HBM-US 20 over Pecatonica

Description of Work

HBM Engineering Group, LLC performed routine field inspection in accordance with NBIS of the existing US 20 eastbound bridge over the Pecatonica River in Stephenson County. The Master Structure Report, Routine Inspection Report and the Special Feature Report were submitted with the recommended needed repairs to IDOT District 2. Contract plans, specifications, and cost estimates, (PS&E), were developed based on the repair recommendations. Estimated time of construction for the bridge rehabilitation and engineering support services such as steel shop drawing review were also included.

The existing bridge is an 11-span steel plate girders bridge with a 47’-2” wide reinforced concrete deck supporting two thru lanes and right and left shoulders of Eastbound US 20. (S.N. 089-0042) The bridge was showing signs of distress. Measurements were taken for needed structural bridge repairs such as deck repair, structural concrete repair, expansion joints replacement, sealing cracks, steel section losses, bearing repairs, paint distress and bridge approach and shoulder repair. A deck drainage study was performed and the existing deck drainage system was replaced with new floor drains and drainage scuppers. Shoreline migration near the piers was investigation and recommendations were submitted to District 2.

The design plans described and quantified some of the following work items: deck repair both partial and full-depth; removal of the existing deck drainage system and replacement with new floor drains and scuppers; scarifying ½” of the top of deck and adding 2 ¼” of bridge deck latex concrete overlay; replacement of expansion joints at the south and north abutments, piers 6 and 9; sealing the front face of parapets; structural steel repairs for steel members with section losses located under the expansion joints at the south and north abutments, pier 6 and pier 9 (the need for these repairs was determined after measuring section losses and performing structural analysis and load rating calculations for the critical members); clean and repaint outside face of fascia girders; repair clean and paint the existing bearings and clean and apply concrete sealer to bridge seats located under the expansion joins at the south and north abutments, piers 6 and pier 9; remove and replace cracked and settled shoulders and adjust shoulder inlets at the approaches to the north and south abutment; construct butt joint and HMA overlay of north and south approach pavement and shoulders; and restore pavement marking and pavement reflectors.

HBM provided for Traffic Control and Protection plans for staged construction. A three stage traffic control plan utilizing temporary concrete barrier was used to maintain at least one lane of traffic during the bridge rehabilitation work.