Mockingbird Pedestrian Bridge presentation

Mockingbird Bridge

Pre-Bid Meeting 3/31/2011

MOCKINGBIRD BRIDGE

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REDLINE BRIDGE • Cantilever Abutment

Note: Images are not from DART tunnels.

•Prefabricated truss bridge • Installation over DART Redline Track • Ultralight approach structure

MOCKINGBIRD BRIDGE : REDLINE BRIDGE

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DART TRACKS

MOCKINGBIRD BRIDGE

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MOCKINGBIRD BRIDGE : BURIED UTILITIES

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DART AGREEMENT TERMS • Equivalent Load Limits over Tunnel

MOCKINGBIRD BRIDGE LOAD LIMITS – OVER DART TUNNEL

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DART AGREEMENT TERMS • Equivalent Load Limits at Retaining Wall & Portal MOCKINGBIRD BRIDGE : LOAD LIMITS – AT DART RETAINING WALL

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DART AGREEMENT TERMS • Equivalent Load Limits at Redline Retaining Wall MOCKINGBIRD BRIDGE : LOAD LIMITS – REDLINE BRIDGE

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DART AGREEMENT TERMS

TRAFFIC CONTROL - CLOSURES

• Load Limits apply to temporary props

• Mockingbird Station Exit & parking spaces

•Limited window for work over recessed tracks (Catenary lines de-energized)

•Palomar hotel service drive •Lane closures during non-peak hours

MOCKINGBIRD BRIDGE : TEMPORARY PROPS & TRAFFIC CONTROL

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ULTRALIGHT FILL APPROACH STRUCTURES •Over-excavation to 6 ft below grade • Expanded Polystyrene Fill (EPS) •1 ft Thick concrete deck & corner blocks

•Cementitious wall coating

MOCKINGBIRD BRIDGE : ULTRALIGHT APPROACH STRUCTURES – EPS

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ULTRALIGHT FILL APPROACH STRUCTURES •Redline Bridge – West side •220 LF / max 5ft height •Mockingbird Bridge •North Approach 170 LF •South Approach 415 LF •Height varies to 17 ft max

MOCKINGBIRD BRIDGE : ULTRALIGHT APPROACH STRUCTURES – REDLINE BRIDGE

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MOCKINGBIRD BRIDGE

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MOCKINGBIRD BRIDGE

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MOCKINGBIRD BRIDGE

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MOCKINGBIRD BRIDGE

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MOCKINGBIRD BRIDGE

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Design Concept • Structural System – Standard rolled sections (W12) – Precast deck panels

(no formwork over roadway) – Cables (locked coil) – Micropiles

• Kit of Parts • Offsite Prefabrication – Minimize On Site Work – Maximize Fabrication Efficiency

MOCKINGBIRD BRIDGE

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ELEVATION

DART TRACKS

PLAN MOCKINGBIRD BRIDGE : KEY PLAN & ELEVATION

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Back Stays

ELEVATION

Bumper

PLAN MOCKINGBIRD BRIDGE : BRIDGE GEOMETRY

TOWER 19

86 Micropiles, bond zone 20-feet long Shallow rock (14-feet) Nominal capacity: 540 kips (T) and 622 kips (C) Tension piles prestressed Compression piles: 9 5/8” dia. casing

Small equipment Minimized noise and vibration MOCKINGBIRD BRIDGE : MICROPILES

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•Offset from micropile footing •Buried beam •Concrete Sub-base •Guided disk bearings

•Back walls (placed last)

Top of Unweathered Rock

MOCKINGBIRD BRIDGE : ABUTMENTS

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Steel Pipe API 5LX-56 Standard section 36”OD x 1.25” th. Plates ASTM A709 HPS GR70 Single crane pick

Inclined, stabilized with backstays Approx. 98 feet

Concrete-Filled Tube

Approx. 77°

MOCKINGBIRD BRIDGE : TOWERS

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Pour Backs

Adjustable Anchors

Concrete Sub-base Top of Unweathered Rock

MOCKINGBIRD BRIDGE : TOWER BASE

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MOCKINGBIRD BRIDGE : TOWER ANCHOR HEAD

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TYPICAL SECTION

•Edge Girders & Floorbeams W12 Sections •Slab composite with floorbeams only • Edge Girders Designed Non-Composite •Lateral Loads taken in Vierendeel Action • Weak Axis Bending of the Beam •Slab Diaphragm Action

FRAMING DETAIL

•Floorbeam to Girder – Full Moment Connections Throughout •Temporary props to be designed by others

MOCKINGBIRD BRIDGE : SUPERSTRUCTURE

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Girder Splice (Typ.)

