183A Turnpike:

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183A Turnpike A Design-Build Success Story
Authors Lisa Carter Powell, PE President,
P.E. Structural Consultants, Inc. Arthur
Champlin, PE Structures Department Manager,
URS Corporation
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The Project Story.

• Project Intro
• Structural Design Highlights
• Aesthetic Design Highlights
• Design-Build Experiences (from the Structural
  Engineers perspectiveof course!)

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The Project
Quick Facts 11.6 miles of New Toll
Road Design-Build Delivery 238 Million
Construction Cost Design Began January
2005 Opened to Traffic March 2007
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The Players
Owner Central Texas Regional Mobility
Authority (CTRMA) Builder Hill Country
Constructors (Granite-Abrams JV) Designer URS
Corporation Structural Subconsultant P.E.
Structural Consultants, Inc.
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The STRUCTURES

• 23 Bridges (spanning roadways, railroads,
  drainage areas and creeks)
• 40 MSE (Mechanically Stabilized Earth) Walls
• 4 Noise Walls (2 supported on bridges)
• Overhead Sign Supports and Electronic Toll
  Gantries
• Miscellaneous (Drainage and Traffic Structures)

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Typical Overpass
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Typical Ramp
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Typical Creek Crossing
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Typical Sign Structure
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Structural Design Highlights
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Bridge Design Features

• Typical Bridges - Prestressed Concrete I-Beam
  Units
• Integrated Aesthetic Design
• Pre-LRFD (17th Edition AASHTO Standard Specs)
• Long Spans pushing Type IV and Type VI limits
• Karst Geology
• Tall Columns

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Bridge Superstructures

• Type IV Workhorse
• Poor-Boy Units
• Avg Spans 115, 120 up to 134 at Overpasses
• Higher Concrete Strengths
• 0.6 Strands
• PCPs (Precast Concrete Panels)

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Bridge Substructures

• Aesthetic Multi-Column Bents
• Economical Column to Drilled Shaft transition
• Same basic Bent Cap Section at all Bents
• Minimized unique form sets required
• Constant cantilevers
• 50-90 bridge widths, 0-39 degree skews
• Cap depth variations w/ same form
• Tall columns stepped for addl capacity at base
  (same cap)

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Typical Drilled Shaft/Column Transition
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Tall Stepped Columns
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Park Street Bridge

• Landmark Bridge for Project
• Standardized Details (with a twist)
• Type VI (MOD) w/ (Almost) Record Span (158.7)
• Fc 9,000 psi
• 0.6 strand
• Special Bracing
• Special Abutments

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Park Street Beams and Bracing
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Park Street Abutment
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Aesthetic Design Highlights
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Aesthetic Design Goals

• Visual Identity
• Compatibility w/ projects nearby
• Consistency for all Structural Elements
• Constructability
• Economy
• Environmental Sensitivity

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Aesthetic Project Identity

• Chisholm Trail Parkway..

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Critical Factors for Aesthetic Success

• True Collaborative Effort afforded by D-B
• Designers, builders, form mfrs, suppliers,
  owner/reps, public all accessible during process
• Prioritization and timing keyed to design and
  construction schedule
• Integration of Structural and Aesthetic Design
• Codependent relationship of structural efficiency
  and constructability to aesthetic details
• Mainlane bridges are key
• Aesthetics applied frugally

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Aesthetic Bridge Bents

• Sculpted shape, patterns
• Stylized longhorn motif
• Clean, simple lines

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Aesthetic Abutments and Retaining Walls

• Vertical Abutment Walls
• Aesthetic Corner Elements (MSE Panels)
• Special C-I-P Coping
• Limestone Formliner or smooth finish
• Framed panel for CTRMA Logo
• Artwork at key locations

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Aesthetic Abutment/Retaining Wall
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Abutment Art - Concept and Execution
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Aesthetic Sign Structures and Gantries

• Aesthetic concrete columns w/ std Sign Trusses
• Aesthetic cues from Bridge Columns
• Precast Enclosures
• Gantry concept from Sign Bridges

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Aesthetic Sign Structures and Toll Gantry
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Aesthetic Noise Walls

• Precast Post and Panel
• Aesthetic cues from Bridge Columns
• Finishes from Retaining Walls
• Property Owner input on residential side finish

Aesthetic Noise Wall Concept
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Color Ties it all together

• Subtle use of Color
• Palette emulates Natural Limestone
• Similar to aged Concrete
• Cost-effective uniformity with Paint

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Design Build Experiences
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Accessibility and Collaboration

• Key participants co-located in Project Office
• Ready access to information
• Fosters accountability, responsiveness,
  efficiency, coordination
• Fosters inter-discipline understanding
• Intense (but not always!)

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Design Deliverables Schedule, Review and QA/QC
Process

• Traditional Submittals modified to accommodate
  construction schedule
• Early Release Grading and Bridge Substructure
• Reviewville and Acronym City
• DCR, CR, ITR, OTS, DQCM, QC Audit, DQAF, TxDOT
  and GEC Reviews all proceed RFC to HCC!!!
• Over The Shoulder Reviews particularly
  effective

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Post-Design Services

• Accelerated procedures to resolve RFIs, NCRs
• Effective in minimizing delays
• Informal contact first
• Contractor proposed solutions
• Follow-up w/ formal trail
• On-call availability key

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How the story ends

• Compressed schedule achieved
• Award Winning Project
• Well-received by community toll revenues nearly
  double predictions in first year
• Revenues funding additional improvements
• One of our all-time favorite projects!

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Thank You!
Questions?