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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 PART 2 – SITES EARTH SPILLWAY EVALUATION B. Earth Spillway Integrity Analysis b. Characterization of geologic materials: iii. Characterizing the Headcut Erodibility Index (Kh) 2) for Cohesionless Soils SPECIALTY WORKSHOP: SITES TRAINING AND INTRODUCTION TO WINDAM ASDSO Dam Safety 2008 Earth Spwy Evaluation
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Objectives State the common range of the Kh parameter for soils Identify plot of rate of headcut migration versus Kh parameter and explain sensitivity of plot to values of Kh Using example soil data, assign a value to the Kh parameter accurately Identify tests used to characterize soils for estimating the Kh parameter Earth Spwy Evaluation 2
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Typical values for the Kh Factor
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Typical values for the Kh Factor 0.01 Soil 0.2 Weathered Rock 0.5 Soft or Jointed Rock 10 Hard Rock Earth Spwy Evaluation 3
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Available Tools For Estimating Kh
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Available Tools For Estimating Kh NEH 628, Chapter 52, Appendix B Soil Catalog on SITES CD Earth Spwy Evaluation 4
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Chapter 52, Appendix B - Soils
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Chapter 52, Appendix B - Soils If the PI greater than 10 – Cohesive If the PI is < 10, soil is Cohesionless Earth Spwy Evaluation 5
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Soil Weathered Rock Poor Quality Rock 0.2 Earth Spwy Evaluation 6
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Available Tools For Estimating Kh
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Available Tools For Estimating Kh Spreadsheet Uses soil properties from field and laboratory tests or table estimates NEH 628, Chapter 52, Appendix B Soil Catalogue Earth Spwy Evaluation 7
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Examples of Catalog Soils
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Examples of Catalog Soils Catalogue Soils are on SITES CD Earth Spwy Evaluation 8
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Soil Catalog Existing catalog for soils (assuming that Kh value is < 0.2) is ten samples Only Three Cohesionless Soils. Catalog listings with Kh values of 0.01 to 0.03 for cohesionless soils Experience with recent Oklahoma spillway shows Kh values may be less than 0.01 for nonplastic non-cemented sands. Earth Spwy Evaluation 9
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Soil Catalogue Soil descriptions are very brief Some wording confusing – example index value based on laboratory strength notation for nonplastic ML soil from Oklahoma Earth Spwy Evaluation 10
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Only Three Cohesionless Soils in Catalogue Earth Spwy Evaluation 11
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Kh – 0.01 Buck and Doe Run 33, MO SM, very loose sand with little bonding;deep deposit Earth Spwy Evaluation 12
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Kh – 0.02 Rush Creek 45, Oklahoma ML, cohesionless, headcut; index value based n laboratory strength test Earth Spwy Evaluation 13
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Chapter 52, Appendix B Is the PI greater than 10 – Cohesive If the PI is < 10, soil is Cohesionless Following summary next discusses cohesionless soils Earth Spwy Evaluation 14
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Kh – 0.03 Big Sand 3, MS ML, some apparent bonding; headcut Earth Spwy Evaluation 15
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Material Strength Number, Ms
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Material Strength Number, Ms For Cohesionless Soils Values for Kh and Ms are related to relative density estimates and SPT values (Table 52-2) Earth Spwy Evaluation 16
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Table 52-2. Ms for Cohesionless Soils
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Table Ms for Cohesionless Soils Relative Density Ms Very loose < 0.02 Loose 0.02 – 0.05 Medium Dense 0.05 – 0.10 Dense 0.10 – 0.20 Very Dense 0.20 – 0.45 Earth Spwy Evaluation 17
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Field Estimates for Relative Density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Field Estimates for Relative Density Relative Density Very Loose Loose Medium Dense Very Dense Description 1/2” Reinforcing rod can be pushed easily by hand into soil Earth Spwy Evaluation
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Field Estimates for Relative Density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Field Estimates for Relative Density Relative Density Very Loose Loose Medium Dense Very Dense Description Can be excavated with a spade. A wooden peg 2”x 2”can easily be drive to depth of 6 ”. Earth Spwy Evaluation
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Field Estimates for Relative Density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Field Estimates for Relative Density Relative Density Very Loose Loose Medium Dense Very Dense Description Easily penetrated with a 1/2” reinforcing rod driven with a 5 pound hammer Earth Spwy Evaluation
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Field Estimates for Relative Density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Field Estimates for Relative Density Relative Density Very Loose Loose Medium Dense Very Dense Description Requires a pick for excavation. Wooden peg 2”x 2”is hard to drive beyond 6 ”. Earth Spwy Evaluation
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Field Estimates for Relative Density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Field Estimates for Relative Density Relative Density Very Loose Loose Medium Dense Very Dense Description Penetrated only a few centimeters with a 1/2” reinforcing rod driven with a 5 pound hammer Earth Spwy Evaluation
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Other estimates for relative density
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Other estimates for relative density Estimate Relative Density from SPT tests Field Tests – Based on Reinforcing Rod and Wooden Stake Dynamic Cone Penetrometer Earth Spwy Evaluation 23
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Dual Mass Dynamic Cone Penetrometer
SITES Workshop-Phoenix, AZ Mar 31-Apr 2, 2009 Dual Mass Dynamic Cone Penetrometer Earth Spwy Evaluation 24
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 very dense – Kh > 0.20 Dense – Kh = 0.10 – 0.20 Medium – Kh = 0.05 – 0.10 Loose – Kh = very loose – Kh < 0.02 Earth Spwy Evaluation 25
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SITES Workshop-Phoenix, AZ
Mar 31-Apr 2, 2009 Summary The rate of upstream migration of a headcut predicted by the SITES program is extremely sensitive in the range of values of the Kh parameter which are typical for soils Cohesionless soils (PI < 10) have typical values of Kh less than 0.05 Earth Spwy Evaluation 26
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