Agenda - Council - 04/14/2020 - Laserfiche WebLink

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City of Ramsey Project B2001583 March 5, 2020 Page 3 Recommendations Prior to installing the drain tile system, we recommend cleaning up and reconstructing the in slopes along both sides of the roadway between Stations 87+00 and 90+00. This will remove any buildup of non - permeable soils, and allow for proper day lighting of the aggregate base and subgrade soils out to the in slopes. We recommend the in slopes be maintained at 3H:1V, or flatter along the alignment. In addition, we recommend reconstructing the ditches along both sides of the roadway between Stations 87+00 and 90+00. If feasible, we recommend re -grading and subcutting the existing ditch bottoms 1 foot between Stations 87+00 and 88+00 and 2 feet between Stations 88+00 and 90+00 to allow for more defined drainage along the roadway. We recommend incorporating a minimum of 12 inches of select granular material meeting the MnDOT Specification 3149.2.B.2 below the aggregate base. We recommend installing a 4-inch perforated PVC pipe with geotextile wrap directly beneath the bottom of the aggregate base section within the sand subbase layer. These drains should be placed perpendicular to the roadway at 50-foot intervals between Stations 88+00 and 90+00. The drain tile system should be day lighted within the sand subbase section out to the edges of the roadway and discharge a minimum of 1 foot above the bottom of the re -graded ditch. We have included a typical drawing from MnDOT's Standard Plan 5-297.433 for Typical Edge Drain and Discharge Cross Section for your reference. Figure 1. Typical Edge Drain and Discharge Cross Section I FT. MIN. SHOULDER DRIVING LANE 2 7.. MIN. 7 F• 4.. PRECAST SEE SUBSURFACE DRAIN BET AILS CONCRETE HEADWALL a 4" DIA. TP PIPE DRAIN SECTION VIEW TYPICAL EDGE DRAIN AND DISCHARGE CROSS SECTION 0 SEE TABULATION FOR LOCATIONS ) BRAUN INTERTEC