Figure 2-2. Checking grade of tank foundation

TM 5-5430-209-12

ME 5430-209-12/2-2

Figure 2-2. Checking grade of tank foundation.

conditions;

therefore,

special

foundations

are

(3) After the tank is erected, stabilize the

necessary.

outer slopes with an asphalt base material to prevent

(1) Concrete Foundation Ring. Where tanks

washout of the soil material.

must be sited on alluvial deposits, flood banks, or in low

NOTE

wet areas, build a concrete foundation ring (fig. 2-3) of

Purpose of the foundation is to provide

the same diameter as the tank. Pour a continuous

drainage of water away from the tank so

concrete ring 12 inches thick and 2 feet high with its

that moisture will not accumulate and

base 18 inches below the ground surface. Provide drain

corrode the tank bottom.

pipes below the top of the ring but above ground level.

d. Surfacing. If the foundation materials or ground

Fill the ring with suitable foundation material. Compact

the fill to provide stable support for the tank bottom.

water contain alkali salts which will corrode the tank

Surfacing will be required in wet areas, especially if the

bottom, surfacing is required. Use a bituminous seal

water is salty or brackish. The side staves of the tank

coat, or work bituminous material into the top layer of

bear on the concrete ring when tank is erected.

foundation material. Tarpaper or roofing felt may be

used. It is a good practice to apply surfacing even when

the foundation material is not corrosive in order to

prevent seepage of water from the subsoil. Concrete

slab foundations are desirable if time, labor, and

material are available.

e. Special Foundations. Occasionally, tanks must

be built on sites which would not be used under ideal

2-2