current research on slope stabilization with in-situ reinforcement j. erik loehr department of civil...
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Current Research on Slope Stabilization with In-situ Reinforcement
J. Erik Loehr
Department of Civil EngineeringUniversity of Missouri - Columbia
Ongoing Research Projects
Slope Stabilization Using Recycled Plastic Pins– Missouri Department of Transportation– Epoch Composite Products– The Judy Company
Stabilization of Earth Slopes Using Reticulated In-situ Reinforcement– National Science Foundation
In-situ Reinforcement of Slopes
Railway
Slip Surface
Soil Nails
ReticulatedMicropiles
Firm Stratum
Fill
Stiff ClayRelic ShearSurface
Soil Dowels
after Bruce and Jewell, 1986
SoilNails
Shotcrete
Key Issues being investigated
Limiting soil pressure – Influence of member spacing– Influence of member size
Axial vs. lateral load transfer– Influence of member orientation– Effect on overall stability
Group/network effects
Field Demonstration Sites
SiteSlope Angle
General Characteristics
I-435 (Wornall Rd.) 2.2:1 Zoned embankmentI-435 (Holmes Rd.) 2.5:1 Zoned embankmentUS 36 (Stewartsville) 2.2:1 Zoned cutI-70 (Emma) 2.5:1 Homogeneous fillUS 54 (Fulton) 3.2:1 Homogeneous cut
All surficial failures!!
US36 Stewartsville Site Layout4.5' x 3' 6' x 6' 6' x 4.5' 4.5' x 6'
54 pins 67 pins 78 pins161 pins
slope crest
slope toe
30 ft6 ft
Approx. Slide Extent
Instrumented Members
Purpose of Large-scale Tilt Box
Intermediate to full-scale field tests and centrifuge testing
Will permit– Rapid evaluation of alternative reinforcement
scenarios and methods at near field scale– Construction using “field-like” equipment– Calibration of numerical models