ABC/PBES COSTS
by
Mary Lou Ralls, P.E., PrincipalRalls Newman, LLC
(formerly Texas State Bridge Engineer)
Learning Outcomes• Identify examples of ABC/PBES replacement projects that
achieved onsite construction time and cost savings, and locate project contacts
• Describe combinations of PBES and contracting strategies that achieved accelerated onsite construction timelines at lower costs
• Explain why comparison of ABC costs and conventional construction costs may not be appropriate
• Explain why moving to ABC/PBES as a standard practice will achieve cost savings
• Reduced onsite construction time
• Construction cost less than engineer’s estimate
• Project details• Project owner contacts• Other contacts, e.g.:
• Contractor• Design Engineer• Prefabricator
http://www.fhwa.dot.gov/bridge/prefab/successstories/091104/index.cfm
Cost-Competitive Projects
ABC/PBES Projects
• ABC/PBES Deck Elements: full-depth precast deck panels– WA – Washington State Department of
Transportation’s SR 433 Lewis & Clark Bridge over Columbia River - 2004
• ABC/PBES Pier Elements: precast caps on cast-in-place columns– TX – Texas Department of Transportation’s State
Highway 66 Bridge over Lake Ray Hubbard - 2003
ABC/PBES Projects, cont’d.
• ABC/PBES Beam Elements: modular beams with decks– NJ – New Jersey Department of Transportation’s
Route 1 Bridges over Olden Avenue & Mulberry Street – 2005
• ABC/PBES Beam Elements (modular beams with decks) + Abutment Elements (precast backwalls, precast wingwalls)– CO – Colorado Department of Transportation’s State
Highway 86 Bridge over Mitchell Gulch – 2002
ABC/PBES Projects, cont’d.
• ABC/PBES Beam Elements (modular beams with decks) + Pier Elements (precast pile caps) + Miscellaneous Elements (precast approach slabs, precast parapets– NY – New York City Department of Transportation’s
Belt Parkway Bridge over Ocean Parkway – 2004
ABC/PBES Deck Elements (full-depth precast deck panels)
Replaced 3900 ft of deck using SPMTs during 124 nights plus 3 weekend closures …
… with no impact to rush-hour traffic
After deck replacement
SPMTs with frame carrying panel
State Route 433 Lewis and Clark Bridgeover Columbia River, WA/OR – 2004
State Route 433 Lewis and Clark Bridgeover Columbia River, WA/OR – 2004
Removal of old deck section & installation of new panel in avg. 6.5 hours overnight
103 full-width, 6-inch full-depth precast lightweight concrete panels, each 36 ft wide & 20 ft to 45 ft long
SR 433 Lewis and Clark Bridge over Columbia River Contract Requirements
• “A” + “B” + “C” Bidding Method to determine lowest responsible bidder– “A” = bid items – “B” = bridge closures @ $8,000– “C” = single lane closures @ $2,000
SR 433 Lewis and Clark Bridge over Columbia River
Incentives for Early Completion• $100,000 for completion by April 2004• $55,000 per Weekend Bridge Closure less than 4• $4,000 per Total Bridge Closure less than number bid• $1,000 per Single Lane Closure less than number bid
SR 433 Lewis and Clark Bridge over Columbia RiverLiquidated Damages
• $16,000 per Total Bridge Closure more than number bid
• $4,000 per Single Lane Closure (SLC) more than number bid
• $1,700 per 15-min period beyond times specified for Weekend or Total Closure
• $900 per 15-min period beyond SLC
• Engineer’s Estimate $ 28.8 M• Number of bidders 6• 2nd lowest bid $ 29.2 M• Low Bid $ 18.0 M• Savings – 38 % = $ 10.8 M
