COMPLIANCE INFO_1999-2001 - Laserfiche WebLink

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6. XNCHORfNG TANKS ACAUTION !♦ I:." rr: I I -' .".171 ' I: the tank or '... I . property. 6.1. DEADMAN ANCHORS 6.1.1. A deadman is typically a reinforced concrete beam. 6.1.2. The length of the deadman is typically equal to the length of the tank. 6.1.3. A deadman may be fabricated in multiple sections as long as the total length is not decreased and each section contains at least two balanced anchor points. 6.1.4. The width and thickness of the deadmen depend on the tank diameter, water -table height, number of attached collar risers and burial depth. 6.1.5. Deadmen should be designed according to the American Concrete Institute (ACI) code. 6.1.6. Refer to TABLE 6-1 for typical deadmen dimensions given the situation of an empty tank with a burial depth of 3 feet, with groundwater to grade and with one attached collar riser. Tank Diameter Typical Deadman Dimensions (Width x'Depth) 4' 6" x 6" 6' 12" x 12" 8' 12" x 12" 10' 18" x 12" 12' 36" x 8" TABLE 6-1 6.1.7. Tanks of 10 -foot diameter and a capacity of 30,000 gallons or more may require larger deadmen than those in TABLE 6-1, depending on burial depth, to offset buoyancy. Contact technical support at Xerxes Minneapolis for further information. 6.1.8. Lay the deadmen in the excavation parallel to the tank and outside of the tank "shadow." (See FIGURE 5-3.) 6.1.9. In multiple tank installations with deadmen: • each tank will have its own set of deadmen (one deadman may be used between two tanks if the deadman is double in width); • a separate anchor point must be provided for each hold- down strap; • the minimum spacing between tanks must be no less than twice the width of a single deadman. 12 6.2. XERXES DEADMAN ANCHORS 6.2.1. A Xerxes -supplied deadman is pre-engineered and sized to the tank ordered. As with any deadman, water -table height, number of attached collar risers and burial depth must be considered. 6.2.2. Placement of a Xerxes deadman is the same as a standard deadman. (See FIGURE 6-1.) 6.2.3. A Xerxes deadman is supplied with 3/4 -inch -diameter, plated U -bolts. These bolts protrude up through the slots in the deadman and are held in place with cotter pins. 1 Only use the U -bolts when lifting and positioning the deadmen. A spreader bar may be required to lift longer sections of deadmen. Use guy ropes to guide the anchors when lifting. Failure to do so could result in death, serious personal injury or property damage. 6.2.4. The U -bolts can be moved and positioned to match the hold-down strap locations on the tank (marked by arrowhead symbols No --4. 6.2.5. When using these deadman anchors in man -out -of -hole strapping applications, align the U -bolts with the proper ribs before setting them in the hole. 6.2.6. Care should be taken to keep backfill from entering the U -bolt slot until final adjustment is made. 6.2.7. The deadmen are to be butted together at the tank center, on each side of the tank when multiple sections are used. 6.2.8. Use one U -bolt per strap end and only one strap per U -bolt. 6.3. ANCHOR SLAB 6.3.1. An anchor slab is typically a reinforced concrete base. 6.3.2. The total length of the slab must be at least the same as the length of the tank. 6.3.3. The minimum slab thickness is 8 inches. 6.3.4. The width of the slab depends on the tank diameter. The slab must extend a minimum of 18 inches [12 inches for 4 -foot - diameter tanks] beyond the width of the tank. 6.3.5. Refer to TABLE 6-2 and FIGURE 6-1 for anchor -point dimensions. 6.3.6. Provide a separate anchor point for each hold-down strap. 6.3.7. All anchor points must be engineered to withstand the tank's buoyancy forces. 6.3.8. When using a concrete base slab, allow sufficient depth in the excavation for 12 inches of bedding material below the tank. (See FIGURE 6-1.)