National Value Engineering Award

Pre-Construction

Engineering

less than $25 million

Most

Value Added

Proposal

Presented by the AASHTO Value Engineering Technical Committee

August 4, 2015

Montana Department of Transportation

Flathead River – 3 Miles North West of Big Fork

For Demonstrating Outstanding Value Engineering Achievements

in Teamwork, Cost Savings, Enhanced Performance, or Expedited Project Delivery

that Resulted in an Overall Improved Business Practice

FLATHEAD RIVER BRIDGE 3 MILES NW BIGFORK

2015 AASHTO VE CONFERENCE

PRESENTATION

PRE-CONSTRUCTION ENGINEERING (<$25M)

OVERVIEW • LOCATION:

– Northwestern Montana near the towns of Big Fork and Somers

• Located over the Flathead River

• Transition between flat terrain and rolling hills

• PURPOSE AND NEED:

– Improve safety and mobility by replacing the functionally obsolete structure and the bridge approaches

– The structure ranked high for seismic retrofit because of its fracture critical two-girder system

OVERVIEW - continued

• PROPOSED SCOPE:

– New alignment

– Construct new 736 foot, 3 span bridge

– Complex 1.4 mile reconstruction project

• ORIGINAL PROJECT COST = $24.3M

OVERVIEW - continued

• CONSTRAINTS: – 4(f) Fish Wildlife and Parks – fishing access site

– Environmental issues (wetlands, bull trout, etc.)

– High risk Right of Way acquisition

• CONSIDERATIONS: – New offset alignment

– Liquefaction may occur during a high seismic event at the end bents

– Deep Water Foundation constructability

– Flathead County Master Trail Plan

VE/VA STUDY RECOMMENDATIONS

• 1A - New Alignment or Existing - Evaluate Bridge Foundation Types

• 1B - New Alignment – Evaluate Ground Improvements Beneath Approach Embankments

• 2A - Existing Alignment – With Detour Bridge During Construction

• 2B - Existing Alignment – With Road Closure During Construction

• 3A - Either Alignment – Eliminate Shared Use Path • 3B - Either Alignment – Design For Future Expansion

For Shared Use Path

RECOMMENDATION #1A – New Alignment -

Evaluate Bridge Foundation Types

Other Options

• 3-72” Diameter Piles

• 2 Rows of 5-48” Diameter Piles for additional stiffness

• 2-96” Diameter Piles for accelerated construction

• Must meet “no rise” requirement

RIVER BOTTOM CROSS-SECTION

Recommendation #1B – New Alignment – Evaluate Ground Improvements Beneath Approach

Embankments

Improve Soil Properties Using Compaction Grouting Original Design: Stone columns used to mitigate potential for liquefaction and lateral spreading at both abutments. Proposed Change: Improve the soil properties at both abutments using compaction grouting. Justification: Compaction grouting improves soil density and increases soil strength. Anticipated reduced mobilization cost and less equipment, can limit treatment to target zone in soil profile, can stage grout pattern/ hole layout as needed. Decreased construction time. POTENTIAL COST SAVINGS = $0.7M

Recommendation #3B – Either Alignment – Design For Future Expansion For Shared Use Path

• Build bridge foundation and superstructure to accommodate future Shared Use Path

• Construct Path when trail connection is constructed

• Potential Cost Savings = $0.91 M • Current design does not include a path along the length of the

project

The Study Team applied the principals and practices of the Value Engineering Job Plan which resulted in cost reduction and performance benefits in the following areas:

• Cost & schedule savings as compared to original design

• Project improvements as compared to original design

• Improved constructability

Total potential cost savings of $9.73 million, a 40% reduction in the total project cost

SUMMARY • 30-35% reduction in the construction schedule is

anticipated • Innovative techniques to solving complex geotechnical

design • Maintained safety and traffic operations • Reduced Environmental, R/W and Fishing Access site

impacts • Reduced work zone impacts to users • Improved constructability of the bridge • 2 value added ideas:

– Add lighting or conduit to shared use path along the structure

– Extend the separated path along the length of the project to include the fishing access