Presentation on theme: "2013 Northcentral Region Construction Conference"— Presentation transcript:
1 2013 Northcentral Region Construction Conference WisDOT - Bureau of StructuresBrandan Burger & Dave Kiekbusch
2 Contact BOS – When & Why?Anything “structural” – change in loading, structural capacity, pile locationsIf in doubt, call us!See StructuresContacts HandoutRemind Contractor to go thru Construction Staff for answers
6 Shop Inspection Prestressed Concrete Girders Plant has one Quality Verification (QV) inspectorWeekly plant - QV reportsQV reports with girder acceptance recommendations are sent to region materials staff and forwarded to project personnel.Issues from the fabrication plant should NOT be re-visited at the job site. Final approval is made by project engineer at job site - any shipping or erection damage.Managed by Bureau of Technical ServicesEach plant has one Quality Verification (QV) inspector who is a consultant under contract to WisDOT.Approval at plant is weekly via QV inspection reports. QV reports with girder acceptance recommendations are sent to region materials staff and forwarded to project personnel.Issues from the fabrication plant should not be re-visited at the job site. Final approval is made by project engineers when girders are received at job site, which accounts for any shipping or erection damage.
7 Prestressed Girder Sweep Initial sweep is criticalFabricator’s responsibilityMeasured at the plantLong term sweep only a concern IF intermediate diaphragms don’t fit.Initial sweep is critical, is under the control of the fabricator, and is the fabricator’s responsibility.Measurements should be made just after form stripping and strand release in a “plant controlled” environment (no influence from temperature).If measured on bed, girder should be lifted and reset to free the ends.Measure sweep at the web mid-point utilizing a cotton or nylon string tied to the girder ends with sufficient tension and a conventional tape measure or ruler.
8 Exterior Girder Rotation Mostly occurs w/ steel & wide flange (>4’) prestressed girdersContractor’s responsibilityStrapping top flanges & bracing bottom flangesNO welding to top flange of steel girders or prestressed girder rebar!
16 Ancillary StructuresOverhead sign supports, sign bridges, traffic signal monotubes, high mast lighting polesContractor’s responsibilityAnchor bolt tensioning: DT each structureSubmit to the engineer - permanent project recordsEngineer’s responsibilityContact region traffic or maintenance - set up inspection as soon as each structure is completeOverhead sign supports, sign bridges, traffic signal monotubes, high mast lighting polesContractor must complete anchor bolt tensioning form DT2321 for each structure, submit to the engineer for inclusion in the permanent project records.Engineer should contact region traffic or maintenance individual responsible for setting up inspections as soon as each structure is complete
17 Ancillary Structures FOUNDATIONS: Too Low/Buried Too Low/Buried Removal of Excess FormworkShaft/Bar Cage Not Plumb or CenteredMissing Rodent ScreenFOUNDATIONS:Too Low/BuriedRemoval of Excess FormworkShaft/Bar Cage Not PlumbMissing Rodent Screen
18 Ancillary Structures ANCHOR BOLTS: Use of Lock Washer Out of PlumbLeveling NutsImproper TensioningANCHOR BOLTS:Use of Lock WasherOut of PlumbLeveling NutsImproper Tensioning
19 Ancillary Structures Bolted Connections: Missing Bolts on Truss Loose Bolts on SplicePrepped Splice PlatesFOUNDATIONS:Missing Bolts on Truss – All bolts must be installed on the ground before uplift up to the towersLoose Bolts on Splice – 3 out of 8 bolts not tighteningPrepped Splice Plates – Last photo shows dirt in between the splice plate. The plates should be clean and free of dirt
20 Ancillary Structures Bolted Connections: Faying Surface Gap Use of Lock WasherIncorrect Bolt Size/LengthBolted Connections:Faying Surface Gap – Friction Connection place oversized washer or filler plate in gapUse of Lock Washer – Shown harden Flat washer is O.K.Incorrect Bolt Size/Length
21 Ancillary Structures Sign Connections: Approved Hardware Oversized and slotted holeOver TensioningBlank Signs and coverBolted Connections:Approved Hardware – Photos 1 & 3 show inappropriate hardwaresOversized and Slotted Hole – Not allowedOver Tensioning - last photo shows cracked aluminum casting with over tensioning. Also shown uncoated bolts & NutBlank Signs and Cover – Blank signs must be used per plan notes when permanent sign is not available. Permanent signs should be covered when they are not in use.
