2004-013.C - Laserfiche WebLink

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r r 2 . Trench grade for pipe or structures not requiring special bedding rmaterial shall be defined as the grade of the bottom surface of the utility or structure to be constructed or placed within the trench. Such shaping of the trench bottom, as may be required to provide suitable bedding, shall be ' considered to be a part of this work. Trench grade in non-cushioning material shall be defined as 6 inches below the outside of the bottom of the utility, which 6 inches shall be backfilled with suitable bedding material . Unauthorized excavation below trench grade shall be backfilled to trench grade and suitably compacted by the Contractor without additional cost to the Owner. Final trimming and grading of trench bottom shall be done manually. r6. BACKFILL AND BEDDING MATERIALS A . Type 1 - Type 1 material shall be either well-graded crushed stone or crushed gravel meeting the requirements of ASTM Designation C33 -71a, Gradation 67 (3 /4 inch r to No . 4 Sieve) or air cooled blast furnace slag along or in combination with crushed stone and/or crushed gravel conforming to ASTM Designation C33 -71a requirements . This material shall be used primarily for pipeline and manhole foundations . r B . Type 2 - Type 2 material shall be unclassified material obtained from the Contractor' s excavations and approved by the Engineer. The material shall be substantially free from wood, roots, humus, peat, muck, and other organic materials , and shall not contain clods, stones, masonry rubble, and the like, greater than 6 inches through the largest dimension. In general , the material shall consist of sand, loam, sandy- loam, clayey- sand, gravel , or crushed stone . C . Type 3 - Type 3 material shall be select granular material , free from organic matter, of such size and gradation that the desired compaction can be readily ' attained and shall meet the requirements for A3 material according to the Revised Bureau of Public Roads Classifications . Material from the Contractor' s excavations may be used, if it meets the above requirements . ' Otherwise it must be imported. 7. BEDDING AND FOUNDATIONS iA . CLASS A (CONCRETE CRADLE OR CONCRETE ARCH BEDDING) 1 . This class of bedding shall be used only where specifically shown in the Drawings or directed by the Engineer. If the use of a concrete cradle is required the pipe shall be bedded in a monolithic cradle of a 1 , 500 PSI r concrete with a minimum thickness equal to 1 /4 the outside pipe diameter or to a minimum of four inches under the barrel , whichever is greatest, and extending up to the sides of the pipe to a height equal to 1 /2 of ' the outside pipe diameter. The cradle shall have an overall width equal to 1 - 1 /4 of the outside diameter of the pipe or a minimum width equal to the outside diameter of the pipe plus eight inches, whichever is greater. rC ; \ Down1oad \ techspec - 02403 . doc 02403 - 3