Buoyancy Force for Buried Steel Pipe

Buried Pipe Design - Google Books Result

Excellent reference!

GA

Stewie

My sentiments entirely. Very sage.

See Chapter 7-Pipeline_Design and Construction-A_Practical_Approach (2nd_Ed)

The result is buoyancy force is negative.

Did it mean that pipe and its content are naturally sink?

YES!

The wall thickness of concrete pipe in the USA is t=D/12+1. D is in inches and the resulting answer t is also in inches. Therefore, the volume of water displaced by a pipe per foot if pipe is as follows:

V=((2t+D)/12)^2*pi/4. Therefore the bouyancy force B is B = 62.4*V.

62.4 is the weight of water in pounds per cubic foot and the result force up is in pounds.

The weight of concrete is about 145 pounds per cubic foot. The weight of a concrete pipe is therefore a function of its diameter. W=(D/12+1)(13/12*D+1)pi(145/144).

You will see that most pipe will want to float if there is no earth on top of it. However, if the pipe is buried, the weight of the earth is almost always sufficient to hold the pipe down, unless it is a large diameter pipe with shallow cover. Therefore, you should check this.

Also, manholes and inlets will want to float. You will need to check these to make sure they are anchored properly.

I don't think the pipe itself is concrete: I think the OP (original poster), wants to know if he needs additional concrete weights to hold down a steel pipe.

The goal of topic are:

For Bouyancy force negative, Did it mean the pipe is being sink? (yes)

Does concrete weight any standardisation??

From article "Buried Pipe Design" any standard of safety design. The downward force should be at least 2 time the uplift force...is 2 time (safety factor) enough? did anyone have design with safety factor 2? how is it going so far?

The pipe is carbon steel (not concrete)

i want to calculate the buoyancy force during pulling a steel pipe 42 inch under sues canal using the horizontal directional drilling.