Andover BF 0132(14) Alternatives Presentation Meeting FAS Route 132 - PowerPoint PPT Presentation

Andover BF 0132(14) Alternatives Presentation Meeting FAS Route 132 – Bridge #9 over Trout Brook October 22, 2018

Introductions Laura Stone, P.E. VTrans Scoping Engineer Gary Laroche, P.E. VTrans Project Engineer Carolyn Carlson, P.E. VTrans Design Project Manager

Purpose of Meeting  Provide an understanding of our approach to the project  Provide an overview of project constraints  Discuss alternatives that were considered  Discuss our recommended alternative  Provide an opportunity to ask questions and voice concerns

Location Map

Bridge 9 Project Location

Meeting Overview  VTrans Project Development Process  Project Overview – Existing Conditions – Alternatives Considered – Recommended Alternative  Maintenance of Traffic  Schedule  Summary  Next Steps  Questions

VTrans Project Development Process Initiated Project Project Contract Funded Defined Award Project Project Design Construction Definition  Quantify areas of  Identify resources & impact constraints  Environmental  Evaluate alternatives permits  Public participation  Develop plans,  Build Consensus estimate and specifications  Right-of-Way process if necessary

Project Overview  Existing Conditions  Alternatives Considered  Recommended Alternative

Description of Terms Used

Looking East over Bridge Existing Conditions – Bridge #9  Roadway Classification – Major Collector (Class 2 TH/FAS Route)  Bridge Type – 84’ Long Rolled Beam Bridge  Ownership – Town of Andover  Constructed in 1939

Existing Conditions – Bridge #9  Bridge 9 is Structurally Deficient due to the deck rating – localized spots with heavy deterioration, concrete spalling and large sections of exposed reinforcing steel. – Potential for full depth pop-outs  The rolled beams are in satisfactory condition, but have areas of heavy rust scaling, especially in the areas where deck spalling is present, and have minor section loss.  Both backwalls are failing with most of the concrete spalled with exposed reinforcing steel throughout. There is a potential for holes forming in the approaches due to the loss of roadbed material

Deck Deterioration Existing Conditions - Bridge #9  Deck Rating 4 (Poor)  Superstructure Rating 6 (Satisfactory)  Substructure Rating 5 (Fair)

Substructure Existing Conditions - Bridge #9 Skeletal Abutments   Failing Backwalls  Poor Condition bridge seats

Hydraulics and Environmental Resources Existing Conditions - Bridge #9  Class II Wetlands in Southeast Quadrant  Wildlife Corridor  Clear span meets required bankfull width

Existing Conditions

Design Criteria and Considerations  ADT of 830  DHV of 120  % Trucks: 19.6  Design Speed of 40 mph  Aerial Utilities

Alternatives Considered – Bridge #9  No Action – Additional maintenance required within 10 years  Deck Replacement – Structural deficiencies would be addressed – Widen to match the corridor – 30 year design life – Meets all ANR and hydraulic standards  Superstructure Replacement – Widen to match the corridor – 30 year design life – Meets all ANR and hydraulic standards  Full Bridge Replacement On Alignment – Widen to match the corridor – 75 year design life  Full Bridge Replacement Off Alignment – Widen to match the corridor – 75 year design life

Recommended Alternative - Bridge #9  Full Bridge Replacement – Widen to match the corridor – New integral abutments – 80’ span with skew similar to existing – 75 year design life

Proposed Typical Section

Proposed Layout Full Replacement On Alignment - Bridge #9  10’/3’ typical, 75 year design life

Proposed Profile

Maintenance of Traffic Options Considered  Offsite Detour  Phased Construction  Not an option for full bridge replacement  Temporary Bridge

Road Closure  Detour chosen and signed by Town  Shortest route is 6.4 miles end-to-end  8 week closure

Traffic Control – Offsite Detour  The shortest local detour route, has an End-to-End distance of 6.4 miles  Truck route available with end-to-end distance of 23.4 miles

What would be the maximum acceptable length of closure for Bridge #9? RAISE OF HAND A. 2 weeks B. 4 weeks C. 6 weeks D. 8 weeks E. 10 weeks F. 12 weeks G. No Preference

Temporary Bridge  One Lane Upstream Temporary Bridge with Traffic Signal Would require hillside cut ‐

Temporary Bridge Layout

Recommended Scope  Full Bridge Replacement with Traffic Maintained on an Offsite Detour – Widen to match the corridor – New integral abutments – 80’ span with skew similar to existing – 75 year design life – 8 week closure – No/Minimal Right of Way – No Utility Relocation – Construction Year: 2023

Alternatives Matrix Alternative 2 Alternative 3 Alternative 1 Alternative 4 Full Bridge Full Bridge Replacement On‐ Deck Replacement Superstructure Replacement Replacement Alignment Off‐Alignment Andover BF 0132(14) b. b. a. Offsite c. Phased a. Offsite c. Phased b. Temporary a. Existing Temporary Temporary a. Offsite Detour Construction Detour Construction Bridge Detour Bridge Bridge Bridge Total Project Costs $1,052,640 $1,454,335 $1,412,918 $1,449,294 $1,415,390 $1,248,928 $2,241,756 $2,044,398 $2,240,248 $35,090 $48,480 $47,100 $48,310 $47,180 $41,630 $29,890 $27,260 $29,870 Annualized Costs $26,316 $72,717 $70,646 $36,232 $70,770 $62,446 $112,088 $204,440 $224,025 TOWN SHARE 2.50% 5% 5% 2.50% 5% 5% 5% 10% 10% TOWN % Project Development 2 Years 4 Years 2 Years 2 Years 4 Years 2 Years 3 Years 4 Years 4 Years Duration 2 months 9 months 6 months 2 months 9 months 6 months 6 months 18 months 9 months Construction Duration Closure Duration (If 21 days n/a n/a 21 days n/a n/a 60 days n/a n/a Applicable) Typical Section ‐ Bridge 10'/3' (26') (feet) Geometric Design Criteria Substandard horizontal and vertical alignment at Approach No Relocation No No Relocation No No Relocation Relocation Utilities No ROW Acquisition No Yes No Yes No No Yes Yes 30 30 75 75 Design Life

Preliminary Project Schedule  Construction Start – 2023 – Total Cost Estimate: $2,241,756 • Estimated Town Share: $112,000

Next Steps – Bridge #9 This is a list of a few important activities expected in the near future and is not a complete list of activities. Wait for Town response to recommendation on proposed project  Develop Conceptual plans and distribute for comment  Request a Public Information meeting  Process local agreements  Right-of-Way process (if needed)  Town is responsible for any chosen detour route

Andover BF 0132(14) Questions and Comments FAS Route 132 – Bridge #9 over Trout Brook October 22, 2018