Sunday Creek Bridge #364C

October 8, 2008Spokane, WA

Doug Walters, P.E.King County DOT

Sunday Creek Bridge Replacement Utilizing Geosynthetic Reinforced Soil (GRS) Abutments

Sunday Creek Bridge #364C

Project Location

Sunday Creek Bridge #364C

Existing Log Stringer Bridge

Sunday Creek Bridge #364C

Bridge Deck

Sunday Creek Bridge #364C

Typical Bridge Traffic Prior to Load Restrictions

Sunday Creek Bridge #364C

Deficiencies

Structural• Timber cribbing abutments & log stringers damaged• Minor scour• 1997- Placed temporary shoring

– load limit of 3 tons

Environmental• Cited by the WA Department of Fish and Wildlife

– Temporary shoring within stream channel

Sunday Creek Bridge #364C

West abutment temporary shoring

I-Beam on Ecology Blocks

Sunday Creek Bridge #364C

East Abutment Temporary Shoring

Shoring Support

Sunday Creek Bridge #364C

Typical rot on log stringers

Sunday Creek Bridge #364C

Superstructure: Prefabricated Steel Truss

Sunday Creek Bridge #364C

Superstructure Selection

• Hydraulic Opening – Above 100 year flood elevation – Changing road grade

• additional environmental permitting

• Narrow Haul Road

Sunday Creek Bridge #364C

Superstructure: Prefabricated Steel Truss

3ft clear space

Sunday Creek Bridge #364C

Foundation ConsiderationsBorings • Alternating layers of medium dense alluvial gravel, sand,

and silt

Abutment Foundation • Shallow foundation• Base of foundation below stream’s thalwag elevation

Sheet Pile Cutoff Walls • Allow dry construction• Provide additional scour protection

Sunday Creek Bridge #364C

GRS Abutment Selection

Constructability• Avoid long concrete haul• Not weather dependent• Reduced time of construction

Cost Savings• Materials• General labor• Standard equipment

Environmental• No concrete placement

Sunday Creek Bridge #364C

GRS Abutment Design Outline

• King County preliminary GRS abutment – NCHRP Report 556 “Design and construction of GRS

abutments”

• Mike Adams (FHWA) reviewed & refined design – Provided GRS design detail with layout

– continue to provide evaluation, design, and construction support

Sunday Creek Bridge #364C

BRIDGE LAYOUT

22 ft

PLAN

104 ft

25 ft

14 ft

Sunday Creek Bridge #364C

GRS ABUTMENT DETAIL

FINISHED GRADE LINE

Sunday Creek Bridge #364C

CMU Block Schedule

11 ft

23 ft

5 ft

11 ft

9 ft

36 ft

Sunday Creek Bridge #364C

Tasks to be completed

• Finalize Design

• Bid January 2009

• Construction June 2009

Sunday Creek Bridge #364C

THANK YOU!Question?