Hi, stumbled across the forum while running some online searches so thought I would share my latest project! 

Just wondering what experience anyone out there has with A) Pumping concrete across a distance of 1.3km or thereabouts, B) Pumping concrete into a tunnel and C) First Stage Concrete pours.

We are pouring First Stage Concrete Track Slab at 645mm (chord size) in a 1.3km tunnel, being a tunnel there are canted sections etc, which is a huge problem in itself. We need the concrete wet enough to be able to flow through the 5" pipe but 'dry' enough not to fall into the canted section of the tunnel. The biggest cant of the tunnel is 145mm, therefore creating an approximate slope of 300mm across a span of 3.9m! 

The finish of the track slab is to be done with screed rails due to the tolerance being +-5mm, so accuracy is also a must! We are proposing on using a gantry on wheels that runs on the tunnel walls meaning we wont actually come into contact with the concrete. The screed rails will be taken out as we go along, but we have been discussing the option of having a rail that is above the pour and to use a 'rebated' tamp to get the final level, but with the tolerance we aren't sure if this would work that well.

We are aiming at pouring linear 60m a day, pouring 5 days a week, looking at an approximate figure of 130m3 a day and starting at 8am with a view to pour for approximately 6 hours. The pump we are using is a Putzmeister Static NW636 (BSA 2110D).

We have a plan etc and plan to start the pour on 7th August, so any ideas that can be posted or discussed before then would be nice, and maybe we can implement something into the tunnel!

Feel free to contact me via email on 'lewis@kellyformwork.co.uk'

Regards,

Lewis Turnbull

why not just use a slip form for the tunnel, and pump self consolidating concrete. use a diversion valve at end to blow the pipe out with a go devil, devil catcher and air

Yeah water wash would be safer lol. i did 2500ft 5 inch like that but 1.3km would be better to pump water

I agree with Dipstick. You should use water to blow this out. I pumped quite a distance for tunnel work. The problem I had was the actual tunnel lining mix was not pump friendly due to the microfiber that they put in the mix. I could pour any of the other structural mixes without a problem. We poured wet but with a high strength mix so we could get our breaks in 12 hours. The forms were stripped and reset and another pour happened in 24 hours from pouring the last form. It was quite a challenge and the mix design was not up to it.

I am not the pump driver, I am the project manager on the job and we have been discussing the various options on how to go about pouring the tunnel slab etc etc, and with drivers seeing so many different types of concrete pours I thought I could get some ideas/advice on here!

After more discussions this week I have now established how we are cleaning the line. We are proposing to empty the line of concrete but put a 'pig' with 1 or 2 balls behind the concrete and then push with water. The concrete in the line then completes the pour and the water can be drawn back through the pipe and pump on the pump side and stored/disposed of.

My concrete pump knowledge isnt very extensive so thats about as best as I can explain!

Photo 1 - This is taken from the mouth of the tunnel, this is intended to be poured via mobile pump at this stage, the pour was 60m (linear) and we will use mobile pump for around 4-6 pours, and then we will proceed with the static pump method I mentioned previously.

Photo 2 - This is the contents of the pour, screed rails on the outside with a drainage pipe and chairs/mesh reinforcement in the middle. Our biggest concern is the level with our +-5mm tolerance, so we are hoping the rails do their job!

Photo 3/4 - Just some more snaps of the pour, its the first time we as a company have tried anything like this, and with the tolerance needed we really want to get this right, and at the first time of asking!

I have seen Danicon A/S's work and they are impressive with the scope of extreme pumping that they do. I have also communicated with them via email and they are very knowledgable. I can also help with some questions and I have sent you my email in a private message. Many things can and will go wrong during long line pours.

Do you supply the line only or would you also provide the labour?

Lewis

Just a couple of photos that show our line installed to the wall, and the line that is running vertically from above the tunnel entrance. Also the huge static pumps we are using. Nice to see our setup isn't too different from yours Daniel ;)

One of my co workers who is part time works underground at a potash mine when he isnt pumping for us. At the surface They have 5inch pipe going 3200feet vertical to mine level. At this point the line turns horizontal and continues for up to 6000ft. he has cell phone video driving in a 4*4 vehicle that goes all the way to the end of the line. he is driving fast and the video is 4min long. They fill caverns and holes with endless fillcrete. This is all done with the head pressure from the 3200ft vertical drop. they run a small line pump thats it. its pretty nuts. i still think the danicon video is the craziest i have seen yet. but this mine thing is pretty cool. i will try to get the video from him.

So far so good! No blockages at all, everything running smoothly for the minute and I hope it stays this way! :)