Duluth UDC § 910.01

1. Subgrade preparation shall be in accordance with Georgia DOT specifications and this Article, whichever is more stringent. 2. If any sections of the subgrade are composed of topsoil, organic, or other unsuitable or unstable material, such material shall be removed and replaced with suitable material and then thoroughly compacted as specified for fill or stabilized with stone or a geotextile or geogrid. 3. Fill shall be placed in uniform, horizontal layers not more than 8-inch thick (loose measurement). Moisture content shall be adjusted as necessary to compact material to 95% of maximum dry density 255 | P a g e Article Nine. Project Design and Construction Standards except for the top 12 inches which shall be compacted to 100% of maximum dry density. Engineering reports documenting moisture content shall be submitted to the City before moving forward. 4. After the earthwork has been completed, all storm drainage, water, and sanitary sewer utilities have been installed within the right-of-way as appropriate, and the backfill in all such ditches thoroughly compacted, the subgrade shall be brought to the lines, grades, and typical roadway section shown on the plans. Engineering reports documenting proof of said work shall be submitted to the City before moving forward. 5. Utility trenches cut in the subgrade shall be backfilled as specified herein. Compaction tests at the rate of one per 150 feet of trench shall be provided to verify compaction. City approval shall be required. 6. The subgrade must pass roll testing prior to placement of the base material. With the approval of the Planning Department, a geotextile or geogrid may be used to stabilize a subgrade that does not pass proofrolling. 7. When the street is to be used for construction traffic before the paving work is completed, a layer of stone (except crusher run) shall be laid as a traffic surface. This material shall not be used as a part of the base material. It may be worked into the subgrade, or it shall be removed before the base course is set up for paving 8. Provisions shall be made to drain low points in the road construction when the final paving is delayed. A break in the berm section is required when the curbing has not been constructed. After installation, drainage under the curb to side slopes is required, using minimum 4-inch diameter pipe sections.