2011-024 - Laserfiche WebLink

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SUBGRADE 1 ) DESCRIPTION A) The subgrade will be constructed such that after being compacted it will conform to the line , grade , and cross sections as shown on the Drawings . Shoulders shall be stabilized and compacted as specified herein for subgrades . 2) FLORIDA BEARING VALUES A) The subgrade shall have a minimum bearing value as shown on the plans . 3 ) CONSTRUCTION DETAILS A) The subgrade shall be shaped , graded , and rolled to conform to the lines and grades as shown on the Drawings . Fine grading of the subgrade to its final profile shall be accomplished after the existing ground has been excavated as close as possible to the design elevations . In fill areas , fine grading of the subgrade shall be accomplished after fill is spread and compacted in accordance with Section SW-3of these Specifications - " Backfill and Compaction ' . B) All drainage culverts and utility conduits which will be installed under the pavement shall be installed prior to the final shaping and compaction of the subgrade . 4) COMPACTION A) The top of the subgrade in both cuts and fills shall be compacted to . A minimum of 98 percent of the maximum dry density to the depth specified on the Plans . The required density shall be maintained until the base course has been constructed . The subgrade shall be compacted with an approved self propelled steel drum or pneumatic tired roller weighing not less than 8 tons . All hollows and depressions which develop under rolling shall be filled in with suitable material . The process of grading and rolling shall be repeated until no depressions develop . After compaction , the top surface of the fine grade shall be true to line and grade at all locations . If the fine grade becomes rutted or displaced due to any cause whatsoever, the Contractor shall regrade it and recompact it . Ditches , drains , and swales shall be maintained along the completed subgrade section after their construction . B ) In no case shall the Contractor proceed to construct the base course on the subgrade until the subgrade has been tested for Florida Bearing Values and compaction , line and grade is checked , and approval given by the Engineer, 5 ) STABILIZED SHOULDERS A) Stabilized shoulders shall be constructed on each side of the paved roadway section to the width , depth and slope as shown on the Plans and Typical Sections . The stabilized shoulder material shall have a minimum Florida Bearing Value of 50 pounds per square inch as determined by the Florida Bearing Value Test . In an area where the bearing value is less than 50 psi , stabilizing material approved by the Engineer shall be furnished by the Contractor, spread , and mixed thoroughly throughout the entire depth and width of the stabilizing limits . No specific density will be required and compaction shall be only to the extent directed by the Engineer. 6 ) COMPACTION TESTING A) In general , Florida Bearing Value tests on the subgrade shall be taken at approximately 300 lineal foot intervals . Exact locations will be designated by the Engineer. B) The maximum dry density of the subgrade material shall be determined by the Modified Proctor Test using the procedure as described by ASTM D1557 or AASHTO-T180 (Method A) . In general , there shall be one Modified Proctor Test per 300 lineal feet at a location which is representative of the type of subgrade material used on the project. Each material which is RP- 1 - 1