•Edge Girders & Floorbeams •12” WF Sections FRAMING PLAN

• W12x106 Girders

• W12 x 53 Floorbm •Horizontal curvature: Edge Girders rolled “the easy way” R = 1491ft and R = 1509ft FRAMING PLAN Girder Splice

Temporary Prop

•No vertical camber required •End Cuts & Splice Geometry to Accommodate Profile

•Variable Depth Haunch @ Floorbeams

ELEVATION MOCKINGBIRD BRIDGE : SUPERSTRUCTURE FRAMING

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FIXED DISK BEARING

Bumper

MOCKINGBIRD BRIDGE : TOWER BUMPER DETAILS

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•Anchorage Fin Plate Weldment •Bolted Connection At Floorbeam Locations •Combined Floorbeam Connection Plate Cable Anchorage

MOCKINGBIRD BRIDGE : CABLE ANCHORAGE CONNECTIONS

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• 36 Precast Panels – 15’-8” wide by 11’-2” + hairpins •Conventional Reinforcement (No Post-tensioning) •Composite with Floor Beams •Transverse Cast in Place Closure Pours

MOCKINGBIRD BRIDGE : DECK CONSTRUCTION – PRECAST PANELS

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MOCKINGBIRD BRIDGE : BRIDGE RAILING

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Lighted Rail MOCKINGBIRD BRIDGE : GUARDRAIL DETAILS

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• Install Micropiles • Place Foundations • Pre-stress tension piles

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Erect temporary props • Erect tower steel • Install back-stays

• Inject Self-Consolidating Concrete • Adjust back-stays & survey towers

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Single-pick superstructure erection • Girder splices adjacent to props • Longest section 62’-6” • Minimize roadway closures • Identical Operation to falsework erection MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Steel superstructure supported by temporary props

• Install Cables to a predetermined length

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Cable installation with a come-along

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Continue cable installation

• Steel framing is gradually lifted off the temporary props

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Install stay cables at Tower 4

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Install stay cables at Tower 3

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Install final cables • Survey steel profile & tower alignment

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Place precast panels • Survey steel profile & tower alignment • Adjust cable forces

• Place panel closure pours

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Remove temporary props • Install bridge railing • Install lighting & utilities

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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• Place Pour-back at back-stay anchor plates • Install abutment back-walls • Install compression seals

MOCKINGBIRD BRIDGE : SUGGESTED CONSTRUCTION STAGING

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CONDITION SURVEYS (SP599Y) • Tunnels, Tunnel Portal, Retaining Walls

Note: Images are not from DART tunnels.

• Limits – refer to B-99 to B-101

• Pre-construction, postconstruction, intermediate condition survey requirements. • Relevant Codes & Standards •Anticipated equipment • Inspector qualifications

MOCKINGBIRD BRIDGE : CONDITION SURVEYS

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CONDITION SURVEYS (SP599Y) • Tunnels, Tunnel Portal, Retaining Walls • Limits

• Pre-construction, postconstruction, intermediate condition survey requirements. • Relevant Codes & Standards •Anticipated equipment • Inspector qualifications

MOCKINGBIRD BRIDGE : CONDITION SURVEYS

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INSTRUMENTATION & MONITORING (SP599X) • Instruments: types, locations, purpose •Accessibility issues • Baseline readings • Alert & limiting levels

• Monitoring frequency • Reporting

MOCKINGBIRD BRIDGE : INSTRUMENTATION AND MONITORING

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DART Interface • DART Contact: • DART input to design process • DART approval of Instrumentation & Monitoring Work Plan • Night time access (during non-service hours) only.

• DART requirements (e.g., security clearances, safety training, etc.) covered in upcoming addendum.

MOCKINGBIRD BRIDGE : DART INTERFACE

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Contractor Qualifications • Submit with bids: – Complex Bridge (2 in past 5 years)

– Cable Stays & Connections – Micropiles & Ground Anchors (5 in 5 years) – Steel Fabricator (AISC certified shop, AWS D1.5 certified welders) – Tunnel Lead Inspector (10 years experience)

MOCKINGBIRD BRIDGE

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Forthcoming Addendum • Qualifications Submittal with Bid • Erection Engineering – By Contractor

• DART Special Provisions – Coordination – Safety Training – Security Clearance

MOCKINGBIRD BRIDGE

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Forthcoming Addendum • Qualifications Submittal with Bid

Questions

• Erection Engineering – By Contractor

• DART Special Provisions – Coordination – Safety Training – Security Clearance

MOCKINGBIRD BRIDGE

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