Pipe Bulkwall Design

[GMCM]

I am designing a bulkwall for a 42'' hdpe pipe. The pipe is to be abandoned in place via grout fill, hence the need for a bulkwall. Anyone know of any sizing equations and/or standards that I should be aware of? I have been looking at bulkwall design standards from the US Bureau of Mines Information, but this is likely not the best reference for information in my case. Appreciate the help.

 

[amlinerrichard]

Just build a wall of concrete blocks and fill SLOWLY. Monitor the bulkhead as the pipe fills. what kind of grout are you using?

 

[GMCM]

My concern is the masonry not adhering to the HDPE surface. The fill is required to meet 300psi (Union Pacific requirement) so it will likely be a clsm mix with a water reducer. The longest flow section is about 500'.

 

[amlinerrichard]

Attach a curved steel angle all around the HDPE. Shotcrete the angle to the block. Maybe add a few #4 rebar before the shotcrete.

 

[cvg]

you will need a very flowable grout to completely fill 500 feet. Using internal grout tubes (I believe they were 2 inch), we had difficulty pumping clsm 150 feet. Mainly because it was too stiff. and superplasticizer doesn't help that much. You might consider a cellular concrete grout instead. NRCS has a good spec for it. assuming you have vent holes, you should be able to keep pressure against the plugs low (assuming your pipe is relatively flat)

 

[GMCM]

I considered cellular clsm. I am stuck with Union Pacific's requirement of 300psi though (pipeline is in a UP ROW). I don't think 300psi is achievable with cellular.

 

[miningman]

I'm curious here. What is clsm??. Is this a tunnel that is being sealed and abandoned?? If so I have extensive experience. We used 8x8 timbers with 6X6 bracing and 2x 6/8 for the formwork.On one job we pumped 800 feet with minimal difficulty

 

[GMCM]

controlled low strength material, or "flowable fill". Yes it is for the abandonment of a 42'' hdpe sewer line.

 

[cvg]

I have test reports from a project where the cellular concrete reached 1,700 psi at 28 days. so 300 psi should be a piece of cake

 

[GMCM]

amlinerrichard can you provide more detail about the shotcrete method you mentioned?

 

[amlinerrichard]

shotcrete is a sprayed on concrete. Cement sand and pea rock. Call a couple contractors that do that work.