Agenda - Council - 01/24/2017 - Laserfiche WebLink

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4.1.3 Geotechnical Considerations Northern Technologies, Inc. (NTI) completed a Geotechnical Exploration and Engineering Review including thirteen (13) soil borings spaced at approximate 200 foot intervals along Alpine Drive. The locations of the borings are shown in the Boring Location Diagram in Appendix C of NTI's report, attached in Appendix C. NTI recommends completing a full reconstruction with subgrade corrections and the removal and replacement of all concrete curb and gutter. This work would result in project costs approximately twice as much as the current estimate included in this report, and would result in significant traffic impacts during construction. WSB completed four(4) pavement cores along Alpine Drive as shown in their Pavement Evaluations and Recommendations report, attached in Appendix C. WSB recommends leaving all intact existing curb and gutter in place, which staff estimates accounts for over 80% of the existing curb and gutter, which is only 15 years old. WSB also recommends reconstructing only the recycled concrete base and bituminous pavement using a Full Depth Reclamation process. In total, this work is estimated to cost half as much as a total reconstruction yet would result in a pavement design life of 30-plus years. In considering that the remaining curb and gutter will likely need to be replaced in about 40 years, a total reconstruction could be evaluated at that time. Another benefit to this design is that it would result in minimal impacts to traffic during construction. 4.1.4 Other Considerations Driveways: Existing driveway aprons will need to be reconstructed to varying degrees. The limits of construction will vary with each driveway apron based on the elevation of the street abutting the driveway and the driveway pavement type. During design, staff will evaluate the construction limits for each driveway and will incorporate this into the plans, but as with all street reconstruction projects the exact limits of construction will be determined in the field during construction. Right-of-entry forms will be obtained from private property owners if work is required outside City right-of-ways and easements. Irrigation Systems: Developed properties along the project corridor may have private irrigation systems. However, impacts to these systems would only occur if the existing curb and gutter is being removed and replaced. In the past, the City has typically repaired private irrigation systems that are damaged as part of a street reconstruction project. However, staff will be requesting Council permission to change this practice on all future projects by instead notifying property owners of pending construction at least 15 business days in advance to allow them time to move their irrigation systems out of harm's way before work begins. Parking Restrictions: Parking is currently provided intermittently along one side of the streets and is not currently restricted except for overnight parking per City code. During this project, parking will be restricted during allowable working hours. Feasibility Report Alpine Drive Reconstruction City of Ramsey Project No.I7-0I Page 7