 0.26 5-8 20 0

Dry weight of mixture: 10% Fines - 90 % sandInitial water content : 18 % - 23 %


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Lab Testing Results

00.5

11.5

22.5

33.5

10 100

Pene

tratio

n rate (cm

/s)

Stream Power (Watts/m2)

Run time = 15sRun time = 30sRun time = 45sRun time = 60s

• kd 0.017 cm/sec per N/m2 (45 sec) 0.015 cm/sec per N/m2 (60 sec)

•Pc 16 Watts/m2

•Vc

0.32 m/s

•tc

1.75 Pa


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• Flow Velocity range of 1.0 m/s to 2.0 m/s (Froude number 0.23 to 0.45)

• Pier Diameter = 1 m • Depth of flow = 2 m

Ansari et al. (2002)dsmc/dsms = 1.51(C*/φ*)0.2


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ERDC Collaboration: Lake Calumet Testing• Located at far south side of

Chicago, IL• Largest body of water in the city• Highly contaminated due to

years of industrial waste and runoff from nearby land fills

• Contains an approximate water depth of 4 ft with a clay layer located about 1cm beneath the water depth


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Plan• Collaboration with ERDC in effort to

compare and contrast results with that of the Erosion Function Apparatus (EFA)– EFA testing lead by Dr. Joseph Gialani

• Scheduled to take place in March/April• ISEEP testing will be performed onsite

and the EFA testing will collect sample and perform testing in a nearby testing facility


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Next Steps

Extend the collaboration work from the lab to the field by performing field tests at sites where scour rates have been established in the past

Validation Modeling of Various Hydraulic Structures resting on soils with fine contents and Storm Conditions

Incorporation of skin friction factor to the data reduction scheme especially at greater penetration depths.

Process the testing approach and the data reduction scheme for acceptance as ASTM standards


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Milestones Modeling of various types of hydraulic structures resting and assessing applicability of ISEEP for assessment of scour magnitude

Viability of the approach in various types of soils, including soil with fine contents

The refinement of the data reduction scheme with incorporation of factors such as the rods’ skin resistance especially at greater penetration depths

Applicability of the results in view of other existing approaches that require soil sampling


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End Users and Translation Activities Federal Emergency Management Agency (FEMA) U.S. Army Corps of Engineers (USACE)State Offices and Agencies of Emergency ManagementState Offices of Dam Safety

Standardization of the testing process and data reduction scheme , and submission to Committee D18.02 on “Sampling and Related Field Testing for Soil Evaluations” for review and commenting.

The system is available now and the plan is to test it in cooperation with ERDC CHL as outlined in the proposal.

Transition of ISEEP to government and private sector via commercialization processes –Discussion on incubator for a private company, North Carolina State University office of Technology Transfer.


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Media Publicity Gizmag, November 2010 “Safer levees and bridges thanks to new erosion and scour detector” ASCE Civil Engineering Magazine, August 2011-Technology Section, Page 40 “Probe Reveals Hidden Potential of Scour,”Conference Proceedings Cary Caruso and M. A. Gabr (2010)“In Situ measurement of the scour potential of non-cohesive sediments (ISEP)”

Geotechnical Special Publication No. 211, American Society of Civil Engineers (ASCE), pp. 115-125. Cary Caruso and M. A. Gabr (2011) “In Situ Assessment of Scour Potential with Depth Using Jetting Approach,”

Geotechnical Special Publication No. 211, (ASCE), pp.1483-1492. M. Kayser and M. A. Gabr (2013). “Scour assessment in cohesive soil using ISEEP.” Accepted, International Conference

on Soil Mechanics and Geotechnical Engineering, Paris, France, 2013. Posters Caruso, C. W., Poster Presentation at DIEM meeting with DHS Under Secretary of S&T , Chapel Hill, NC, Feb 2011. Caruso, C. W, DHS University Summit Student Day, Washington, DC, Mar., 2011. Kayser, M. and Gabr, M. “Scour Assessment of Bridge Foundations Using an In Situ Erosion Evaluation Probe

(ISEEP)” 92nd Transportation Research Board meeting, Washington DC, January 2013. Journal Papers Gabr, M. A., Caruso, C. W., Key, A., and Kayser, M. “Assessment of In Situ Scour Profile in Sand using a Jet Probe,”,

Journal paper accepted by ASTM, Geotechnical Testing, in press. Kayser, M. and Gabr, M. A. “Scour Assessment of Bridge Foundation Using In Situ Erosion Evaluation Probe (ISEEP).”

Journal paper accepted by the Journal of the Transportation Research Board, in press.Masters Thesis and Masters Project Cary Caruso “In Situ Measurement of the Scour Potential of non-cohesive Sediments “ MS thesis, August , 2011 Austin Key “ Data Reduction Protocol for Assessment of Erosion Parameters Using ISEP ,” MCE Project. January 2012

Products


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Thank You

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In Situ Erosion Evaluation Probe ( ISEEP )