alderfer road (t-423) bridge replacement project...total replacement of the bridge carrying alderfer...

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PREPARED BY MCMAHON ASSOCIATES

Alderfer Road (T-423) Bridge Replacement Project

Lower Salford TownshipMontgomery County, PA

December 2, 2020

Transportation Solutions Building Better Communities

• Project Purpose and Need• Project Funding Sources• Overview of the Existing

Conditions• Overview of the Proposed

Improvements• Construction Staging• Traffic Control During

Construction & Detour Plan• Project Schedule including

Construction

ALDERFER ROAD (T-423) BRIDGE REPLACEMENT PROJECT



PROJECT PURPOSE & NEEDTotal Replacement of the bridge carrying Alderfer Road over the West Branch of Skippack Creek. 3 primary design objectives:

1. Replace the existing structurally deficient bridge that is in poor condition;Structurally Deficient Definition: Bridge is restricted to light vehicles, closed to traffic or requires

rehabilitation. There are elements of the bridge that need to be monitored and/or repaired and the bridge must be inspected and maintained.

2. Improve horizontal and vertical roadway geometry in the vicinity of the bridge;

3. No rise in water surface elevation during the base flood event. The project site is located in a FEMA Zone AE w/floodway.

AE: High-risk areas have at least a 1% annual chance of flooding. Area inundated by the Base Flood with Base Flood Elevations (BFE) determined. BFE: The elevation of surface water resulting from a flood that has a 1% chance of equaling or exceeding that level in any given year.


Township Owned Structure – Township is responsible for maintenance and improvements. PennDOT completes annual inspections on behalf of the municipality for structures with a 20-foot span or greater. (Structures with a span between 8’ to 20’ are solely Twp responsibility).

Lower Salford received an award through the 2018 PA Municipal Bridge Retro-Reimbursement Program (MBRP)• Includes Federal and State funding as part of the Transportation Improvement Program

(TIP); a regionally agreed upon list of transportation projects as required by federal law;• MBRP is a reimbursement program that allows the Township to submit for reimbursement of

up to 80% of the total project cost;• The reimbursement is made at the end of the project construction;• The reimbursement can include project development, construction, and inspection

services.


PROJECT FUNDING SOURCES


Existing Structure Type• Two-span, 40’ long reinforced concrete slab

bridge; • Built in 1940; • Currently posted for 15 Tons;• Supported on a concrete pier and

concrete abutments with integral wingwalls.• Inspected annually by PennDOT.

Regular Flooding Events• May 29, 2019 Storm Event (Photos);• Existing structure cannot pass the 2-year

storm event.


EXISTING CONDITIONS


Proposed Structure Type• 51’-6” span, prestressed concrete composite adjacent box beam bridge;• Opening large enough to pass the 100-year storm event;• No change in elevation to the 100 year flood plain as result of the construction;• Bridge parapet walls and guide rail meeting current requirements;• Architectural treatment will be provided on parapet walls and safety wings;• Structural Adequacy approval is required by PennDOT, even though this is a Township structure.

• Existing Bridge


PROPOSED IMPROVEMENTS

Architectural treatment example only; Henry Woods Bridge

Existing Bridge

Proposed Bridge


Roadway Geometry• Maintain 10’ travel lanes plus adding 5’ shoulders within limits of work;• Horizontal geometric improvements to meet posted speed design criteria; superelevation for the

travel lanes; • Vertical profile adjustments to allow for large enough bridge opening; Includes raising the low

section of the roadway approximately 5 feet.


PROPOSED IMPROVEMENTS

EXISTING

PROPOSED


Environmental Studies & Permitting • Chapter 105 Joint Permit issued by DEP for the structure replacement and work area

Stream Channel Grading

Adjustments to Adjacent Properties• Access adjustments, include re-profiling to tie into the new roadway elevation;• Shared-use path replacement;• Grading modifications.

Utility Relocations • Cooperation and coordination with the Lower Salford Township Authority (LSTA), PECO Gas, PECO

Electric, North Penn Water Authority (NPWA)


PROPOSED IMPROVEMENTS CONT’D


Four Stages of Construction• Coordinated with Bridge, Roadway, and Erosion and Sedimentation Control requirements

Stage 1 – West Side of the Bridge (Sta. 7+50 to Sta. 12+10)Duration: 10 Weeks


CONSTRUCTION STAGING


Stage 2 – East Side of the Bridge (Sta. 12+10 to Sta. 13+20)Duration: 10 Weeks




Stage 3 – East Side of the Bridge (Sta. 12+20 to Sta. 16+50 & Wyndham Court) Duration: 10 Weeks

Stage 4 – Final Improvements (Final Paving, Markings, etc.) Duration 2 Weeks





FINAL CONDITION


Bridge and Roadway will be constructed under a Detour• Local access to properties and businesses along

Alderfer Road will be maintained during construction;• Detour Route will be Ruth Road, Clemens Road, Main

Street;• Advance notice variable message boards will also

be provided by the Township alerting public of upcoming detour;

• Detour approved by PennDOT.


TRAFFIC CONTROL AND DETOUR PLAN

And Remember This:


Project Development (2018-2020)• MBRP Application, preliminary engineering, environmental studies and permitting, hydraulic and hydrology

analysis, final design, structural approvals, utility coordination, property owner coordination/Right-of-Way and Temporary Construction Easement acquisition.

Project Advertisement/Letting (January 2021 – March 2021)• Publicly advertised using PennBID which simplifies the municipal letting process;• Bid package available to large amount of qualified contractors• Anticipated Award March 3, 2021 BOS Meeting

Project Construction (April 2021 – November 2021)• Anticipated Pre-Construction Meeting Mid-Late March 2021• Notice-to-Proceed April 2021 • Construction Duration Approximately 8 Months, Utility Coordination Schedule is Critical


PROJECT SCHEDULE


QUESTIONS?CONTACT INFORMATION:

Stephanie L. Butler, P.E., Senior Project ManagerMcMahon Associates, Inc. [email protected], Ext. 1256

Christopher Seaman, P.E., CBI, Senior Project Manager (Structures)McMahon Associates, Inc. [email protected]

mailto:[email protected]

mailto:[email protected]

alderfer road (t-423) bridge replacement project...total replacement of the bridge carrying alderfer...

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