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UNDEOROUND TANK INSTALLATION Page 2 <br /> Design for Anchorage Against Buoyancy Guide <br /> STEP 3 -Determine the Total Net Uplift <br /> Multiply the tank length by the Net Buoyancy to determine the Length <br /> Buoyancy. Subtract the weight of the tank heads from the Length <br /> Buoyancy to determine the Total Net Uplift Tank Length (5) 7' ft. <br /> Net Buoyancy (20) i z e lbs/t <br /> 2io 65% ft. Tank Length (5) Head Weight (21) / lbs <br /> x 2% O lbs/ft Net Buoyancy (20) <br /> ^ lbs TANK BUOYANCY <br /> i 2�jo lbs Tank Buoyancy (22) <br /> lbs Weight of Tank Heads (21) <br /> ® /`/ lbs TOTAL NET UPLIFT <br /> STEP 4-Determine If Design Is Required <br /> If the Total Net Uplift determined in Step 3 is a negative number,then the <br /> tank will not be subject to uplift forces for the specified design conditions, <br /> no anchorage is required, and no further analysis is required. The owner <br /> should verify the design conditions with a qualified geotechnical engineer or <br /> hydrologist. <br /> If the Total Net Uplift determined in Step 3 is a positive number,then the <br /> tank will be subject to uplift forces for the specified design conditions. <br /> These forces must be counteracted by the backfill or, if the backfill by itself <br /> is insufficient, by the backfill and the addition of deadman anchors. <br /> Determine the Design Uplift Force and proceed to Step 5. <br /> !lbs Total Net Uplift (23) <br /> z4 x 1.50 minimum Safety Factor <br /> ® lbs DESIGN UPLIFT FORCE <br /> STEP 5 -Determine the Unit Weight of Backfill and Slab <br /> Separately determine the weight of backfill and slab materials for both the wet and <br /> dry conditions for Zones 1 &2. This weight will be determined in terms of unit <br /> weight per square foot of plan area. Add all of the individual weights to Dry HT, Zone 1 (13) ft. <br /> determine the Unit Weight of Cover. Wet HT, Zone 1 (14) ' 7 ft. <br /> Height Unit WT Dry HT, Zone 2 (15) n ft- <br /> of area of Marl Wet HT, Zone 2 (16) S = R <br /> © Unit weight of Dry Slab 1-3) -- ft x 150.0 = J lbs/sq ft <br /> Unit weight of Wet Slab ft x 87.6 = / lbs/sq ft <br /> ® Unit weight of Dry Backfill ft x 100.0 = lbs/sq ft <br /> Unit weight of Wet Backfill `�'� ft x 37.6 = ! Z lbs/sq ft <br /> ® UNIT WEIGHT OF COVER = -a-771_ lbs/sq ft of plan area <br />