The formula for calculating the depth of concrete pavements suggested by Goldbeck, is

• A. <img src="/_files/images/civil-engineering/highway-engineering/38-16-184-1.png">
• B. <img src="/_files/images/civil-engineering/highway-engineering/38-16-184-2.png">
• C. <img src="/_files/images/civil-engineering/highway-engineering/38-16-184-3.png">
• D. <img src="/_files/images/civil-engineering/highway-engineering/38-16-184-4.png">