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Buoyancy of Underground Tanks 9/13/2022 <br />Fiberglass Straps with Deadman Anchors <br />"Bold Typed Items are Input Values" <br />Underground Tank Description: <br />15K GSII TANK <br />TOP WATER LEVEL <br />Tank Model: <br />GSII <br />Outer Tank Diameter (Inches): <br />115 <br />Tank Length (Inches): <br />341 <br />Tank Capacity (Gallons): <br />15332 <br />Tank Buoyancy: <br />127,903 <br />Primary Shell Thickness (Inches): <br />0.25 <br />Secondary Shell Thickness (Inches): <br />0 <br />Accessories Weight Extra <br />1441 <br />Calculated Tank Weight: <br />11,649 <br />11,649 <br />Sumps / Enclosures <br />Quantity of Item 1 enclosures <br />1 <br />Item 1: "Diameter" (Inches): <br />42 <br />Item 1: "Height" (inches): <br />60 <br />OK <br />Quantity of Item 2 enclosures <br />1 <br />Item 2: "Diameter" (Inches): <br />48 <br />Item 2: "Height" (inches): <br />60 <br />OK <br />Buoyancy contributed by enclosures: <br />0 <br />Net Tank Buoyancy: <br />116,254 <br />Concrete Slab at Grade <br />Concrete weight / cubic foot: <br />150 <br />Surface Concrete Slab Thickness (Inches): <br />6 <br />Weight of concrete Slab: <br />28,162 <br />(Slab size:24">tank diameter, 48"5 tank length) <br />Burial and Water Table Depth <br />Net saturated soil weight to overcome buoyancy <br />57.6 <br />Saturated backfill weight / # cubic foot: <br />120 <br />Dry backfill weight / # cubic foot: <br />100 <br />Tank Burial Depth, Top of tank to grade (Inches): <br />60 <br />Elevation of water table, " 0 inches" is flooded hole: <br />60 <br />Weight of Backfill directly over tank: <br />138,677 <br />Overburden lost due to sump size and number: <br />11648 <br />Net Overburden = <br />127,028 <br />Deadman Configuration <br />Deadman Anchor width (Inches): <br />0 <br />OK <br />Deadman Anchor height (Inches): <br />0 <br />Aside Parameters <br />Deadman anchor length (Inches): <br />0 <br />OK <br />Deadman Contribution toward Overcoming Buoyancy: <br />0 <br />Total Weight Concrete, Overburden & Deadman contributions: <br />155,190 <br />If =( ) then insufficient Buoyancy Results: <br />38,936 <br />SAFETY FACTOR: <br />1.2 <br />1.30 ACCEPTABLE <br />Fiberglass Holddown Straps <br />Required <br />Net Bouyancy reaction to be overcome by straps <br />38,936 <br />Number of Holddown straps used on tank: <br />6 <br />Strap Size: 3/16" x 2" each <br />Maximum Allowable Load associated with strap: <br />28,500 <br />pounds / strap <br />Straps combined strength to overcoming buoyancy: <br />171,000 <br />pounds <br />SAFETY FACTOR: <br />1.50 <br />4.39 ACCEPTABLE <br />Required <br />Special Note: <br />Deadman, holddowns, overburden backfill and concrete cover all act together as a complete system. <br />If anyone of these elements is not fully utilized, holddown system may not function adequately. <br />Disclaimer Statement: <br />The attached information is supplied to you for information purposes only. <br />Therefore, Modern Welding Company, their officers, directors nor subsidiaries there of accept any / no <br />responsibility for the use of this information covered within. This information is advisory only and the use <br />of the material and methods is solely at the risk of the user. <br />