www.schnabel.comWe Support the Earth®

Ohio River Tunnel:Secant Pile Shafts

www.schnabel.comWe Support the Earth®

CSO Concept

www.schnabel.comWe Support the Earth®

Problems withCombined Sewer Overflows

www.schnabel.comWe Support the Earth®

Nationwide CSOs

www.schnabel.comWe Support the Earth®

Local Sewer Systems

www.schnabel.comWe Support the Earth®

Overall Project Plan View

www.schnabel.comWe Support the Earth®

Secant Pile Shaft Locations

www.schnabel.comWe Support the Earth®

Tunnel Profile

www.schnabel.comWe Support the Earth®

Tunnel Profile

www.schnabel.comWe Support the Earth®

Secant Shaft Profiles

www.schnabel.comWe Support the Earth®

Basic Design Concept

• Rigid Wall• Minimal deflection• Use Ko

• Water table• Ground surface

• Tolerance• Piles – 0.5%• Out of Round – 0.25%

www.schnabel.comWe Support the Earth®

Effective Thickness

www.schnabel.comWe Support the Earth®

Effective Thickness

www.schnabel.comWe Support the Earth®

Effective Thickness

www.schnabel.comWe Support the Earth®

Hoop Stresses

www.schnabel.comWe Support the Earth®

Design: Finite Element Analysis

• FEM to analyze:• Unbalanced loading

• Crane• Conveyor Belt Footings

www.schnabel.comWe Support the Earth®

Quality Control:Verticality Monitoring

www.schnabel.comWe Support the Earth®

Quality Control:Concrete Strength

www.schnabel.comWe Support the Earth®

Quality Control: Cores of Cores

www.schnabel.comWe Support the Earth®

Quality Control: Concrete Volume

www.schnabel.comWe Support the Earth®

Construction: Template

www.schnabel.comWe Support the Earth®

Construction: Large Drill Rig, Casing and Support Equipment

www.schnabel.comWe Support the Earth®

Construction: Overburden, Rock Drilling

www.schnabel.comWe Support the Earth®

Construction: Weather Extremes

Winter – 0o Summer 100o

www.schnabel.comWe Support the Earth®

Finished Face of Secant Piles

www.schnabel.comWe Support the Earth®

Secant Pile Shafts: A Means to an End (or start of a Tunnel)

www.schnabel.comWe Support the Earth®

Credits