Repair History

The Gurley Overpass was constructed in 1982 to create a separated grade crossing of the Burlington Northern Railroad tracks and Highway 14-16.  Minimal maintenance and repair was done until 1999, when the expansion device at mid-span was replaced and the deck was resurfaced.  In 2010, a project was undertaken to replace the bearing devices on the north half of the overpass, to replace the center expansion device with an updated design, to stabilize the north bridge abutment, and to perform significant repairs to the deck.

A maintenance plan was proposed at the close of the 2010 project to extend the life of the structure and to prolong the period of time between significant repairs.  In 2013 we sealed the deck with a healer sealer product to reduce water infiltration, and in 2015 we performed structural repairs to pier 5 and the north abutment which had been caused by leakage through the old expansion device and the joint at the north abutment.

Barrier Repair

This scope of work addresses the next maintenance goal for the overpass.  The proposed scope of work is designed to restore the barriers and slow degradation, extending the life of the concrete barriers.

The existing condition and distress to the barriers was mapped and documented.  Several scenarios were considered ranging from current recommended method to full replacement of the barrier.  Also considered was the anticipated useful lifespan of the existing bridge deck, on which the barriers are supported, as compared to the anticipated useful lifespan of the various repair or replacement.  The selected repair is anticipated to have a comparable lifespan as the existing deck

Base Bid

The selected repair method will remove unsound concrete, patch the concrete, apply a mortar surface coating, and apply a water repellent to the completed surface.   This type of repair will allow for future spot repairs to be blended into the existing surfacing.  The water repellent coating will be reapplied annually.

Alternative 1  - Epoxy Crack Injection

There are many vertical cracks in the barriers.  It is believed that these cracks are largely caused by the expansion and contraction of the deck as well as the flexure of the deck when loaded.   Alternative 1 is the injection of an epoxy repair material into selected cracks in the barriers.  Not all cracks will receive the epoxy repair material.  It is believed that many of the cracks would likely reform after the repairs are completed.

Alternative 2  Epoxy Deck Overlay

This alternative scope would provide for a high friction epoxy and aggregate overlay of the existing bridge deck.  This overlay would serve to protect the existing silica fume deck surface from damaging moisture and road salt, serve a wear surface, and add a higher friction surface to the overpass.  Although it is not possible to accurately predict, the epoxy overlay will likely extend the useful life of the deck.

Unfortunately, a spall in the existing deck surface has occurred during the bidding period of this project.  Any spalls or de-laminated areas in the deck will have to be repaired prior to the epoxy overlay for the overlay to perform properly.  As the extent of the deck repair has not been fully investigated and quantified, the change in cost for the deck preparation and the impact on the schedule is not known.  There is a risk the deck repairs and overlay could not be completed before weather conditions cause a stop work for the season.

It is recommended that a full evaluation of the deck be performed, a more well defined scope be developed, and the epoxy deck overlay be re-bid next spring with a more accurate scope of deck repair and schedule to complete the work.

Bidding Results

Two bids were received and read aloud by the City of Gillette Purchasing Department at 2:30 PM on June 29, 2017. 

The bids results are as follows:

Two minor mathematical errors were discovered in Van Ewing Construction's bid.  The total error was $.64 between two bid items and is considered to be insignificant.

Van Ewing's Base Bid was 42% of the Engineer's Estimate and 54% of the nearest competitive bid provided by S&S Builders.  Van Ewing's Alternate 1 bid was 30% of the Engineer's Estimate and 58% of the nearest competitive bid provided by S&S Builders.  Van Ewing's Alternate 2 bid was less than 1% less than the Engineer's Estimate and 21% greater than the nearest competitive bid submitted by S&S Builders.

Van Ewing Construction has been contacted and informed that their bid was significantly lower than the nearest competitive bid as well as the engineer's estimate.  Van Ewing indicated that they believe that nothing was left out of their bid.

The City and our consultant Structural Dynamics, met with Van Ewing on July 7, 2017 and discussed the bid.  Van Ewing believes they have the resources and equipment to compete the work with in the time frame allowed.

Van Ewing Construction, Inc. submitted the lowest bid for both the Base Bid and Alternate 1.  Based on the our consultants bid analysis and conversations with Van Ewing as discussed above, it is recommended to award the Base Bid and Alternate 1.

The Contractor will have 35 working days plus five (5) for Alternate #1 for a total of 40 working days to reach substantial completion.  An additional five (5) working days will be allowed after substantial completion is attained to reach final completion.  Regardless of the number of working days, all work must be complete by October 6, 2017.  Work days will be from 6 AM to 5 PM.  During these hours the overpass will be closed to traffic.  The overpass will be fully open to traffic outside of these hours.

The funding for this project ($720,000) has been allocated from the 1% Optional Sales Tax Account 201-10-05-419-70-47404.