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Orange County Eubanks Road C&D Landfill <br />Permit Technical Specifications <br />Revised March 15, 2021 <br />Section 02221 - 3 <br /> <br /> <br />part of the trench bottom that is excavated below the required level shall be <br />backfilled with approved granular material and compacted to a minimum 95 percent <br />of theoretical maximum density as determined by ASTM D698. <br /> <br />3.08. Trench Width <br /> <br />Trench width at the ground surface may vary with and depend upon depth, type of soils, and <br />position of surface structures. The minimum clear width of the trench, sheeted or unsheeted, <br />measured at the springline of the pipe should be one foot greater than the outside diameter of <br />the pipe. The maximum clear width of the trench at the top of the pipe should not exceed a <br />width equal to the pipe outside diameter plus two feet. If the above defined trench widths <br />must be exceeded or if the pipe is installed in a compacted embankment, pipe embedment <br />should be compacted to a point of at least 2.5 pipe diameters from the pipe on both sides of <br />the pipe or the trench walls, whichever is less. Excavation at manholes and similar structures <br />shall be sufficient to provide 12 inches in the clear between the outside of the structure and <br />the embankment or sheeting. <br /> <br />3.09. Unsuitable Subgrade <br /> <br />A. Unstable Foundation <br /> <br /> When an unstable foundation is encountered which will not provide adequate pipe <br />support, additional trench depth shall be excavated to a stable foundation and <br />backfilled with approved granular material. <br /> <br />B. Rock <br /> <br /> Where the bottom of the trench at subgrade is rock, excavation shall be carried at <br />least six inches below the specified subgrade and restored to subgrade with <br />compacted approved granular material. <br /> <br />3.10. Bedding <br /> <br />Pipe bedding must be tested by the CQA Engineer in order to meet the following <br />requirements: <br /> <br />A. Fine aggregate bedding shall meet requirements for fine aggregates, Section 1005, <br />NCDOT Standard Specifications for Roads and Structures. <br /> <br />B. Coarse aggregate bedding shall meet requirements for coarse aggregates, Section <br />1005, NCDOT Standard Specifications for Roads and Structures. <br /> <br /> Compact pipe bedding by tamping or rodding to reduce settlement. <br /> <br />DocuSign Envelope ID: 0844D1D6-E311-4FC5-8B5B-BB1E27A908ED