SHRP2 Project R04

 Bridge Designs for ABC

Bala SivakumarHNTB Corp.

FHWA P2P ExchangeAug. 2012 Boston

SHRP2  Project R04PROJECT GOAL

To develop standardized approaches to designing, constructing, and reusing

complete bridge systems that address rapid renewal needs Phase I – Define ABC Challenges

Phase II – Identify & Refine the Best ABC Technologies

Phases III & IV – Standardize & Deploy ABC

Phase V – Beta testing of ABC Toolkit by VAOT

SHRP2 Project R04

INNOVATIVE BRIDGE DESIGNS FOR RAPID RENEWAL

2008 -- 2013

HNTB (Prime)Iowa State University

Structural Engineering Assoc. Genesis Structures

Dr Monica Starnes, Senior Program Officer SHRP2

Accelerated Bridge Construction (ABC)

Prefabricated Elements

Prefabricated Modular Systems

Structure Placement Methods

Accelerated Geo-tech Work

ABC ELEMENTS & METHODS

SHRP2 R04 -- Phases I, II, III (2008 – 2011)

Phase IV (2011-2013)

SHRP2 R04 ABC Toolkit

Expected Outcome: The designer, guided by the standard design concepts, details and the set of ABC design calculations will be better prepared to complete an ABC design for a routine bridge replacement project.

1 ABC STANDARD DESIGN CONCEPTS

2

3

4

ABC SAMPLE DESIGN CALCULATIONS

ABC ERECTION CONCEPTS

5 ABC CONSTRUCTION SPECIFICATIONS

ABC DESIGN SPECIFICATIONS (LRFD)

ABC Standard Design Concepts 

• Focus on conventional bridges• Complete bridges using prefabricated elements• Contractor could self-perform a lot of the work• Fabricate on site or in a plant and erect using 

conventional cranes• Fast assembly in the field in 1 to 2 weeks (Tier 3 

or less) • Durable connections / durable bridges 

GOALS:

Span Ranges for Superstructures• Simple / continuous spans from 40 ft to 130 ft. • Simple for DL ; Continuous for LL ; No Open Joints• Plans are grouped in the following span ranges: 

– 40 ft to 70 ft – 70 ft to 100 ft – 100 ft to 130 ft. 

• Spans to 130 ft can usually be transported and erected in one piece at many sites.

• Weight < 200 Kips  for erection using conventional cranes commonly used by contractors 

Prefabricated Decked Beam Elements

Deck Bulb Tees

Double Tees

Modular Decked Beams

2 Lane bridge with shoulders shown – customize width for site

Modular Decked Beams

• Barrier can be precast • Barrier load on exterior module

Prestressed Decked Girders

Based on the PCI NEXT beamSpans to 90 ftLow depth alternative

Decked Bulb Tee Span lengths from 40 ft to 130 ftUT, WA, ID among states with DBT standards

Adjacent Double Tee

Prefabricated Substructure Elements

ABUTMENTS & WINGWALLS– Semi Integral Abutments– Integral Abutments– Inline or U type Wingwalls– Supported on Piles and Spread Footings

PIERS– Precast Conventional Pier– Precast Straddle Bent– Drilled Shaft and Spread Footing Options

Integral and Semi-Integral Bridges for Rapid Renewal

• Well suited for ABC 

• They allow the joints to be moved beyond the bridge 

• Close tolerances required when utilizing expansion bearings and joints are eliminated 

• The backwall is precast with the deck. 

• Fast erection in 1 to 2 days, economical

Semi-Integral AbutmentSuspended Backwall

• H piles or spread footings• Fill pile pockets with SCC• Easy fit-up in the field

Precast Piers

Conventional Pier

Straddle Bent

• Deep foundation may be outside existing footprint

• Non-prestressed so contractor can self-perform precasting 

• Fast erection using grouted splice couplers

ABC Connections• Connections affect field assembly time. 

