ACTT Workshop: New York
Tappan Zee Bridge Deck Replacement
Chapter 3: Skill Set Recommendations
3.1. Construction/Innovative Contracting
The construction/innovative contracting skill set focused on possible contract and construction innovations and made the following recommendations:
Suggested Contract Innovations
- Streamline the contracting process.
- Consider electronic shop drawings and, where applicable, accept intent drawings.
- Reuse deck sections from the temporary bridge to capture value.
- Use incentives/disincentives.
- Pre-purchase deck sections.
- Pre-qualify contractors.
- Schedule a mandatory pre-bid orientation conference.
- Pre-qualify suppliers.
- Use a modified issue resolution model.
- Consider partnering.
Details and Methods
- Is post-tensioning a given? Could eliminate it to expedite pre-casting and erection.
- Is match casting necessary? Could eliminate it to simplify pre-casting.
- Increase length of spans to 100 feet-plus to expedite erection.
- Use lightweight concrete deck.
- Note that the PLA (Project Labor Agreement) is expiring.
- Consider staging areas.
- Assemble as much as possible off-site, including the barrier.
- Encourage water erection option.
- Ship the structure in pieces and assemble it at the staging area.
- Consider the "tried and true" - design team's option two.
- Consider the "no lane closure" option. Construct a temporary four-lane detour bridge on the north side of the causeway section. Reroute the west shore to bent 130.
- Bid both options as alternatives.
Pre-purchasing of Deck Section (Full or Partial)
- Eliminates contractor mark-up and shifts responsibility to the owner.
- Saves time and improves public perception.
- Complicates liability issues.
- Jump-starts the process.
- Requires the owner to do more coordination and planning.
- Raises concerns with the sections that are not cookie-cutter, i.e., the curved causeway.
- Consider the 250-foot truss sections.
- Consider temporary barrier storage and set-up.
- Works if variables are minimized.
- Consider paid incentives per panel.
- Look at 1997: fines if not out of the road; $1,000 per minute per lane after 6:00 a.m.
Temporary Four-Lane Detour Bridge: an Out-of-the-Box Solution
- Consider reusable deck sections, or make them part of the permanent bridge truss spans.
- Would eliminate six- to eight-hour work limitation.
- Would save a lot of money for the users.
- Consider the length of the temporary bridge - could be from 15 bents to as many as 130 bents.
- Consider permitting issues.
- Consider 24/7 work.
- Note that revenue would not be lost - a benefit of keeping traffic flowing.
- Address liability issues, i.e., who would own the structure.
- Consider steel grid deck versus orthotropic.
- Need to address the lead time problem.
- Consider seasonal issues and tidal variations.
- Use the temporary bridge deck on truss.
- Consider pre-engineered ramps.
- Check on the feasibility of a semi-floating bridge, and determine if the temporary bridge needs to be straight.
- Decide between concrete boxes or fabricated steel buoyant supports.
- Do a cost analysis.
Tried & True: Option Two
- Recommend water access: it appears to be best for the causeway and for traffic. (Could also use larger panels with water erection.)
- Pre-purchase deck sections.
- Look at diversionary revenue loss.
- Consider the fiber optic concern: it would need temporary support.
Comparison of Options
- Do engineering cost estimates.
- Bid both options.
- Establish and publish criteria for the evaluation and selection of the low bidder for each option.
- Consider impacts such as reduced lighting, noise, etc.
- Promote public good will.
- Hold periodic information meetings for the public and meetings with stakeholders as needed; this worked well on Interchange 8.
- Remember that this is a big maintenance project; need to keep project-limited scope.
- Start the meetings at construction, not during design.
- Hire a consulting firm to handle public information.
The structures team began by identifying key issues, namely concerns with the deck and substructure noted earlier in the report. They suggested that construction be scheduled from 8 p.m. to 6 a.m. weekdays to minimize traffic impacts.
Use prefabricated elements:
- Precast slabs and stringers off-site.
- Minimize concrete pours and grouting on-site.
- Use galvanized steel.
- Use barges/river transportation where possible.
- Consider expanding the scope to cover all lanes: future replacement of the center girders would be difficult.
- Consider using barges:
- Would limit construction traffic on the bridge.
- Is feasible up to the deck truss.
- Discuss staging areas.
- Use self-propelled modular transporters (SPMTs).
- Use large cranes for high level work.
- Alternative 1 - no build.
- Would require major long-term maintenance.
- Agree with the design report that this is not a viable option.
- Alternative 2 as proposed - comments on details presented by the Thruway.
- Believe the design is feasible: it's been executed successfully.
- Believe that match cast (differential camber) may be difficult to execute.
- Recommend a grouted shear key.
- Eliminate transverse post tensioning.
- Use structural simple spans with jointless design.
- Consider incorporating small closure pour.
- Recommend elastomeric bearings with provisions for vertical adjustments.
- Alternative 2 - causeway: one span, one piece (50 feet x 40 feet).
- Would need to ship pieces via barge or bring them in by road and assemble them on-site.
- Would require specialized equipment (SPMTs or barge-mounted cranes).
- Most likely a faster option.
- Would not require longitudinal joints.
- Could utilize uniform beam spacing.
- Could utilize barges similar to single span causeway approach.
- May be faster than single span approach.
- Would require fewer bearings.
- Recommend grade 50 steel - rolled beams.
- Need to understand that dead load distribution/reactions is a concern.
- Alternative 2 - deck truss - alternate framing issues.
- Need continuous stringers.
