Agenda - Public Works Committee - 06/21/2022

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Public Works Committee Meeting Date: 06/21/2022 Submitted For: Joe Feriancek, Engineering/Public Works By: Joe Feriancek, Engineering/Public Works 5.3. Title: Consider Recommending City Council Approving Plans and Specifications and Authorizing Advertisement for Bids for Autumn Heights Street Reconstructions, Improvement Project #22-02 Purpose/Background: Purpose: The purpose of this case is to consider recommending City Council approving plans and specifications and authorizing advertisement for bids for Autumn Heights Street Reconstructions, Improvement Project #22-02. Background: City Improvement Project 22-02 proposes to reconstruct the streets within the Autumn Heights subdivision, generally located along both sides of Armstrong Boulevard between the 167th and 169th blocks. The streets total approximately 8,500 linear feet (1.61 miles) in length, and are 24-foot wide rural section with drainage swales along both sides of the streets. A street segment summary is attached to this case. Project History • 2022 — 2031 Capital Improvement Program — listed as street reconstruction for 2022 • August 10, 2021 City Council accepted proposals for geotechnical report and topographic survey • August 24, 2021 City Council accepted proposals for utility testing . October 26, 2021 City Council ordered plans and specifications Pavement History The streets within the subdivision were built between 1977 and 1988. Pavement maintenance has included an initial round of crack seal / seal coat improvements, and overlay between 1990 and 2002, followed by 2 more rounds of crack seal / seal coat improvements in 1997 and 2004. Maintenance crews have performed patching over the last several years, including extensive spray patching. 2021 PASER values we 2 for all street segments. PASER values of 2 are as low as any street segments within the City. Ground Penetrating Radar (GPR) was performed on the street segments. Bituminous pavement thickness averages were between 3.3 and 3.9 inches thick on the various street segment. Aggregate base thickness was found to vary between 3.1 and 4.0 inches thick. The weighted average total section thickness was 7.0 inches. Proposed Improvements Staff review of the geotechnical report found the majority of sub -base material to be poorly graded sand and poorly graded sand with silt, these materials are well suited for pavement support and are considered non -frost susceptible and are also free draining materials. An approximately 600-foot section of 167th Lane east of Armstrong Boulevard found undesirable materials in the to 3 feet of sub -base. These materials are proposed to be replaced with 2 feet of select granular material on top of geotechnical fabric. Staff is proposing to use the current standard City pavement section of 4-inches aggregate base, and 3.5-inches new bituminous pavement. The 4-inches of aggregate base is proposed to be composed of recycled reclamation material. This project proposes to add a half cul-de-sac to the dead end on 169th Avenue west of Rabbit Street. The half cul-de-sac can be constructed within the existing right-of-way on the south half of 169th Avenue. Extensive review found no right-of-way or roadway easements currently exist for the not half of 169th Avenue. Internal Staff discussions with public safety and public works support this proposed improvement. Any improvements beyond the