What is the minimum thickness and depth required for a concrete ringwall?

• A. 8 inches thick and 1 foot deep
• B. 10 inches thick and 1.5 feet deep
• C. 12 inches thick and 2 feet deep
• D. 14 inches thick and 2.5 feet deep

Answer: (C)

The minimum thickness and depth of a concrete ringwall are critical parameters that ensure the structural integrity and support for a welded tank storing oil. According to API 650, the design of a concrete ringwall must accommodate not only the weight of the tank itself when filled but also other factors such as soil conditions, potential seismic activity, and the environmental impacts around the installation site.

Choosing 12 inches thick and 2 feet deep for the concrete ringwall provides a robust and stable foundation. This thickness ensures that the ringwall can handle both vertical loads from the tank and lateral pressures from the surrounding soil. A depth of 2 feet allows for proper anchoring into the earth, reducing the risk of movement or settling that can affect the tank's performance.

This specific combination emphasizes the need for substantial foundations in tank construction to prevent failure. It reflects industry standards and best practices for safety and durability, making it a prudent choice in civil and structural engineering for oil storage facilities.

The other options present varying dimensions that may not align with the generalized requirements for appropriate support, potentially leading to structural vulnerabilities in real-world applications. Proper adherence to established specifications like those in API 650 is essential for ensuring that the tank system functions effectively over its lifespan.