- Add joints to facilitate construction (optional to bidder).
- Confirm that existing deck is non-composite.
- Could possibly replace deck with exodermic panels.
- Provide a 16-hour lane closure (four lanes open) so that a 250-foot section is feasible.
- Could be constructed in a 10-hour window
- Alternative 2 - through truss - construction constraints.
- Would need to complete work within the existing truss.
- Overhead clearance limits size of pieces (installation equipment).
- Might need to ship pieces via roadway. There are width limitations.
- Could ship pieces by barge and lift them to the roadway on the approaches.
- Could possibly do an exodermic deck replacement.
- Alternative 3 - deck replacement - entire bridge.
- Would prove difficult with a composite deck. (Removal would be hampered by shear spirals.)
- Probably wouldn't work within the available time frame.
- Need to factor in steel repairs, which could be costly.
- Does not address the fascia beam issue.
- Out of the box.
- New causeway: build a new permanent parallel causeway adjacent to the trestle structure.
- Would be no significant traffic impacts.
- Could be less expensive. Repetitive work would take place away from traffic.
- Might face additional environmental issues, which could require additional permits and more time prior to contract letting.
- May be faster construction.
- Has the potential to incorporate into future bridge plans.
- Temporary bridge over: construct a temporary bridge above the existing bridge (six to eight feet above existing deck).
- Would allow all work to take place UNDER traffic.
- Would require minimal traffic control.
- Could schedule work 24 hours a day.
- Faces potential issues with the existing geometry (horizontal curve, grades).
- Note potential issues with the load capacity of the existing bridge.
- Temporary parallel structure(s): build temporary bridge(s) alongside the existing bridge.
- Would probably require piles to support the bridge(s).
- Faces potential highway geometry concerns.
- Would need to address construction timeframe.
- Would need to work with Coast Guard (for permitting, etc.).
- Appears to be a costly option.
- Lightweight structural overlay: install a lightweight thin overlay over the existing deck.
- Would utilize a thin filled grid placed on top of the existing deck.
- Would be the least costly of all the options.
- Does not address the fascia girder.
- Does not address the existing fatigue of the stringers.
- Eliminates the potential for deck punch-outs.
- Does not address any of the safety aspects that may be required.
- Innovative materials: use lightweight materials for the deck to add shoulder width on the trestles.
- Use lightweight concrete.
- Consider an FRP deck on stringers.
- Consider an orthotropic deck.
- Precast concrete superstructure: consider a 50-foot x 40-foot two-way slab with edge beams.
- Might require lightweight concrete.
- Could be pre-stressed.
- Would be similar to a precast slab on stringers.
- Was used successfully on the Robert Moses Causeway in Long Island.
The traffic/safety/ITS team identified six main items for discussion: E-ZPass (electronic toll collection system) applications; operations; information dissemination; volume management techniques; work zone traffic control; and worker safety:
- Use pre-scheduled crossings.
- Utilize congestion pricing.
- Consider only E-ZPass customers.
- Accelerate TRANSMIT program.
- Add readers.
- Obtain origin/destination information.
- Do a regional origin/destination survey.
- Implement super incident management program.
- Increase speed enforcement.
- Enhance bridge incident detection.
- Analyze and respond to real-time traffic requirements on bridge.
- Consider AM/FM radio preemption.
- Coordinate regional ITS messages.
- Accelerate regional VMS program.
- Coordinate with regional industries.
- Coordinate with emergency responders.
- Foster intergovernmental relationships.
- Develop internal action plan.
Volume Management Techniques
- Promote a mode shift.
- Promote regional diversions.
- Close exits 9 and 10.
- Prohibit nighttime trucks.
Work Zone Traffic Control
- Consider reduced lane widths.
- Create emergency pullouts/crash investigation sites.
- Provide for late lane merge.
- Have a memorandum of understanding (MOU) with State police.
- Provide contractor incentives.
- Consider dynamic lane use.
- Create a worker safety plan.
3.4. Public Relations
The public relations team defined an overall strategy, a media strategy, a stakeholder strategy, a corporate/commercial strategy and a public strategy:
- Provide internal coordination/communication.
- Detail the problem; create an information package (video); hire an expert/consultant.
- Have dedicated staff for outreach before, during and after construction.
- Acknowledge other studies/work in corridor.
- Have a contingency plan.
- Have the executive director meet with elected officials, chambers of commerce, stakeholders, etc.
- Develop an animated press kit.
- Attend editorial board meetings, TV station meetings, etc.
- Partner with traffic reporters.
- Give tours and presentations.
- Have follow up meetings.
- Use newspaper inserts.
- Coordinate a marketing startup/kickoff. Consider placing promotional spots.
- Create a dedicated web site with real-time data
- Have executive director talk directly to groups.
- Utilize a simple video.
- Utilize the speakers bureau (Public Relations).
- Research major carriers.
- Target or partner with MetroPool. (Major employers commute.)
- Partner with truck associations.
- Target major shippers, carriers and distribution centers.
- Create publications for the above target audiences.
- Provide timely and accurate information.
- Use fun, catchy and succinct "kazoos."
- Create E-ZPass mailings.
- Provide coupons for coffee.
- Coordinate Department of Motor Vehicles (DMV) mailings.
- Use Highway Advisory Radio, or HAR.
- Set up informational booths at rest areas.
- Consider toll adjustments/value pricing.
- Promote mass transit.
- Utilize billboards.
- Promote information through the schools.
- Define the purpose, and allow input.
- Handle locally.