design matrix for emergency landslides · instructions for sizing piles in the field by...
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Design Matrix For Emergency Landslides
Joe CarteUnit Leader ‐Geotechnical Engineer
The Problem: WV had over
200Emergency
Landslides that Originated from the March 3rd
Flooding Event
32 Counties in March 3rd Declaration
Most of the 200 Slidesare in 5 Counties
FEMA Declarations this Year
Access Blocked to Homes =Emergency
Mr. Wentz Showing his Best Side
Our Geotechnical Unit had
2Weeks
to Provide25
Designsfor this
Emergency Declaration
Our Geotechnical Unit Mark Nettleton
GeotechnicalEngineer
Aaron WentzEngineering Geologist
George ChappellEngineering Geologist
Bob BarclayEngineeringGeologist
Ryan YoungGeotechnician
Our Unit is Busy with Our Regular Duties
We Design Repairs for Major Landslide/Rockfalls for all 10 Districts
We Write GeotechnicalReports for the WVDOH In‐House Design Section
We Review Consultants’Geotechnical Reports and Foundation Designs
Some of Our Regular Duties Include:
The Remainder of the Emergency
Landslide Repairs were, and continue
to be, Designed By the Districts
and Consultants
And Our Unit ‐We are Now up to about 30 Emergency Landslide Designs
Can We Drill the Slide Sites? NO!
Instrumentation? Out!
One Lane Width
3 Different Bedrock Depths
High, Medium, &, Low Groundwater
Levels
Assumed Soil & Rock Parameters
So We looked at Several Typical Scenarios as Follows:
We Also Modeled
a 28 feet Road Width and
Looked at the Different Rock
Depths
Our Goals Was to Determine the Maximum Exposed Wall Height (Stick‐up)
for 3 Common Pile Sizes (HP10x42, HP12x53, & HP14x73) in each Scenario
PSSLOPE Program ‐ Input Window
Simple Wedge Analysis
Pile Performance Ratio – Ok at FS= 1.25
4 inches Deflection is OK for Rural Roads ‐ Service Limit State (FS=1.0)
The Stick‐Up Matrix Using 3 Pile Sizes for One & Two Lane Widths and Various
Depths to Rock and
GroundwaterLevels
Instructions for Sizing Piles In the Field by ExperiencedWall Designers
• HP10x42 = 12 feet wall height• HP 12x53 = 14 feet wall height• HP 14x73 = 17 feet wall height
• If you see rock at the bottom of the wall location, then you can add 2 feet to each of these max stick‐upheights.
• If the hillside is steep below the wall location or you may lose some of the passive wedge, upsize the pile.
Example Emergency Landslide
Slide LengthTie into Existing Walls
Exposed HeightQuantities
Notes
Write Up Sheet
The Sketch
Fill in The Blank Splice Detail
Title Page
Quantity Estimate
Sketch and Notes
Typical Details
Typical Wall Profile & More Details
Wale Details
Questions
Thank Youfrom theIn-house
GeotechnicalUnit