NEW PILE WALL PROGRAM NEW PILE WALL PROGRAM Joe Carte Larry Douglas
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
NEW PILE WALL PROGRAMNEW PILE WALL PROGRAMJoe Carte
Larry Douglas
OverviewOverview• Beta Phase
Th G l• The Goal• Brief History• Some Theory & Demonstration• Surveying and MappingSurveying and Mapping• Drilling and Sampling
W t C B i• Worst Case Basis• Example• Screen Shots of Program
The GoalUser Friendly
Windows InterfaceSoil Parameters Directly from Blow Count and Rock Mass Rating (RMR)Rock Mass Rating (RMR)
Potentially Save Money Nobody Wants Thisy yPile LengthUses Plastic Modulus
LRFD CompliantUses Factored Load and Factored Resistance
Material’s DOS ProgramMaterial s DOS Program
HP10x57 (S=58.8)
District 6’s Spread SheetDistrict 6 s Spread Sheet
Dr George Hall’s ProgramDr. George Hall s Program
S=39.4
HP10X42 (S=43.4)
Dr Ashour’s ProgramDr. Ashour s Program
Plastic Modulus Z=48.3
Some TheorySome Theory
• Limit-Equilibrium Stability AnalysisLimit Equilibrium Stability Analysis
• Strain Wedge Model
• Structural Analysis
Limit-EquilibriumLimit EquilibriumFS = Resisting Force / Driving Force = CL + (N – U) tan g g ( )α / W sin α = 1.0 For Limit Equilibrium
T=Driving Force
R R i ti FR=Resisting Force
W
(From Hall, 2006)
Limit-EquilibriumLimit Equilibrium
• Back Analysis = Large Scale Lab Test ofBack Analysis = Large Scale Lab Test of Failure Surface
Original Geometry
Existing Geometry
Original Geometry and Ground Water at Failure ≈ Peak Phi (φp)Existing Geometry
and Ground Water ≈ Residual Phi (φr)
(φ )
Basic Strain Wedge in Uniform soilBasic Strain Wedge in Uniform soil
Loading from Slide
x
Pτ
Resistance from Soil/Rock Below Failure Surface
Pile Width (D)Slice of Wedge at Depth x
(From Ashour, 1998)
Structural AnalysisStructural Analysis
• LRFDLRFD– Strength Limit State
• Flexure (Plastic Hinge Failure Mode)( g )– Service Limit State
• Check Deflection (The Max Δ Depends . . .)– Flexure Formula
• MPlastic Mr = Φ Mn = Mp = Φ Fy x Z• MYi ld M = Φ M = My = Φ F x S• MYield Mr = Φ Mn = My = Φ Fy x S
• Φ = 0.9 (Table 11.5.6-1)( )
Design ApproachesDesign Approaches
Just Move the Road
CutOriginal
Sl S f
Fill
Slope Surface
Design ApproachesDesign Approaches
Design ApproachesDesign Approaches
Slide AnalysisSlide Analysis• First
• Determine Geometry of Slide Mass• Soil Strength Parameters• Water Level
• Utilize the Stability Analysis• Back calculationac ca cu at o• Obtain a Factor of Safety of 1.0• Determine Pile Size and LengthDetermine Pile Size and Length
Surveying and MappingSurveying and Mapping• Must have a field survey y
• A minimum • “Worst Case”
Cross Section• 20-ft beyond
• Entire Slide Area• Entire Slide Area• 20-ft beyond
• Visible WaterVisible Water • Drainage• Other FactorsOther Factors
Simple SurveySimple Survey
• Abney Level and TapeAbney Level and Tape
Complete Survey CrewComplete Survey Crew
Example of Good Survey
Required InformationRequired Information
• Depth to RockDepth to Rock• Depth to Water Table
• Water Level (Keep in Mind Climatic Conditions)Water Level (Keep in Mind Climatic Conditions)
• Soil Moisture• Depth to Slip SurfaceDepth to Slip Surface
• Moisture• Soil StiffnessSoil Stiffness• Inclinometers
• Commercial• Home-made
InclinometersInclinometers
• Slip PlaneSlip Plane
Drilling and SamplingDrilling and Sampling
• Estimate Soil/Rock ParametersEstimate Soil/Rock Parameters• N-Values• Cathead v Auto Hammer• Cathead v. Auto Hammer
• 60% efficiency for rope and cathead hammers • 80% efficiency for the auto hammer80% efficiency for the auto hammer
• Core Samples• RMR DataRMR Data
– Log Joint Spacing and Condition
Boring Logs• N ValuesN Values• Water Level• Soil Change• Rock Depth• Soil Moisture
RQD• RQD
RMRRock Mass HCSI
Rating (RMR)HCSIRQD• Example:
• qu = 1,440 KSF • RQD = 49%
RQD
Joint Spacing &• RQD = 49%• Spacing = 2-Ft• Condition =
Joint Spacing &Condition
• Slicken-Sided• Water = Moist Only • RMR 7+8+20+6+7• RMR 7+8+20+6+7
= 48• USED IN PSSLOPE
PROGRAMWATER
PROGRAM
Gravel, loose
Shaley Clay, ms, moist
Shaley Clay, s, slightly moist
Clayey Shale (Possible Weathered Shale), vs, dry
Arenaceous Shale, H
•BOH 461.2-ft
Soil and Rock B d iBoundaries
Point Coordinates
Line NumbersLine Numbers
Line NumbersLine Numbers
Coordinate SystemCoordinate SystemPSSLOPE: starts at zero
Layers and Soil Type D iDocumentation
Failure Points
Failure Points
Failure Plane
Failure Plane
Failure Plane
Desired FOS
1.3
Simple Wedge Function
Related Documents
