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City of Ramsey <br />Project B1705491 <br />August 11, 2017 <br />Page 9 <br />D. Recommendations <br />D.1. Pavements <br />D.1.a. Subgrade Preparation and Proofrolls <br />For preparation of any exposed subgrades prior to placement of new pavement sections or reclaimed <br />aggregate (see below), we recommend proofrolling the subgrade soils with a loaded tandem -axle truck. <br />This will assist in identifying any soft or weak areas that will require additional soil correction work. Areas <br />that yield or rut more than 1 to 2 inches due to wheel traffic, depending on conditions, should be <br />corrected. Failed areas should be compacted, or if too wet, we recommend that the upper 1 to 2 feet of <br />the resulting subgrade be scarified, dried to a proper moisture content (see Table 6), and compacted to a <br />100 percent of its standard Proctor maximum dry density (ASTM D 698). <br />If there are areas that still cannot be compacted, we recommend subexcavating the unstable materials to <br />a minimum depth of 1 to 2 feet, depending on the outcome of the proofroll and the replacement <br />material. The soils should be replaced with suitable, properly compacted materials such as select <br />granular material, aggregate base or larger diameter crushed aggregate ("3-inch minus"). <br />D.1.b. Backfill and Material Compaction <br />We recommend compacting soils used as backfill for subcuts or material replacement to a minimum of <br />100 percent of standard Proctor density within 3 feet of the top of the subgrade. For fills more than <br />3 feet below final subgrades, 95 percent compaction is sufficient. The moisture content of the fill and <br />backfill should be as shown in the table below depending on the classification of the backfill soils. <br />Table 6. Compaction Recommendations Summary <br />Reference <br />Below pavements, within 3 feet of <br />subgrade elevations <br />Below pavements, more than 3 feet <br />below subgrade elevations <br />Below utilities <br />Relative Compaction, percent <br />(ASTM D 698 - Standard Proctor) <br />100 <br />95 <br />Moisture Content Variance from <br />Optimum, percentage Points <br />- 3/+3 (sandy soils) <br />- 2/+1 (clayey soils) <br />- 3/+3 (sandy soils) <br />- 2/+3 (clayey soils) <br />BRAUN <br />INTERTEC <br />