department of public works bureau of engineering & construction structural design section...

DEPARTMENT OF PUBLIC WORKSBUREAU OF ENGINEERING & CONSTRUCTION

STRUCTURAL DESIGN SECTION

REPLACEMENT OF BRIDGE NO. B-0427 ON DAIRY ROAD OVER OWL BRANCH

2014 Maryland Concrete Conference

Kevin J. Sabolcik, P.E.

Baltimore County DPW

David Berkhimer

Brawner Builders, Inc.

AN ECONOMIC APPROACH TO A SMALL BRIDGE REPLACEMENT PROJECT

OR

‘BRIDGE ON THE QUICK & CHEAP’



Problem Analysis – Decision Process

Design

Construction

Conclusion



What is a project?

A series of planned events undertaken in a systematic manner to achieve a specific outcome while balancing the constraints

of schedule, cost and performance or quality.





Existing Structure

• Built Circa 1920

• Concrete Slab w/Encased Steel Beam Superstructure

• Concrete Abutments on Spread Footings

• 16’ Long Span, 20’ Clear Roadway, 24’ Out to Out Width

Bridge No. B-0427 Dairy Road Elevation





Bridge B-0427 Dairy Road Approach



Interim Action



Structure Condition

• Overall Sufficiency Rating ≈ 38%

• Superstructure in Poor Condition

• Substructure in Satisfactory Condition

• Some Minor Lowering of the Stream Bottom along Abutments/Exposed Footings



Dairy Road Characteristics

• Rural Local Road (Northern Balt. Co.)

• Width Varied 16’ to 18”

• Tangential / Flat Alignment

• ADT ≈ 575 VPD/2% TRUCKS

• 30 MPH Design Speed

• No History Of Accidents At Site



Other Design Consideration

• Adjacent Overhead Utilities

• Soil Borings Indicated 10’ Silt/Sand Mix, 15’ Decomposed Rock then Rock

• No ROW beyond Existing Footprint

• USE III Waterway (10/1 to 4/30 Restriction)



Project Needs

• Need to Replace Deteriorated Structure

• Safety – Current Code (Loads, Widths, Barriers, etc.)

• Get In – Get Out – Stay Out



Project Wants

• Want to Avoid Right of Way Acquisition – Highest Priority

• Want to Minimize Permitting & Utility Issues – Secondary Priority

• Want Most Cost Effective Solution – Lowest Priority



Design Direction

• Leave Existing Abutments for Scour Protection & Minimize Stream Impacts

• Maintain Low Chord/Road Profile

• 24’ Clear Roadway Width (Design Exception Documented)

• Reinforced Precast Concrete Slabs

• Cast-in-Place Concrete Abutments on Micro-Piles.



Performance Specification for Pile

Foundation



Conclusions

• Total Project Cost ≈ $500,000

• Total Project duration < 12 Months

• Avoided ROW Issues by Discussing Project with Adjacent Property Owners

• Achieved Project Purpose



QUESTIONS???

Teamwork

department of public works bureau of engineering & construction structural design section...

Documents

width slide

site slide

restriction slide

mph design speed

dairy road approach

bridge b

place concrete abutments

existing structure