Michael P. Culmo, P.E.Vice President of Transportation and StructuresCME Associates, Inc., East Hartford, CT

CONNECTION DETAILS FOR PREFABRICATED BRIDGE ELEMENTS AND SYSTEMS

Learning OutcomesAfter completing this Module, you will be able to:• identify roadblocks to accelerated bridge construction• identify the resources for locating Connection Details for

PBES• describe features of PBES that improve the quality of the

finished product• recognize a typical construction schedule for a bridge built

with PBES• recall ways to save money by using ABC and PBES

Roadblocks to Accelerated Construction

The primary concerns that owner agencies have with respect to adopting accelerated construction techniques are:

• Need for Quality Details• Durability• Design Methodologies and Training• Construction Methodologies

“Connections Details for Prefabricated Bridge Elements and Systems”

• FHWA has developed this manual • This publication is intended to provide information

that will go a long way to answering all four of the previous concerns.

• Focus on details that have been used in the past.

“Connections Details for Prefabricated Bridge Elements and Systems”

Project Goals:

• Gather details of Connections that have been used on accelerated bridge construction projects

• Investigate transfer of technology from other markets into the bridge market

• Parking Garages• Stadiums• Buildings

“Connections Details for Prefabricated Bridge Elements and Systems”

All details need to pass a critical test before being published in the document:

• Does the connection result in a rapid construction process?• Does the connection transmit the forces between

elements effectively?• Is the connection durable?• Is it cost effective and easy to construct?• If a process or connection is proprietary, is there more than

one supplier?

• State DOT’s– Questionnaires sent via e-mail

• Federal Agencies• Researchers (previous and current)• Producers/Fabricators

Sources of Data

ForwardTable of Contents

Section 1General Topics

1.1Introduction

1.2Accel. Construction

Overview

1.3Applicability to Typical Bridges

1.4Typical Connection

Types

1.5Seismic

Considerations

1.6Materials

1.7Tolerances

1.8Fabrication and

Construction

Section 2Superstructure Connections

2.1Deck Systems

2.2Adjacent Butted Beam Systems

2.3Decked Stringer

Systems

2.4Modular

Superstructures

2.5Connections to Substructures

Section 3Substructure Connections

3.1Pier Systems

3.2Abutment Systems

3.3Wingwalls and Retaining Walls

Section 4Foundation Connections

Appendices

Appendix ANotations

Appendix BConnection Design

Examples

Appendix CStandard Products

Appendix DSample Const. Specifications

Appendix ECase Studies

Appendix FGlossary

Manual Organization

Connection Data Sheets

Precast Cantilever Abutments

Precast Integral Abutments

Precast Piers

Precast Piers

Precast Decks on PS Beams

Precast Decks on Steel Framing

Precast Decks

FRP Decks

Everything shown can be prefabricated

Total Bridge Element Prefabrication

Complete Bridge Element PrefabricationNew Hampshire Project• How fast can we build a bridge?• Experimental project• All components prefabricated• 115 foot span• Precast cantilever abutments• Clock started after old bridge

was removed• Roadway open to traffic in 8 days• Time Lapse Video on YoutubeTM • Search “Epping Bridge Construction”

Manual Distribution• Availability

– Published June 2009– Is available through FHWA

Highways for LIFE websitewww.fhwa.dot.gov/hfl/

Other Sources for Details• Utah DOT ABC Website

– www.udot.utah.gov (search ABC)– Piers, abutments, walls, decks

• PCI Northeast– www.pcine.org (Bridge resources)

• MassDOT– Working on new ABC manual

• NCHRP Report 681– Development of a Precast Bent Cap

System for Seismic Regions– Web search “NCHRP Report 681”

Schematic Design of a Prefabricated Bridge

Case Scenario• 4 lane bridge over an expressway• Existing bridge has deteriorated beyond repair• Heavy traffic on both roadways• A temporary bridge or staged construction is an option• The local business will accept a short term closure with

the detour• As opposed to a long term staged project• Establish the detour and accelerate the bridge

construction to less than 30 days

Existing Bridge

Leaking Deck Joints

Low Clearance

Salt spray attack from vehiclesSalt spray attack from vehicles

Existing bridge issues

Proposed Bridge TypeAfter a formal study, the owner opted for thefollowing structure criteria:

• Continuous steel girders (weathering steel)• Reduce to a two span bridge• Increase clearance by raising approach grades (3’)• Use integral abutments (no deck joints)• Composite concrete deck• Membrane waterproofing and Bituminous wearing surface• Open steel railings (galvanized)

Move substructures away from

roadway

No Deck joints

Build new piers and abutments in

new locations

Increase vertical clearance

Proposed Bridge

Sources of details- FHWA Connections manual: “Connection Details for Prefabricated Bridge Elements and Systems”

