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equipment. 9.3.2. The lift thickness of structural backfill after compaction shall not exceed 6 inches. 9.3.3. The in-place moisture content of the select and structural fill shall be within minus -3 percent and +1 percent of the optimum. To assure maximum consistency, water, as required, should be added to the materials at the borrow area. 9.4. RIPRAP BEDDING 9.4.1. Riprap bedding (or geosynthetic fabric) shall be placed under all areas where riprap is to be placed. 9.4.2. Riprap bedding shall be placed in maximum 6-inch loose layers and compacted by two passes of vibratory equipment. 9.4.3. Bedding shall be spread in such a manner as to avoid segregation and assure a uniform layer. 9.4.4. Riprap bedding thickness shall be 6 inches of riprap bedding material. 9.5. RIPRAP 9.5.1. Riprap shall be placed over bedded areas to conform to the Drawings. 9.5.2. Riprap shall be placed to ensure a relatively uniform distribution of rock sizes. 9.5.3. Where possible, existing riprap in the Work area shall be reclaimed and stockpiled for reuse. Addi- tional riprap shall be obtained from Area D. 10. PAVEMENT CONSTRUCTION 10.1. GEOGRID INSTALLATION 10.1.1. Geogrid shall be installed strictly in accordance with the manufacturer's published directions. 10.1.2. Geogrid shall be laid on the proof-rolled subgrade or as directed by the Engineer. 10.1.3. The correct orientation (roll direction) of the geogrid shalt be verified by the Contractor. 10.1.4. Geogrid may be temporarily secured in place with staples, pins, sand bags, or backfill as required by fill properties, fill placement procedures, or weather conditions, or as directed by the Engineer 10.1.5. .Geogrid soil reinforcement shall be connected/spliced when required to provide continuity of tensile resistance. Geogrids manufactured using polyolefins (e.g., HDPE and PP) shall be connected with a mechanical polymer bar. Geogrids manufactured of polyester shall be connected by sewing with Kevlar sewing thread perpendicular to the direction of loading at the ends of the materials. 10.1.6. Overlap connections may be used if the Contractor provides the Engineer independent test documentation which demonstrates that the load/deformation characteristics of the overlap of geogrid materials is equal to or exceeds those of the geogrid. The minimum overlap shall be 5 feet. 10.2. AGGREGATE BASE COURSE INSTALLATION 10.2.1. Aggregate base course material shall be placed, spread, and compacted in such a manner that minimizes the development of wrinkles in and/or movement of the geogrid. 10.2.2. Tracked construction equipment shall not be operated directly on the geogrid. A minimum fill thickness of 6 inches is required prior to operation of tracked vehicles over the geogrid. Turning of tracked vehicles should be kept to a minimum to prevent tracks from displacing the fill and damaging the geogrid. Rubber-tired equipment may pass over' polyolefin geogrid reinforcement at slow speeds, less than 10 mph. Sudden braking and sharp turning shall be avoided. Rubber-tired equipment shall not pass over polyester geogrid reinforcement. A minimum fill thickness of 6 inches is required prior to operation of rubber-tired equipment over polyester geogrid reinforcement. 10.2.3. Aggregate base course material shall be placed in maximum 8-inch loose lifts or 6-inch compacted lifts, and compacted to at least 95% of the standard Proctor Density (ASTM D698). SPECIFICATION A EARTHWORK PAGE7