Calculating pressure on an embedded pipe in vertical plane

[CWoodhouse]

I have a problem and it consists on placing a square PVC pipe vertically in a trench and surrounding it in concrete, I would like to know how would I calculate the sufficient wall thickness of this pipe and the maximum depth of the trench etc before the pipe would yield to the surrounding pressure of the concrete. I am not sure how the pressure will be distributed within the walls of the trench and how much of concrete head pressure will be acting on the pipe.

Can anyone help?

 

[Travis_King]

Does the pvc pipe have to be empty of concrete to the bottom? If you allow the bottom to fill up some with concrete, you won't have to worry too much about it.

 

[CWoodhouse]

Yes the pipe would need to be sealed, causing a pressure difference.

 

[RocketSci5KN]

Option A: use a cylindrical 'pipe', which is much easier to find, cheaper, and will handle pressures much better.

Option B: Fill either 'pipe' with any fluid having a density at or above the concrete, such as something similar to drillers mud, and pump out later. That way, no differential pressures.

Option C: Obtain the working pressure for the PVC schedule proposed, and derate it by a factor of 3 or so since pipes perform worse for external pressures than internal. Calculate the concrete pressure at the bottom, knowing its density is about 2.4gm/cc. Limit concrete height to what would give you 1/3 of the internal pipe rating.

Option D: combine option C with a water fill to get some internal pressure.

 

[alphy]

To calculate the pressure on an embedded pipe in a vertical plane, you will need to consider several factors such as the depth of the trench, the type and density of the surrounding soil, and the weight and density of the concrete used. This can be done using mathematical equations and principles of fluid mechanics.

First, you will need to determine the maximum depth of the trench based on the type of soil and the desired stability of the pipe. The deeper the trench, the more weight and pressure the pipe will be subjected to.

Next, you will need to calculate the weight of the concrete that will be surrounding the pipe. This can be done by multiplying the density of the concrete by the volume of concrete surrounding the pipe.

Once you have these values, you can use the principle of buoyancy to determine the pressure exerted on the pipe by the surrounding concrete. This pressure will be distributed evenly on the walls of the pipe, so you can calculate the required wall thickness by considering the maximum allowable stress for the pipe material.

It is also important to consider any additional factors that may affect the pressure on the pipe, such as temperature changes or external forces.

Overall, the calculation of pressure on an embedded pipe in a vertical plane can be complex and it is recommended to consult with a structural engineer or other experienced professional for accurate and safe results.