INSTALL 2003 - Laserfiche WebLink

Home Browse Search

There shall be no mixing of backfill materials within the installation. EXCAVATION Finished grade Always follow OSHA guidelines for safety when dealing with tank excavations. typically a to 4 ft.'.:.:.:.:::::::.•. :::.: The excavation should provide adequate room for tanks, piping and associated equipment used for placement and compaction of backfill materials. The slope of excavation wall is determined by OSHA and soil conditions. Take appropriate action to make your excavation a ♦ 12'. "safe place"to work. 1 V. The excavation shall be free of any sharp, hard objects that `.::`'' : Special might damage the exterior coating of the tank. Special care placement and shall be taken not to allow foreign matter to be introduced into compaction required the tank excavation. Never place tanks directly on timbers, concrete pad, wooden or cement cradles or beams of any sort. Failure to achieve and maintain 85% compaction density For proper tank support from backfill, adequate room shall be throughout the excavation will void warranty of the storage left for workers to place and compact backfill material under the bottom 120 degrees of each tank. If tanks are anchored mechanically, additional clearance between tanks and excavation wall may be required. The bottom of the excavation shall be suitably graded and leveled. The foundation for each tank shall be a minimum layer of one of the following: °°f, :' ;'''• a. 12 inches of clean inert compacted sand, r _=; b. 12 inches of rounded pea gravel ;>Y : c. 12 inches of gravel crushings. r';::;?=;SG,':?>' If a concrete pad is used, the same depth of bedding ,`% .'_ requirements apply. There shall be a minimum clearance of 12 inches from the =``~ outside edge of the tank to the inside edge of the excavation wall. This distance shall remain true for the entire perimeter surrounding the tank. Multiple tank installation also require a minimum of 12 inches With the use of mechanical compactors, care must be exercised between tank measured from each outside edge. not to damage tank or its corrosion protection coating. For proper support and the prevention of movement of tank, Note: Do not mix different backfill materials within the bedding and backfill require adequate compaction. excavation. If sand is used as bedding and backfill material, an 85% Special Note: Maximum burial depth from top of tank to top compaction density must be maintained. Compaction density of grade is 5'-0". Consult"Modern subsidiary" if deeper burial applies to the bedding, backfill around the tank and backfill depths are required. material covering tank to grade. Sand should be compacted in TANK DEFLECTION 8" to 12" lifts to attain a 85% Standard Proctor Density. Moisture is an important ingredient in attaining compaction. For tank's warranty to be implemented, inside vertical tank Use ASTM-D-698 to determine the maximum dry density and deflection measurements must be taken and documented on optimum moisture content of the material. Modern's Installation Checklist. Measurements of the tank's inside diameter shall be taken. Use an opening located closest Pea gravel and crushed rock are relatively self compacting, to the tank's center for this measurement. Measurements are however, to prevent voids under tank bottom, all bedding and required before backfilling and again at completion of the backfill materials must be forced under the lower 120 degree backfilling process to final grade. section of the tank bottom.