Closures: Only 124 nights & 3 weekends
SR 433 Lewis and Clark Bridge over Columbia River – 2004 Construction Costs
ABC/PBES Pier Elements:precast caps on cast-in-place columns
Precast bent caps saved 215 days of onsite construction
State Highway 66 Bridgeover Lake Ray Hubbard, Texas – 2003
State Highway 66 Bridgeover Lake Ray Hubbard, Texas – 2003
…proposed by the Contractor
43 identical precast concretebent caps …
State Highway 66 Bridge over Lake Ray Hubbard Contract Requirements
• Contract specified cast-in-place concrete bent caps• Contractor proposed field change to precast concrete
bent caps for eastbound bridge• TxDOT accepted proposed field change, with no
change in funding
State Highway 66 Bridge over Lake Ray Hubbard – 2003 Construction Costs
• Engineer’s Estimate $ 48.2 M• Number of bidders 8• 2nd lowest bid $ 43.1 M• Low Bid $ 40.9 M• Savings – 15 % = $ 7.3 M
Onsite Time Savings: 215 Days
ABC/PBES Beam Elements (modular beams with decks)
Route 1 Bridges over Olden Avenue& Mulberry Street, New Jersey – 2005
NJDOT’s 1st Hyperbuild Project
Olden Avenue Mulberry Street
Route 1FreewaythroughCity ofTrenton
Replaced 3 deteriorated bridges in 3 weekends
Deteriorated Route 1 decksover Mulberry Street and Olden Avenue
Route 1 Bridges over Olden Avenue& Mulberry Street, New Jersey – 2005
New Route 1 decksover Mulberry Street
Elevation of new Route 1 Bridgesover Mulberry Street
over Mulberry Street
over
Old
en A
venu
e
Route 1 Bridge Construction
Route 1 Bridges over Olden Avenue & Mulberry Street Contract Requirements
• For each bridge, maximum 57 hours from complete closure to 2 lanes open
• Lane Occupancy Charge up to $10K/da• Substantial Completion by November 16, 2005• All work completed by January 13, 2006
• If less than 57 hours:– Bridge over Olden Avenue• $1,500 per hour• Cap of $27,000
– Each bridge over Mulberry Street• $2,000 per hour• Cap of $36,000
Route 1 Bridges over Olden Avenue & Mulberry Street Incentives
• If more than 57 hours:– Bridge over Olden Avenue• $1,500 per hour
– Each bridge over Mulberry Street• $2,000 per hour
• If after Nov. 16 – $4,200 per day• If all work not completed by Jan. 13 – additional $900
per day
Route 1 Bridges over Olden Avenue & Mulberry Street Liquidated Damages
• Engineer’s Estimate $ 3.8 M• Number of bidders 5• 2nd Lowest Bid $ 3.8 M• Low Bid $ 3.5 M• Savings – 8 % = $ 0.3 M
3 bridges replaced in 3 weekends
Route 1 Bridges over Olden Avenue & Mulberry Street – 2005 Construction Costs
ABC/PBES Beam Elements (modular beams with decks) + Abutment Elements
(precast backwalls, precast wingwalls)
46-hour weekend construction of 40-ft long, 43-ft wide single span
No impact to rush-hour traffic
State Highway 86 Bridgeover Mitchell Gulch, Colorado – 2002
Precast concrete abutments, wingwalls, superstructure units with railing, & steel H piles
Early Saturday morning Saturday afternoon Saturday afternoon
State Highway 86 Bridgeover Mitchell Gulch, Colorado – 2002
State Highway 86 Bridge over Mitchell Gulch Contract Requirements
• Contract specified 3-cell cast-in-place concrete box culvert to replace 2-span timber bridge
• Value engineering change proposal by contractor/design team– Prefabricated single-span bridge – Completion in one weekend
State Highway 86 Bridge over Mitchell Gulch Contract Requirements, cont’d.