1. Review Chapter 1• Investigate connection types, materials, tolerances

2. Search applicable sections of other chapters for details

- NCHRP Report 681“Development of a Precast Bent Cap System for Seismic Regions”

- Utah DOT ABC Standards

Connection Types Chosen• The owner chose the following connection types

– Grouted reinforcing splice couplers• Quick, proven system• Can develop full bar strength• Simplifies the design process (same as CIP)

– Grouted PT Ducts• Provides significant adjustability at cap connection

– Grouted Voids• Corrugated metal pipe voids for integral abutments• Small blockouts for pinned connections (approach slabs)

– Concrete Closure pours between precast elements• Use for a limited number of connections (slower)

Grouted Reinforcing Splice Couplers• Emulates a reinforcing

steel lap splice• Multiple companies

– non-proprietary• Used in precast

parking garages, stadiums and bridges

• Installation video on youtube– Search “Georgia Pier

Construction”

Grouted Reinforcing Splice Connectors

NCHRP Report 681 Detail

Grouted PT Duct• Similar to grouted sleeves• Used in several states• Tested for high seismic regions• Significant adjustability• Details, specifications and design

information available

Footing to Sub-grade Connection

Footing to Footing Connection

Use CIP Closure Pour• Cast closure pour during structure erection• Design precast for structure DL• Design continuous footing for total loads

Footing to Column Connection

Column to Cap Connection

Use details from NCHRP Report 681

Completed Pier

Footing to subgrade

connection

Column to footing connection Column to cap connection

Footing to footing

connection

Abutment Details• Integral Abutment to piles

– Section 3.2.3.1 Precast Integral Abutment to Piles

• Corrugated metal pipe voids– Place over pile and fill with concrete

• Detail developed by Iowa DOT– Used in other states also

• Reduces element weight• Has large capacity to

transfer pile loads– Shear transfer via shear friction

Abutment to Pile Connection

Abutment Cap to Cap Connection

• Use Utah DOT Details– Concreted key– Use integral

diaphragm to link caps together

Approach Slab Connection

Completed Abutment

Pile to cap connection

Approach slab connection

Cap to cap connection

Beam to Deck Connection

Deck to Deck Connections

Deck to Deck Connections

Deck to Deck Connections

PC Deck Connection Details

Superstructure to Abutment Connection

Use CIP Closure Pour• Utah DOT Detail• Allows for significant

adjustability• Provides connection between

abutment stem elements

Integral Abutment ConnectionLongitudinal PT

Longitudinal crown

connection

Transverse slab

connection

Connection to beamCIP Curb

Completed Superstructure

Complete Bridge

Precast Integral Abutment

Membrane waterproofing with

bit. Wearing surface

Precast Pier

Precast full depth

composite deck

Estimated Construction ScheduleTask

Demo Existing Bridge

Install Foundations

Erect Beams

Install Deck and PT

Closure Pours

Curb Pour

Railings

Paving

Approach Roadway

Clean-up

5 Days

8 Days

3 Days

3 Days

3 Days

3 Days

3 Days

2 Days

17 Days

2 Days

Week 1 Week 2 Week 3 Week 4

Costs• Typical New Bridge (Cost=$175/sf) = $2,200,000

• Premium for ABC (assume 20%) = $440,000

• Temporary Bridge (Cost=$50/sf) = ($620,000)

Net Savings = $180,000

Note: These prices will vary greatly by region

Other Cost Savings• Ways to reduce bid prices with ABC

– Standardization– Programmatic (not one of a kind)– Reduced project site costs (trailers, etc.)– Reduced maintenance of traffic costs– Inflation

• Other Non- Bid Savings with ABC– Fewer police details– Reduced agency costs during construction (staff time)

• User Costs– Plus: $$ can be significant– Minus: $$ not in the budget

Quality• FL has had very good success with precast

piers in very harsh environments• CT has had Precast full depth decks in place

for over 20 years– Crack Free Deck– Excellent condition

• Integral abutments eliminate deck joints

By elimination of temporary bridges or costly stage construction schemes, and accounting for reduced agency costs

you CAN have all three

Rapid Construction

High Quality

Low Cost

You can only have any two

Old Adage

Conclusions• It is possible to build a complete bridge in 30 days (or less)• The FHWA manual provides a starting point for a complete

bridge prefabrication project• New details are coming on line all the time

– NCHRP Report 681, Utah DOT, PCI Northeast (www.pcine.org)

• You do not need to sacrifice quality to get rapid construction

• You can save money on an accelerated bridge project by:– Reducing construction time– Eliminate temporary bridges or staging

Module ConclusionsYou should now be able to:• identify roadblocks to accelerated bridge construction• identify the resources for locating Connection Details for

PBES• describe features of PBES that improve the quality of the

finished product• recognize a typical construction schedule for a bridge

built with PBES• recall ways to save money by using PBES

Questions

culmo@cmeengineering.com