INSTALL_2008 - Laserfiche WebLink

Home Browse Search

♦ 4' through 10' diameter tanks require: ❑ Minimum of 18" (24" preferred) between adjacent tanks. ❑ Minimum of 18" (24" preferred) between tank sides/ ends and the walls of the excavation. ♦ 12' diameter tanks require: ❑ 24" between adjacent tanks. ❑ 24" between tanks sides/ends, and the walls of the excavation (see figure 5). ♦ Muck, bog, peat, swamp or landfill type areas where the soil is soft or in areas with expansive clay soils. or have less than 750 lbs./sq. ft. cohesion perASTM D2166 (Test Methods for Unconfined Compressive Strength of Cohesive Soil), or have ultimate bearing capacity less than 3500 lbs./ sq. ft. ♦ In unstable excavation, tanks require: ❑ Minimum 18" (24" preferred) between adjacent tanks. (24" required for 12' diameter tanks). ❑ Minimum of 1/2 the tank diameter from ends and sides of tanks to excavation walls (see fig- ure 6). ♦ May require a reinforced concrete pad under tank. ♦ Contact soils consultant for recommendations. ♦ Filter fabric hole liner is recommended for soils (see"Fil- ter Fabric" section for list and further requirements): ❑ With less than 250 lbs./sq. ft. cohesion or, ❑ With ultimate bearing capacity of less than 500 lbs./ sq.ft. A5. BURIAL DEPTH AND COVER Excavation Depth ♦ All tank holes must be deep enough to: ❑ Allow a minimum of 12" and a maximum of 24" required backfill bed over the hole bottom or con- crete pad. Traffic Pad Reinforcement ♦ The reinforcements in the concrete traffic slab must be properly sized for job conditions and traffic loads to as- sure concrete surface pad integrity. Pad Dimension ♦ Paving at grade must extend at least 12" beyond tank perimeter in all directions (see figure 7). FIGURE 7 -4.= f.V �� rjirimli ��,,y7 A -n I 7' MJaxirrum i Maximum Burial Depth ♦ UL requirements specify that the depth of cover must not exceed 7' (see figure 7). For all size tanks. ❑ For both traffic and no traffic conditions. ♦ For deeper burial depths, contact Tank Technical Support. Minimum Burial Depth No Traffic Load and No Mechani- cal Anchoring (4'— 1 O'diameter tanks) NOTE: When mechanical anchoring is required, refer to chart (section A7) for minimum burial depths (see figure 8). FIGURE �Qinfnr. ncr�ta • 17� Rsda.nn ♦ Tanks need a minimum cover of 24" backfill OR 12" of backfill plus 4" reinforced concrete (see figure 8). ♦ Local codes may require deeper minimum burial depth. (12' diameter tanks) ♦ Tanks need a minimum cover of 42" backfill OR 38" back- fill plus 4" reinforced concrete. Minimum Burial Depth H-20 Traffic Loads and No Me- chanical Anchoring (4' -10' diameter tanks) NOTE: When mechanical anchoring is required, refer to chart (section A7) for minimum burial depths.