accelerated bridge construction

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ABC By 2010 1 UTAH Department of Transportation ACCELERATED BRIDGE CONSTRUCTION BY 2010 How have we done? ACCELERATED BRIDGE CONSTRUCTION BY 2010 How have we done? Fred Doehring Fred Doehring UDOT Structures UDOT Structures ABC by 2010 UDOT goals – Accelerated Bridge Construction Standard practice by 2010 What was needed? – Methods of construction – Standard details – Commitment to a program Vision for “Family” of ABC Methods Precast Concrete Elements Prefabricated Prefabricated Components Components Modular Construction Large Prefab. Large Prefab. Components Components Structure Placement Methods SPMT SPMT Sliding Sliding Accelerated Bridge Construction Accelerated Geotech Work Geofoam Geofoam Fast Track Contracting CMGC CMGC Design/Build Design/Build ABC Phase 1 Early implementation of ABC – Scanning Tours Looked at what other states were doing – Workshops held Brought all stakeholders together Identified what was needed Prioritized needs Looked at several specific pilot projects ABC Phase 1 Results of Phase 1 work – Several key standards were developed Precast Full Depth Deck Panels Manual on Self Propelled Modular Transporters (SPMT’s) Development of specifications and manuals for each Several pilot projects initiated and built ABC Methods Used Precast Deck Panels Voided Slabs Precast Substructures – Abutments and Bent Caps Precast Superstructures – Crane, Sliding, and SPMT

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Accelerated Bridge Construction 2010, a presentation on advanced bridge building techniques by the Utah Department of Transportation

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  • ABC By 2010 UTAH ABC by 2010 Department of Transportation ACCELERATED UDOT goals BRIDGE CONSTRUCTION BY 2010 Accelerated Bridge Construction Standard practice by 2010 How have we done? What was needed? Fred Doehring Methods of construction UDOT Structures Standard details Commitment to a program Vision for Family of ABC Methods ABC Phase 1 Early implementation of ABC Accelerated Scanning Tours Bridge Construction Looked at what other states were doing Workshops held Brought all stakeholders together Precast Modular Structure Accelerated Fast Track Concrete Elements Construction Large Prefab. Placement Methods Geotech Work Contracting CMGC Identified what was needed Components Design/Build Prefabricated Components SPMT Sliding Geofoam Prioritized needs Looked at several specific pilot projects ABC Phase 1 ABC Methods Used Results of Phase 1 work Several key standards were Precast Deck Panels developed Voided Slabs Precast Full Depth Deck Panels Precast Substructures Manual on Self Propelled Modular Transporters (SPMTs) Abutments and Bent Caps Development of specifications Precast Superstructures and manuals for each Crane, Sliding, and SPMT Several pilot projects initiated and built 1
  • ABC By 2010 Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth 2
  • ABC By 2010 Precast Deck Panels - Full Depth Precast Deck Panels - Full Depth Voided Slabs Voided Slabs Precast Substructure Precast Substructure 3
  • ABC By 2010 Precast Substructure Precast Substructure Precast Superstructure - Crane Precast Superstructure - Crane Precast Superstructure - Sliding Precast Superstructure - Sliding 4
  • ABC By 2010 Precast Superstructure - SPMT Precast Superstructure - SPMT Precast Superstructure - SPMT Precast Superstructure - SPMT Precast Superstructure - SPMT Precast Superstructure - SPMT 5
  • ABC By 2010 Precast Superstructure - SPMT Precast Superstructure - SPMT UTAH ABC Phase 2 Department of Transportation Standardized the remainder of prefabricated ACCELERATED element types BRIDGE CONSTRUCTION BY 2010 Developed details for: Precast substructures Piers, Abutments, walls, culverts Where are we going? Precast Approach slabs Precast Girders Pre-tensioned Bulb Tees Michael Culmo Post-Tensioned Bulb Tees CME Associates, Inc. Deck Bulb Tees Developed Specifications and Manuals Workshops were held for industry input Connections with Grouted Splice Couplers ABC Phase 2 Emulates a reinforcing steel lap splice Other work completed in Phase 2 Used in precast parking garages and Reviewed computer monitoring data from first stadiums and bridges round of SPMT bridge moves New seismic research coming Refined Phase 1 work based on lessons learned in construction Deck Panel standards and specifications SPMT Manuals 6
  • ABC By 2010 Connections with Grouted Splice Couplers Typical Connection Details Installation video on Youtube Search Georgia Bridge Pier Column or wall panel to footing connection Typical Connection Details Current Typical Details Single column hammerhead Column to cap connection Two column bent Three column bent Current Typical Details Current Typical Details Columns Footings Rectangular are possible, Full Precast but not preferred Round columns are difficult For smaller footings to precast Must be cast vertically Use Hexagonal or octagonal shape Can be cast on side (one side open) Shim and grout under footing through ports in footing 7
