Agenda - Council - 10/09/2018 - Laserfiche WebLink

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3. EXISTING CONDITIONS 3.1 Existing Pavement and Soil Conditions All streets proposed to be improved were constructed in 1991 with bituminous pavement, class 5 aggregate base, bituminous curb, and concrete storm sewer. The streets were constructed to a width of 29-feet from face -of -curb to face -of -curb. The streets are generally centered within a 66-foot wide right-of-way. The only pavement maintenance treatments applied to the street segments included cracksealing and sealcoating Ute Street and 154th Lane in 1996, and 153rd Court in 1998. Spot patching has been performed on an as -needed basis, and has been a yearly treatment recently. In 2017, Staff observed a PASER of 3 on all the street segments. In July of 2017, City staff recorded a traffic volume of 114 average annual daily traffic (AADT) on Ute Street north of Alpine Drive, and 43 AADT on Ute Street west of Roanoke Street. Traffic counts were not taken on 153rd Court, however it can be reasonably expected 153rd Court would have similar traffic volumes. The speed limit is 30 mph for these street segments. Braun Intertec was employed to complete a Geotechnical Exploration and Engineering Review for this project, which included five (5) soil borings spaced at approximately 600 feet along Ute Street/154th Lane and 1 boring in each cul-de-sac. The locations of the borings are shown in the Soil Boring Location Map in the Appendix of Braun's report, attached in Appendix C. The soil borings provide information on existing bituminous pavement and aggregate base course thicknesses, subsurface soil conditions, existing ground water elevations, and potential issues, which may be encountered during construction. All borings terminated at a nominal depth of 11 feet below the existing ground surface. There was no groundwater observed during the soil borings. Based on the work proposed and the lack of groundwater at a depth of 11 feet below the existing ground surface, groundwater is not anticipated to be a significant issue for work completed with this proposed project. The soil borings generally indicate the existing bituminous pavement thickness ranges between 3 to 4 inches, and aggregate base thickness ranges between 4 to 6 inches. The subgrade generally consists of poorly graded sand with silt at depths ranging from 2.0 to 6.0 feet below the top of pavement. Native alluvial soils consisting of poorly grades sand (SP) generally extend to the bottom of the borings (11 feet). Braun Intertec was employed to complete a ground penetrating radar (GPR) analysis for the project area, which included driving the GPR equipped vehicle throughout all street segments within the project area. A summary table and charts of the GPR Analysis are attached in Appendix C. The GPR data determined an average bituminous pavement thickness of 2.9 inches, and an average aggregate base thickness of 4.9 inches. The average street pavement and base section thickness was 7.7 inches, with a minimum section of 5.1 inches located on Ute Street, 91 feet south of the intersection with 154th Lane. Feasibility Report Stanhope Terrace Reconstructions City of Ramsey Project No. 18-00 Page 6