• Goal is rapid field assembly and long-term durability of joints

• Also, flexural continuity between modules to emulate CIP construction

• Connections affect seismic performance 

• REFERENCE: FHWA Connections Manual

Connections for ABC– Ultra High Performance Concrete (UHPC) 

longitudinal & transverse joints between superstructure modules

– Grouted splice couplers in piers replace the typical lap splice

– Self Consolidating Concrete (SCC)  pile connections and abutment to wingwall connections

……………………………………………………………………………………– Grouted cap pockets / grouted ducts for 

substructure connections (seismic)– Other rapid set concrete options may be used

Grouted Splice Coupler

•   Allows rapid construction. No post tensioning required• UHPC joints are typically 6 in wide. Good durability•   Can be reinforced with hairpin bars or straight bars 

UHPC Joints in Bridge Deck

(Longitudinal Joint. Longitudinal steel not shown)

Erection Concept Drawings• Erection using conventional cranes. • Erection using ABC construction technologies adapted 

from long span construction

Erection Concepts for Prefabricated Elements

Erection Concepts for Bridge Replacement Using Cranes

Short Single Span over Stream Cranes selected for 90 Kip pick

Longer Span over RoadwayWeight up to 200 kips

Erection with ABC Construction Technologies

• Use ABC construction technologies where ground access for cranes below the bridge may be limited.

• Conventional cranes with enough reach 

• ABC technologies that allow construction from above:

– Above Deck Driven Carriers – Launched Temporary Bridge– Transverse Gantry Frames– Longitudinal Gantry Frames

Above Deck Driven Carriers

Allows fast rate of erection

Rides on existing bridge, new bridge (check capacity to support)

Ideal for bridges with many spans. long viaducts

Launched Temporary Bridge• Sites with limited ground access or long spans• Launched across or lifted over a span to act as a “temporary 

bridge” • Used to deliver the heavier modules without inducing large 

erection stresses.• Temp bridge can also support transverse gantry frames

Gantry Frames

Longitudinal Gantry Frame

Transverse Gantry Frame

• The LRFD Design Specifications do not explicitly deal with the unique aspects of large scale prefabrication

• In some cases, the most extreme load case may occur during shipping and handling.  

• The work in SHRP2 R04 entailed the identification of any shortcomings in the current LRFD Bridge Design Specifications

• Recommendations are provided for addressing these limitations. 

ABC Design Specifications for LRFD

ABC Sample Design Calculations• Three ABC design examples for prefabricated systems 

in the toolkit:– Modular Decked Beams– Decked Precast  Prestressed  Girder– Precast Pier

• Design Criteria:• AASHTO LRFD (5th Edition)• Supplemental ABC criteria

The design examples provide guidance on the overall structural design of bridge components for ABC

LRFD for ABC Design• The design of most ABC elements and systems 

follows traditional LRFD design specifications. 

• Design the ABC elements and the completed structure using all applicable LRFD Limit States 

• Additional requirements apply for ABC connections, lifting and moving of prefabricated elements and modules.

Decked Steel Girder Design for ABC

• Three Stages for Design     Prefabrication Stage (many support options)

– Load Case 1 = Dead load on module steel section only– Load Case 2 = Dead load on module composite section Erection Stage (many lift options)– Load Case 3 = Modules are lifted into place Final Stage– Load Case 4 = Modules are assembled and made continuous

» DL» FWS» LL + IM» Utilities 

• Recommended Special Requirements for ABC • Focus heavily on means and methods requirements for rapid 

construction. 

Proposed Section in LRFD Construction Specifications

XX.1 GENERALXX.2 RESPONSIBILITIESXX.3 MATERIALSXX.4 FABRICATIONXX.5 SUBMITTALSXX.6 QUALITY ASSURANCEXX.7 HANDLING, STORING, AND TRANSPORTATIONXX.8 GEOMETRY CONTROLXX.9 CONNECTIONSXX.10 ERECTION METHODSXX.11 ERECTION PROCEDURES

ABC Construction Specifications 

First Demonstration Project Demonstrate Use of ABC Concepts Developed

in SHRP2 R04Keg Creek Bridge, Iowa

– Total prefabricated bridge– ABC design concepts & details developed in SHRP2 R04 

Project were used with minimal customization for the site

14 day ABC period Opened Nov 1, 2011

SHRP2 R04 ABC Demonstration Project #2Lateral Slide (NYSDOT)

2012/ 2013 ConstructionOvernight replacement

I-84 EB & WB Bridges over Dingle Ridge Road

Closing• New generation PBES for ABC are economical to 

construct and designed for durability• SHRP2 R04  ABC Toolkit and training materials will be 

available to provide guidance to those new to ABC and the use of PBES

• SHRP2 R04 demonstration projects showcase the use of the Toolkit

• SHRP2 R04  ABC Toolkit to be available soon• The time for ABC is now