• CDOT response:– Accepted VE change proposal– Implemented lane rental fee
• Lane Rental Specification– $500/hr starting 6 a.m. Monday– Fee based on user costs to occupy SH 86
State Highway 86 Bridge over Mitchell Gulch – 2002 Construction Costs
• Engineer’s Estimate $ 394.2 K• Number of bidders 12• 2nd Lowest Bid $ 365.8 K• Low Bid $ 365.2 K• Savings – 7 % = $ 29.0 K
Closure: Only 46 hours
ABC/PBES Beam Elements (modular beams with decks) + Pier Elements (precast pile caps) + Miscellaneous
Elements (precast approach slabs, precast parapets)
Existing Interchange
Belt Parkway Bridge over Ocean Parkway, New York City (Brooklyn) – 2004
Reconstructed Interchange
Replaced existing 2-span, 149-ft long, 78-ft wide bridge with 3-span, 221-ft long, 134-ft wide bridge …
… with no lane closures during peak traffic hours
Belt Parkway Bridge overOcean Parkway, New York City (Brooklyn) – 2004
Prefabricated:– Piles– T-Walls– Cap Beams– Superstructure– Parapets & Barriers– Approach Slabs
Belt Parkway Bridge over Ocean Parkway– 2004
51 superstructure segments in new 221-ft long x 134-ft wide bridge (49’-107’-65’)
Belt Parkway Bridge over Ocean ParkwayContract Requirements
• “A” + “B” Bidding Method to achieve reduced onsite construction timeline– “A” = bid items – “B” = “Critical Duration” x $85,000
Belt Parkway Bridge over Ocean ParkwayIncentives/Disincentives
• Incentive for completion before “Critical Duration”:– $85,000 per day– Cap of $2,000,000
• Disincentive for completion after “Critical Duration”:– $85,000 per day– No dollar limit
Belt Parkway Bridge over Ocean ParkwayConstruction Costs
• Engineer’s Estimate $ 60.0 M• Number of bidders 5• Low Bid $ 47.9 M• Awarded Bid * $ 55.5 M• Savings – 8 % = $ 4.5 M
* Best Value: only 285 “Critical Duration” days
Did these projects cost lessthan conventional construction?
ProjectEngineer’s Estimate
Awarded Bid
Cost Savings$ %
WSDOT Lewis & Clark Bridge $ 28.8M $ 18.0M $ 10.8M 38TxDOT SH 66 Bridge
over Lake Ray Hubbard48.2M 40.9M 7.3M 15
NYCDOT Belt Parkway Bridge 60.0M 55.5M 4.5M 8NJDOT Rt. 1 Bridge 3.8M 3.5M 0.3M 8
CDOT Mitchell Gulch Bridge 0.394M 0.365M 0.029M 7Totals $ 141.2M $
118.3M$ 22.9M 16%
avg.
So, what is needed to ensurecost savings or, at a minimum,
cost competitivenesson ABC/PBES projects?
For Effective ABC Implementation
• Make ABC standard practice, not just project-specific use– Shows owner’s commitment to future use – a
program of work– Reduces costs with multiple use
• Example: Utah DOT transition to ABC as standard practice for projects as appropriate
$0
$100,000
$200,000
$300,000
$400,000
$500,000
$600,000
$700,000
$800,000
$900,000
$1,000,000
I-215; 4500South
I-80; StateStreet to
1300 East
I-80; Mt.Delle toLambsCanyon
3300 Southover I-215
I-15;Widening,
500 North toI-215
PioneerCrossing
SP
MT
Co
st
Cost
Log. (Cost)
Cost per bridge span moved
Cost of implementing SPMT Bridge Moves
-19 Utah Bridges
Module ConclusionYou should now be able to:• Identify examples of ABC/PBES replacement projects that
achieved onsite construction time and cost savings, and locate project contacts
• Describe combinations of PBES and contracting strategies that achieved accelerated onsite construction timelines at lower costs
• Explain why comparison of ABC costs and conventional construction costs may not be appropriate
• Explain why moving to ABC/PBES as a standard practice will achieve cost savings
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