Utility Excavations <br />1. Utility excavations are to be excavated to the design depth for bedding and placement and shall <br />not be over-excavated. Trench widths shall only be of sufficient width to allow placement and <br />proper construction of the utility and backfill of the trench. <br />2. Backfilling of a utility trench will be dependent on its location, use, depth, and utility line material <br />type. Trenches that are required to meet structural fill specifications, such as those under or near <br />buildings, or within pavement areas, shall have granular material strategically compacted to at <br />least the spring-line of the utility conduit to mitigate pipeline movement and deformation. The <br />initial lift thickness of backfill overlying the pipeline will be dependent on the pipeline material, <br />type of backfill, and the compaction equipment, so as not to cause deflection or deformation of the <br />pipeline. Trench backfill shall conform to the General Earthwork specifications for placement, <br />compaction, and testing of structural fill. <br />Geotextiles <br />1. All geotextiles shall be resistant to ultraviolet degradation, and to biological and chemical <br />environments normally found in soils. Geotextiles shall be stored so that they are not in direct <br />sunlight or exposed to chemical products. The use of a geotextile shall be specified and shall meet <br />the following specification for each use. <br />Subgrade/Aggregate Separation <br />Woven or nonwoven fabric conforming to the following physicalproperties: <br />• Minimum grab tensile strength <br />ASTM Method D-4632 <br />• Minimum puncture strength (CBR) <br />ASTM Method D-6241 <br />• Elongation <br />ASTM Method D-4632 <br />• Maximum apparent opening size <br />ASTM Method D-4751 <br />• Minimum permittivity <br />ASTM Method D-4491 <br />Drainage Filtration <br />Woven fabric conforming to the following physical properties: <br />• Minimum grab tensile strength ASTM Method D-4632 <br />• Minimum puncture strength (CBR) ASTM Method D-6241 <br />• Elongation ASTM Method D-4632 <br />• Maximum apparent opening size ASTM Method D-4751 <br />• Minimum permittivity ASTM Method D-4491 <br />Geogrid Base Reinforcement <br />180 lb <br />371 lb <br />15% <br />No. 40 <br />0.05 s-1 <br />no lb <br />220 lb <br />50% <br />No. 40 <br />0.5 s-1 <br />Extruded biaxially or triaxially oriented polypropylene conforming to the following physical properties: <br />• Peak tensile strength <br />lb/ft <br />• Tensile strength at 2% strain <br />lb/ft <br />• Tensile strength at 5% strain <br />lb/ft <br />• Flexural Rigidity <br />• Effective Opening Size <br />rock size <br />ASTM Method D-6637 <br />925 <br />ASTM Method D-6637 <br />300 <br />ASTM Method D-6637 <br />boo <br />ASTM Method D-1388 250,000 mg-cm <br />ASTM Method D-4751 1.5x <br />