Sunday Creek Bridge #364C October 8, 2008 Spokane, WA Doug Walters, P.E. King County DOT Sunday Creek Bridge Replacement Utilizing Geosynthetic Reinforced.

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


Project Location


Existing Log Stringer Bridge


Bridge Deck


Typical Bridge Traffic Prior to Load Restrictions


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


West abutment temporary shoring

I-Beam on Ecology Blocks


East Abutment Temporary Shoring

Shoring Support


Typical rot on log stringers


Superstructure: Prefabricated Steel Truss


Superstructure Selection

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

• additional environmental permitting

• Narrow Haul Road


Superstructure: Prefabricated Steel Truss

3ft clear space


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


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


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


BRIDGE LAYOUT

22 ft

PLAN

104 ft

25 ft

14 ft


GRS ABUTMENT DETAIL

FINISHED GRADE LINE


CMU Block Schedule

11 ft

23 ft

5 ft

11 ft

9 ft

36 ft


Tasks to be completed

• Finalize Design

• Bid January 2009

• Construction June 2009


THANK YOU!Question?

Sunday Creek Bridge #364C October 8, 2008 Spokane, WA Doug Walters, P.E. King County DOT Sunday Creek Bridge Replacement Utilizing Geosynthetic Reinforced.

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