  • ABC By 2010 Current Typical Details Current Typical Details Footings Pile supported Partial Precast footings For larger footings Use corrugated Precast designed to support DL of bridge pipe forms CIP extensions designed for Used for integral other loads abutment stems Precast Portion also CIP Extension Shim and grout under footing through ports in footing Pretensioned Bulb Tee Girders Pretensioned Deck Bulb Tee Girders Post-tensioned Bulb Tee Girders Integral Abutment Details 8
  • ABC By 2010 Cantilever Abutments and Walls Stage 1 Use corrugated pipes in stems to reduce weight To be filled with concrete in the field Reduces the number of pieces 1. Drive Piles Stage 2 Stage 3 1. Install pier wall panels. (day 4) 2. Connect to footing via grouted 1. Place footings over pile and set splice couplers (day 4) to grade and alignment (day 1) 3. Fill voids with concrete to within 2. Cast concrete in voids around 3 feet of top (day 5) piles (day 1) 4. Install rebar cage in top of voids 3. Cast concrete between footings extending 2 feet above (day 5) if required (day 2) 5. Joints between may be grouted or left dry Stage 4 Final Construction 1. Install pier cap, set to grade (day 6) 2. Pour concrete through ports to fill voids and make connection (day 7) 3. Install precast beam seats (day 7) 9
  • ABC By 2010 Box Culverts Tolerances Precast boxes, aprons, and walls Tolerance details developed for all critical elements Based on PCI Tolerance manual MNL-135-00 Tolerance Details Tolerance Details Splice couplers Columns Precast Full Depth Deck Panels Precast Full Depth Deck Panels First Generation Standards completed in Phase 2 Modifications Phase 1 UDOT ABC Program Use Longitudinal Post-Tensioning to Connect Panels AASHTO Code Recommendation More than 15 project built to date Better performance over time (no leakage through joints) Costs are coming down Use multi-strand PT systems Developed for slabs Welded plate details are not desirable More Flexible Time Allow blind pockets for shear stud connection Based on recent research Leakage issues at joints Allow skewed deck panels (up to 15 degrees) There is new technology in the market 10
  • ABC By 2010 Precast Full Depth Deck Panels Blind Pocket Project Texas DOT Recommended Post-tensioning System Multi-strand deck PT systems Developed specifically for decks (thin anchorage) Used by other states Recommend the use of less than maximum amount of PT allowed in the ducts (4-0.5 strand) UDOT Blind Pocket Details Schematic Construction Details 2 Span Bridge using UDOT Standards 11
  • ABC By 2010 Excavate and Install Piles Install Abutment Stem and Footings Typical 2 Span Bridge Typical 2 Span Bridge Install Pier Columns Install Pier Cap and Wingwalls Fill Voids in Abutment Stems Cast Footing Closure Pour Typical 2 Span Bridge Typical 2 Span Bridge Erect Girders Install Backwalls and Sleeper Slabs Typical 2 Span Bridge Typical 2 Span Bridge 12
  • ABC By 2010 Install Deck Panels and Approach Slabs Cast Deck and Approach Slab Closure Pours Typical 2 Span Bridge Typical 2 Span Bridge Construction Roadway Approaches Bridge Monitoring (TAC) Volunteer group of key stakeholders UDOT Design Consultants Contractors Industry Representatives Charged with review of data and recommendations for future SPMT bridge moves Used computer monitoring data from 2008 Typical 2 Span Bridge Bridge Monitoring (TAC) Bridge Monitoring (TAC) Data retrieved Temperature Strain Mostly strain data (deck, girders) Layouts were similar on each bridge Dynamic Strain Used to study the stresses within the bridge during: Lifting Moving Lifting Strain Placement Utah State University (USU) Brought in to analyze and disseminate the data With input from the TAC Typical Data 13
  • ABC By 2010 Bridge Monitoring (TAC) SPMT Manual Revisions Final Findings and Recommendations Build on knowledge gained in 2008 Lifting stresses are very significant Supporting the deck at the lift points eliminated most deck cracking No major changes Lift bridge closer to ends (0.2L or less) Lightweight concrete in the deck helps to reduce deck cracking, and Define roles of project participants overall lift weight Written to fit in with the UDOT Design Dynamic effects can be approximated by increasing dead load by 15% Network Starting and stopping of SPMTs Traversing bumps during the move 3d Analysis is needed to estimate lifting stresses if a flexible carrying beam is used Recommended future gaging locations SPMT Lifting Methods Lessons Learned Study of Performance of ABC Bridges Bridge Types Studied Full Depth Deck Panels with welded tie connections (6) Full Depth Deck Panels with Post-Tensioning (2) Precast Parapets integral with deck (5) SPMT Bridge Moves (9) Neg. DL moment on girder Neg. DL moment on Precast Abutments (2) May be a problem with composite section prestressed girders Significant deck cracking is Precast Piers (2) Light weight concrete could possible help Light weight concrete could Inspections took place in May, 2009 Little or no deck cracking help Deck is pre-compressed in final condition Lessons Learned Lessons Learned Project locations Purpose of the study Milepost 200 on Route 6 not shown Investigate the performance of each component type What is performing well and what is not Not intended to critique past designs Most of these bridges were designed prior to development of standards Many were designed as short term fixes prior to full replacement in the near future (10-25 years) Goal: Continuous Improvement of Quality 14
