Recent Fast Track Projects:Challenges, Successes & Lessons Learned

AASHTO Sub-Committee on Design Meeting

April 28, 2010

The Ben Sawyer Bridge Design/Build Rehabilitation Project

Project History

The historic Ben Sawyer Bridge was built in 1945 to carry locals and visitors between the east cooper barrier islands of Sullivan’s Island and Isle of Palms with Mount Pleasant and the rest of the Charleston area. For years, it was the only vehicular access for both Sullivan’s Island and the neighboring Isle of Palms. The Isle of Palms Connector was completed in 1993 and provided additional access to both Sullivan’s Island and the Isle of Palms.

The Ben Sawyer Bridge drew significant national attention when Hurricane Hugo came ashore in the Charleston area in 1989. The storm essentially picked up and rotated the swing span, leaving it tilted at a 45-degree angle, which created one of the lasting images of the hurricane’s devastation. The swing span was lifted back into place on October 5, 1989. One lane of the bridge was re-opened to traffic on October 8, 1989.

Project History

Ben Sawyer – Post Hugo

Advantages of Accelerated Bridge Construction vs Traditional Construction

Traffic Congestion Traditional construction requires a 12-month, 11-mile

detour through the Isle of Palms and Mt. Pleasant.

ABC requires a 10-day detour. ABC avoids approximately 12 months of additional

traffic congestion in both the Town of Mt. Pleasant and the Isle of Palms.

ABC reduces crash potential. ABC reduces motor user costs. ABC provides much greater access to both Sullivan’s

Island and the Isle of Palms.

Advantages of Accelerated Bridge Construction vs. Traditional Construction

Quality of Work ABC improves the quality of work by constructing the swing

span in an off-site controlled atmosphere. The use of ABC further improves the quality by having the

majority of the swing span’s electrical and mechanical components installed off-site as well.

Preliminary functional testing can be completed off-site without interference of the motoring public.

Marine Traffic ABC has much less impact to the intra-coastal waterway and

its’ users.

Design/Build Contract Highlights

Project Duration – 540 days

Liquidated Damages - $2,900/day over 540 Days

DBE Goal – 5%

5-Year project warranty

Warranty Bond ($5 Million)

Professional Liability Insurance ($3 Million)

Design/Build Contract Closure Requirements

Duration – 10 days for Total ClosureClosure Restrictions –

Prohibited between April 1st and October 1st. Prohibited between December 15th and January 3rd.

Incentive Pay - $2,500/hour up to 48 hours.Disincentive - $2,500/hour over 10 days with no cap.Swing Span fully operational

Construction

Contractor – PCL Civil Constructors, Inc. Construction Manager – PB Americas, Inc. Designer – Hardesty & Hanover, LLP Owner – SCDOT FHWA – 100% oversight project

Ben Sawyer Bridge

Temporary Access & Supports

Approach Spans

Approach Spans

April 28, 2010

Roller System

April 28, 2010

Construction of Swing Span Off-site

Transporting of Swing Span

Old Swing Span being removed

New Swing Span ready for placement

New Swing Span being placed

Emergency Contract for I-77 NB and SB Lanesover S-12-56 (Chester County)

Replacement of Cracked Steel Plate GirderMain Spans

April 29, 2010 cracks in the webs of steel plate girders were found by the District 4 Bridge Inspection Team at I-77 NB and SB over S-12-56 in Chester County

Bridge Maintenance Office verified the severity of this condition, which did not exist as of the previous normal inspections 2 years ago

It is believed that the primary causes for the cracked girders on I-77 are the following: thin web plates (<1/2”), these were 3/8” diaphragm and stiffener web plates were only welded to the web and top flange thus causing an

inordinate amount of torsion to be carried more directly by the web

Weld

No weld Diaphragms offset due to skew

Project Timeline

Other factors contributing to the cracking were: bridge skew torsional fatigue and possible overall fatigue possible overheating of the steel substrate due to multiple weld passes on the web to flange

connection during fabrication material mechanical properties (to be verified by testing) construction loadings during I-77 construction could have reduced the fatigue life

Emergency Declaration was approved by SCDOT Secretary of Transportation Limehouse on May 3, 2010 met two qualified bridge contractors on site May 4, who were given information that required the contractors

to bid on temporarily shoring and replacing both steel plate girder main spans District 4 closed the ramps and overpass/S-12-56 on May 5, 2010 and began work to improve the on and off

ramps which were used for the detour Bids were received on May 10, 2010 and an accelerated contract cost and schedule was negotiated on May

11, 2010 with the project low bidder, United Contractors

Project Timeline

Temporary shoring was installed beginning May 12, 2010 to allow traffic to continue using the bridges until closed for work

Temporary Shoring

Project Timeline

Project Timeline

Bridges were closed on June 7, 2010 and demolition of the main spans began.New girders were set beginning June 11, 2010

Project Timeline

Deck pours started midweek of June 14, 2010

Project Timeline

Both spans were completed by June 28, 2010 Bridge Maintenance performed a project final inspection on June

28, 2010 Bridges were opened 2 days later on June 30, 2010

Project Activity

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Ramps were reopened for normal use on July 23, 2010

Project Timeline

I-385 Rehab Project

Project Scope& Schedule

Interstate Rehabilitation of I-385, approximately 15 miles, with 10” of high strength concrete

Raising of 6 overpass bridges

Bridge replacement of fly-over bridgethat connects I-26 westbound to I-385 northbound

Shoulder widening with roller compacted concrete

I-385 northbound detoured; construction duration condensed from 3 years to 7 ½ months

Traffic Control Plan

Northbound Detour Relatively low ADT (17,600 to 21,900) within project corridor Existing pavement width (32’) insufficient to stage or run head to

head traffic Parallel interstate in close proximity for detour traffic (15 mi./15 min.) Good network of regional primary routes for local traffic

Detour Benefits Safety increased by separating motorists from construction

operations Construction operations streamlined with closure; allowed pavement

of full width PCC up to one mile per day (weather permitting) Estimated $34.6 million in savings compared to traditional

construction staging over multiple years

Keys to Success

Affected businesses, elected officials, and state trucking association contacted months prior to closure

Brochures and maps were distributed at local Rest Areas and project website was established with detour information

Contractor was required to hold Public Information Meeting prior to closure

Pre-construction and mid-construction partnering meetings

Contract had $25,000 daily incentives not to exceed $750,000 and $50,000 daily liquidated damages with no cap beginning August 16, 2010

Construction Related Keys to Success

Bridge jackings were let in separate contract and completed prior to I-385 northbound closure

Project let five months in advance of closure date for prep work and material fabrication (fly-over bridge superstructure)

All excavation was converted to Site Excavation

Concrete paving machine guided by laser total station with an automatic dowel inserter

Leica Scan Station 2 survey scanner used to verify cross-slope correction

I-385 Southbound Mainline Paving Operations

Concrete Paving Machine

Total Station Prism for Paving Machine Guidance

Concrete Finishing

Roller Compacted Shoulder Paving

Fly-Over Bridge Replacement