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Design-Built Permanent Soil Nail Retaining Wall and Building Foundations at the University of

Connecticut Health Center

Ulrich La Fosse, P.E. GeoDesign, Inc.

Middlebury, CTNew York, NYWindsor, VT September 13, 2013

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Site Locus

SITE

Bridging Documents –Foundations and Wall Types

ACC Building – Drilled Shafts

Garage – Spread Footings

Site Wall Behind Garage• Temporary SOE• Buttress Type – Concrete Gravity Wall• Heights up to 55 feet & 450 feet long

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Bridging Docs Retaining Wall - Plan

Section 15-Ft24-Ft500-Ft

GRAVITY WALL

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Bridging Docs Retaining Wall - Section

GRAVITY WALL

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Bridging Docs Temporary SOE & Wall

CONCRETEGRAVITY

WALL

TEMPORARYSOE WALL

Alternate Design Goals

Accelerate Construction

Eliminate work

Achieve economies

Meet Owner Criteria

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Alternate Design Concept

Combine Temporary & Permanent Support of Excavation

Replace Drilled Shafts with shallow Foundations (ACC)

Maximize Foundation Pressures (Garage & ACC)

Retaining WallDesign Considerations

Sparse Subsurface Data Very Tight Schedule for Design Tall Wall (up to 55 feet High) Wall Surcharge (1.5H:1V slope and

Road) Bridge Abutment Loading Combine Temporary & Permanent

Support of Excavation

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Surficial Geology

SITE

Retaining WallConstruction Considerations

Sparse Subsurface Data Tall Wall (up to 55 feet) Wall Surcharge (1.5H:1V slope and

Road) Bridge Abutment Loading Combine Temporary & Permanent

Support of Excavation

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EXISTING 2H:1V SLOPE

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Main Road and Traffic Surcharge

STEEP SLOPE ABOVE WALL

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Retaining WallPerformance Considerations

Must Limit Movement

Permanent Wall Considerations

Wall Finish – Varying Opinions

Alternate Design ConsiderationsACC Building

High Bearing Pressures Desirable Variable Soil Conditions

• Unsuitable Fill, over• Moderately dense Glacial Till, over• Dense to very Dense Till

Reworked Site – Possible unexpected variations and organics

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Permanent Soil Nail Wall Design

Partial Soil Wall Nail Plan

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Typical Soil Nail Wall - Section

Typical Soil Nail Wall - Section

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Typical Soil Nail Wall - Section

Typical Soil Nail Wall - Section

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Typical Soil Nail Wall - Section

Partial Soil Nail Wall – Elevation

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Soil Nail Wall – Detailed Section

CAPACITY OF TEMPORARYFACING IS NEGLECTED IN FINAL DESIGN

Start of Wall Construction

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DCP Soil Nailsand Temporary Shotcrete

Wall Facing

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IT IS IMPERATIVE TO BE ABLE TO CONTROL WATER and SOILS MUST BE ABLE TO STAND UNTIL SHOTCRETE HAS BEEN APPLIED

SLOUGHING SOILS

DRAINAGE, DRAINAGE, AND MORE DRAINAGE!

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A DCP SURPRISE!

A SIMPLE SOLUTION TO THE VEXINGPROBLEM OF LACK OF DCP AT TOP OF NAIL

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ANOTHER SURPRISEAN UNEXPECTED STUMP DUMP!

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Installation of Reinforcement for Final Shotcrete Wall Facing

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Application of Final Shotcrete Wall Facing

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Night Work to MeetProject Schedule

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Completed Wall

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Micropile-Supported Bridge AbutmentDirectly Behind

Permanent Soil Nail Wall

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Footing Preparationat ACC Building

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Thank You!

Questions?