R2009-50 AUTHORIZING AGREEMENT WITH URS CORPORATION

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� b a Engineering & Infrastructure Memorandum NO. 2009-24 DATE: Apri113, 2009 TO: Honorable Mayor Carrigan and City Council �> FROM: Ryan P. McCrady, City Manager ��C-� `� Richard G. Marley, P.E., Director for Engineering& Infrastructure SUBJECT: Agreement with URS Corporallon for Preliminary Design of the South Shores Bridge over the Sand Creek Arm of Lake Decatur SUMMARY RECOMMENDATION: It is recommended by staffthat the City Council approve the attached Resolution authorizing an Agreement with URS Corporation for the preliminary design of the South Shores Bridge over the Sand Creek Arm of Lake Decatur, and the Mayor to sign and the City Clerk to attest. The expenditure for these services is not to exceed $77,500. BACKGROUND: Prior Council Action • August 2, 2004—Council approved Resolution R2004-115 authorizing an Agreement with Homer L. Chastain&Associates (Chastain) to inspect five precast concrete deck bridges, including South Shores/ Sand Creek, for a fee not to exceed $7,965. Background The South Shores-Sandcreek Bridge was originally built in 1909. A new superstructure was placed on the old abutments in 1965. The foundation and abutments are 100 yeazs old and the superstructure is 44 years old. In 2004 The Illinois Department of Transportation(IDOT)notified governmental entities throughout the State that problems had been detected in precast deck beam bridges. These bridges are strengthened with cables that have been placed under tension within the beams in order to provide support for the structure. It had been found in other areas of the State that the tensioned cables within these bridges can deteriorate to the point of failure while showing few outward signs or damage. At the time, IDOT advised an in-depth inspection of these bridges. Chastain's 2004 review indicated a need to replace the bridge deck at a future date. Inspections carried out by City staff and various consulting engineers since 2004 have determined that the outside beams of this bridge have moved with respect to the rest of the bridge. In August of 2006, the Illinois Department of Transportation directed the City to place a weight restriction on the bridge and to perform regular follow-up inspections to monitor the outside beams of the bridge. Since the damaged beams are not in the wheel path, the bridge is safe for normal traffic; however, the bridge deck needs to be replaced in the near term before damage progresses and more strict traffic restrictions are imposed. Page � 1