Try to evaluate the leaking of a grout in a soil

[Geotektonik]

Hello fellow geotechnicians!

I am about to install inclinometers in a soil made up of 3 layers : lime/sand/clay(from bottom to top), and I would like to evaluate the grout leak which is going to happen during the injection. Do you have any suggestion about a formula or a model I can use (I know the main geotechnical properties of this soil)?

Thank you very much for any idea!

Best regards

 

[oldestguy]

In order to get a response, I'd suggest you describe your project some. Attaching a sketch may help. The clearer you are, the better the response.

 

[Geotektonik]

Hi, thank you for your advice!

I don't have a sketch right now, but I can describe the project. It is a typical londonian soil :

Clay
___________________
Clay & sand
variations
___________________
Limestone

I am installing inclinometers (nearly 100m depth) and I am trying to estimate the quantity of grout I must use.

The grout composition I am using is cement(94lb)/water(25 us gallons)/bentonite(39lb).

The borehole is 10cm wide, 100m deep, and the casing is 7cmm wide. For the moment, I am considering that the amount of grout leaking in the ground is nearly equal to the volume of the casing. It means I plan on a grout volume equal to:
0.0025 square m x pi x 100m = 785 L

I am sure there is some better way to evaluate this quantity, by calculating the volume of grout leaking in the ground.
I was thinking that maybe that Lugon test formulas could help me, but I didn't find anything useful...


Any idea?

 

[Prepakt1]

The only way to evaluate is to drill some test holes. Grouting is not amenable to accurate estimating of quantities required. You try it, see whats working. If your using too much material change grouts, add expanders change methods . You have to decide on the job whats appropriate as you progress by monitoring flow and pressures at the pump.

Intrusion Prepakt /marineconcrete.com

 

[Geotektonik]

All right, so there is no theoretical model which allows to evaluate that leaking, only in situ experiment?

Thank you very much for your answer Prepakt1.