Cedar Rapids Ionwave #3318551-01 Addendum 7

8th Avenue Bridge Replacement, Floodwalls, and Cedar River Civil Improvements

The City of Cedar Rapids Public Works Department is seeking bids for a major bridge replacement and flood-control project over the Cedar River. - Buyer: City of Cedar Rapids, Iowa — Public Works Department. - Scope: Demolish the existing 8th Avenue Bridge and construct a cable-stayed replacement bridge, floodwalls, approach roads, traffic improvements, sidewalks and trails, utility and lighting improvements, and mechanically stabilized earth (MSE) walls with foundation improvements. - OEM and named vendors: Ameristar is identified as the basis of design for DS22 anti-ram bollards at the guard shack. Stanley Consultants prepared the MSE wall stability calculation. No manufacturer is specified for the stay-cable system or other listed materials. - Bollards: 6 removable anti-ram bollards for the trail; the quantity of guard-shack bollards is not specified. The guard-shack basis of design is Ameristar DS22. - Additional bid quantities include 15,221 SY of 6-inch modified subbase; 1,471 SY of 8-inch shared-use-path concrete; 3,526 SY of 6-inch sidewalk concrete; 15,558 of sod; 12,981 LF each of 12-inch filter sock and its removal; and removal of 12 light poles. - Bridge items include 65 LF of demonstration shaft, 17,080 LF of steel HP 14 x 73 piles, and one complete stay-cable system. Test-pile materials documented in the attachments include four 50-foot HP 14 x 73 H-piles and two 50-foot PZC-26 sheet piles. - The stay-cable system must include HDPE sheathing and retain its integral passive ice-management profile. The specified system is subject to project-specific FHWA concurrence and Buy America compliance review; covered materials cannot be incorporated before required written concurrence and acceptance of compliance documentation. No corrosion-protection coating is required. - A licensed engineer must observe 10% of micropile installation and all micropile proof testing. Pile-driving monitoring reported vibration below structural-damage thresholds, while noise and vibration exceeded human-disruption limits at the Courthouse; monitoring during construction is recommended. - Salvage requirements include 600 feet of bridge railing for public distribution, 40 feet of railing and posts for public art, and at least 16 feet of variable-depth steel girder. Lead was detected in existing bridge paint, requiring applicable removal precautions and protection of the public, utilities, and nearby structures. - The MSE assessment covers seven walls and specifies a 250 psf surcharge, 75-year service life, and minimum 4-foot embedment. Wall 7 requires longer-than-typical reinforcement and aggregate-pier ground improvements; settlement improvements are planned beneath Walls 5 and 6. - The engineer’s opinion of probable cost is $123,000,000.

Description

The City of Cedar Rapids is soliciting bids for replacement of the existing bridge over the Cedar River and construction of flood-control system components. The work generally includes demolition of the existing bridge, construction of a new cable-stayed river bridge, approach roadways, traffic improvements, sidewalks and trail reconstruction, utility reconstruction, and lighting. The project is located from 1st Street SW to 3rd Street SE along 8th Avenue SE/SW and Diagonal Drive SW in Cedar Rapids. The stated engineer’s opinion of probable cost is $123,000,000, and final completion is 1,250 calendar days.

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