How to calculate concrete thrust blocks

Written by tom fritchman
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to calculate concrete thrust blocks
Thrust blocks are installed to prevent pipes from separating at joints. (replacement of pipes image by Alina Goncharova from

Pipes are used to safely contain and transport materials from one point to another, particularly in the water and sewage venues. In order to move material through pipes, the pipes must be pressurised. It is possible for the sections of pipe to separate under the amount of pressure required to move materials through them. This separation can be avoided with the use of concrete thrust blocks, but you need to know exactly how much area the thrust blocks need to cover.

Skill level:


  1. 1

    Determine the thrust value by multiplying the internal pressure by the square of the outside diameter by the mathematical value π (pi) by one quarter (0.25). The internal pressure should be measured in pounds per square inch (psi).

  2. 2

    Divide the thrust by the allowable soil bearing capacity, measured in pounds per square feet. The allowable soil bearing capacity is a regulated standard charted by your local municipality. It varies depending on the kind of soil, sand or rock that the pipes travel through.

  3. 3

    Multiply the quotient by 1.5. The result is the necessary area that your concrete thrust block must cover, measured in square feet.

Tips and warnings

  • The quotient is the result of dividing one number by another.
  • Check with your local building code authority to determine any special regulations covering concrete thrust blocks.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.