Slide 12 of 15
Notes:
- Similar to water heaters
- Many houses have tanks to store liquids such as water, fuel, or natural gas.
- Tanks are usually located outside the house and are raised up off of the ground.
- Tanks are vulnerable to tipping over.
- Tanks that contain any type of fuel are a concern because if they tip over and spill their contents, they can ignite and cause a fire
- What are the most important considerations when dealing with elevated liquid storage tanks?
- Bracing
- Brace the legs of the tank.
- Bracing the legs of the tank is needed for the same reason as bracing the cripple wall of a house. If the tank sways too far during the earthquake, the legs can become unstable and the tank will fall over.
- Provide braces in both directions on each side of the tank.
- Figure shows a properly braced tank
- Pads
- Provide a large enough concrete pad under the tank.
- Needed below the legs of the tank to spread out the overturning force and prevent a soil failure that would cause the tank to tip over
- A single pad under the entire tank is preferred.
- When casting the pad footing
- Cast in anchor bolts for attaching the legs of the tank to the concrete
- Place welded wire fabric in the footing to prevent cracking
- Be certain wire remains in the center of the concrete during the pour.
- Figure shows a correctly installed concrete pad