  • ABC By 2010 Lessons Learned Lessons Learned Welded Tie Connections Welded Tie Connections Joint Leakage is widespread Shear transfer is still working Composite connection is good Lessons Learned Lessons Learned Welded Tie Welded Tie Connections Connections Lessons Learned Lessons Learned Post Tensioned Connections Post Tensioned 3 span continuous bridge Connections No Joint Leakage Even in negative moment areas Underside of deck I-215 at 3900 South 15
  • ABC By 2010 Other Long Term Performance Information Project Information Curved structure (straight beams) I-84/Route 8 Interchange Waterbury, CT 6 Span bridge with continuous spans Single lane Prestressed transversely and post tensioned longitudinally Details similar to UDOT 42 Day construction No construction problems Built in 1991 After 18 years of service After 18 years of service Excellent condition Used membrane waterproofing and Asphalt Wearing surface No leakage through joints Another long term example project Lessons Learned Route 8 Viaduct, Seymour, CT Precast parapets integral with precast 2 Curved structures decks Over 50 spans (all simple spans) Most are good Prestressed and post tensioned Problem with panels cast with 2 parapets Weekend closures only No transverse adjustment during installation Old deck removed on Friday night New deck erected on Saturday morning Post tensioned on Saturday night Grouting on Sunday morning Open to traffic Sunday night Asphalt wearing surface with waterproofing membrane In service for 15 years Excellent condition 16
  • ABC By 2010 Lessons Learned Lessons Learned Precast Abutments Few have been built Horizontal joints (Lego bridges) None built to new standards yet There were significant fit-up problems on one bridge Can be resolved with appropriate casting tolerances Performing well Lessons Learned Lessons Learned Precast Piers Few have been built None built to new standards yet One is similar Construction went well Performing well Lessons Learned Lessons Learned SPMT Bridge Moves Deck cracking is common Exceptions: Bridges cast while supported at lift points Lightweight Concrete Deck Some leakage through cracks Performing well 17
  • ABC By 2010 Lessons Learned Lessons Learned Lessons Learned Lessons Learned Cast-in-place closure pours Some have significant shrinkage cracks Restraint of adjacent panels Some leakage through cracks Lessons Learned Lessons Learned Shear Connector Pockets Several have minor leakage around pockets (not all) Shrinkage of Grout Blind pockets should alleviate this 18
  • ABC By 2010 Lessons Learned Lessons Learned Recommendations Full Depth Deck Panels Eliminate welded tie detail Always use post-tensioning Use blind pocket detail for shear connectors New Standards address these recommendations Lessons Learned Lessons Learned Recommendations Recommendations Precast integral parapets Precast Abutments and Piers Do not use 2 per panel Use vertical joints in abutment stems and wall stems Use a longitudinal closure pour in deck to allow for Allows for easier fit-up in the field adjustment in the field No problems noted with pier construction Cast one or both in the field behind temp. barriers New Standards address these recommendations Lessons Learned Lessons Learned SPMT Moves Other general recommendations TAC Committee work verifies issues found in Overlays the field Consider thicker overlay with a quality Pick bridges closer to ends waterproofing membrane If possible, support girders at lift points during European and East Coast Systems deck casting CME recommendation, not UDOT policy Investigate the use of lightweight concrete to Closure Pours reduce deck and girder stresses Use a better high early strength concrete mix New SPMT Manual will address these Shrinkage compensating mixes recommendations NY State mix is being investigated 19
  • ABC By 2010 Where are we going? Where are we going? UDOT Themes Implementation of Phase 2 Standards Accelerate Delivery Training Design and Construction Designers Decrease MOT Construction Inspectors Reduce User Costs and impact to society Bridge Inspectors Encourage Innovation Bridge Maintenance Personnel Get a good price On-call technical support Where are we going? Where are we going? Manuals Continue to monitor progress Develop a Bridge Design Manual Annual inspection of ABC Bridges New SPMT design guide to be issued Address issues as they arise Lightweight Concrete Goal: SPMT Decks (minimize deck cracking) Continuous Improvement Substructure Elements (reduce shipping and handling costs) Questions? Testing data This presentation will be posted on the UDOT website Grouted Splice coupler @ end of column 20
  • ABC By 2010 Testing data Control Column w/o Grouted Splice Coupler 21