22 Reinforcement 505.3.4 Placing and Fastening Plastic chairs – support bottom mat of rebarContinuous chairs – support top mat of rebar off bottom matNOT ALLOWED – individual plastic chairs to support top mat of rebarReminder: Hardware incorporated in deck must be galvanized, epoxy coated, stainless steel, etc.Welding is not permitted on epoxy steel.Placing and FasteningThe contractor may use recycled plastic supports for a bottom layer of steel reinforcement which in turn supports upper layers on continuous bar chairs; but do not use individual plastic chairs to directly support upper layers.Reminder: Hardware incorporated in deck must be galvanized, epoxy coated, stainless steel, etc.Welding is not permitted on epoxy steel.
25 Driven PilesNew Section 550: similar to STSP used for the last few years.Modified Gates – Required Driving ResistanceSpecification Covers:Steel, Cast in Place & Precast Concrete PilesPile PointsProviding test pilesDriving pilesDetermining required driving resistancePreboringPile redrivingNew Section 550: piling specifications that use a modified Gates formula to determine the required driving resistanceDescribes providing steel piles, cast in place concrete piles, and precast concrete piles; providing test piles; driving piles; determining required driving resistance; describes preboring or redriving.
26 Pile SplicesWeld splices conforming to the AWS D1.1/D1.1M Structural Welding Code-Steel.
27 Pile SplicesContractor certifies the quality of field welds as follows:Designate who inspects welding.Must be an AWS certified welding inspector (CWI) or a department-approved individual.Evaluate field welding at suitable intervals.Complete DT2320 for each structureSubmit form to the engineer - permanent project record.Certify the quality of field welds as follows:1. Designate who will visually inspect the contractor’s welding. Must be an AWS certified welding inspector (CWI) or a department-approved individual.2. Designated inspector must evaluate the field welding at suitable intervals.3. Designated inspector must complete department form DT2320 for each structure and submit the form to the engineer for inclusion in the permanent project record.
28 Pile SplicesIf piles drive longer than plan length, pay for field spliceCurrent policy: Splices paid as equivalent to the contract price for:HP piles = 9 feet per pile splicedOther piles = 6 feet per pile splicedONE payment per pile.Possible revision for 2014Additional payment under the Pile Splices administrative item for piles spliced in the field if the required driving resistance cannot be achieved in the length the plans show.Pay an amount equivalent to the contract price for 9 feet of piling for each HP pile spliced and for 6 feet of piling for each pile for other pile types. ONE payment per pile.Possible revision for 2014.
29 Painting Exposed Piling Section Painting:See the department’s approved product list “Paint Systems for Exposed Piling”
30 Temporary StructuresInspect temporary structures before opening to trafficConform to NBIS & department’s structure inspection manualGuidance in CMM: Chapter 5 StructuresContractor’s ResponsibilityIncluded in ASP 6Submit DT2007 to the engineer & BOS Maintenance SectionInspector must be department-certified active team leaderList online – see CMMIncluded in ASP 6Inspect temporary structures conforming to the National Bridge Inspection Standards and the department’s structure inspection manual before opening to traffic.Submit inspection reports on department form DT2007 to the engineer and electronic copies to the department's bureau of structures maintenance section.Ensure that a department-certified active team leader, listed online in the department's highway structures information system (HSIS), performs the inspections.Construction and Materials Manual: Chapter 5 – Structures, Section 65 – Temporary Structures
31 Bridge Approaches New Structural Approach Slabs US Highways & Interstates
32 Accelerated Bridge Construction Every Day Counts – FHWA InitiativeBridge Manual – ABC chapterCompleted WisDOT projects: Precast deck panels, abutments & pier caps; Inverted T girders; Superstructure lateral slides; Geosynthetic reinforced soil (GRS) abutments
33 Accelerated Bridge Construction Upcoming WisDOT projects: Self-Propelled Modular Transporter (SPMT), precast columns and pier cap, precast inverted TWisDOT continues to look for projects where ABC provides clear benefits.
34 Conclusion Call us with Questions We look forward to another great year of bridge construction!