I'm looking for some fairly urgent advice from you excellent people at LJN:
We begun excavations for a build last week in a (completed) housing estate that is around 5 years old: the ground conditions were already damp and part of our remit is to install suitable drainage.
On Friday (day 2) both 1T dumper and 1.5T digger got stuck in around 2-3ft of very soft ground (heavy saturated clay - pulls your boots off stuff) which covers around half of the site area. It took 6 hours today to free the machines today after an attempt to use rescue machines on Saturday morning.
The rain has been torrential almost non-stop since around 1am last night and the site conditions have further deteriorated, but we need to finish the project within 6 weeks before the anticpated winter weather arrives at the end of November.
Has anybody used cost effective soil stabilisation techniques successfully and if so what were they?
Assuming that enough time has lapsed since the housebuilder completed the estate to negate their liability for remediation - I have been reading about application of lime, cements, low impact chemical slurries that firm the ground substantially (lime having been used for thousands of years for this purpose) but most evidence of modern application seem to be for large scale construction projects - I cannot find any instances of small (residential) site application. Can anybody here help with tested advice or point us in the right direction?
Thanks, Nicky
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Would this not cause problems with draingage down the line or is that not going to be a problem>?
Perhaps getting the client to invest in a land-drain or soakaway would be a good idea, and help get the rest of the job done!
Did something similar a couple of years ago, site was not rotovated (dug down & found the normal building site debris - not conducive to good drainage) or levelled out by builder in preparation for laying of turf we sunk several soakaways,used perforated drainpipe in order to take the problem away , rotovated & levelled off but in the end it was down to the builder to make good the drainage which they tied into the rainwater drains connecting into pipework we had installed don't know if that would be an option for you, when they put machinery on the site the machines sunk down same as what happened with yourself .
Appreciate the input so far folks:
Ply sheets not practical at this stage (initial excavations and levelling prior to drainage) although we do have traction boards. No "soft spots" as such since there are no significant "firm spots".
Ground is so saturated that any drainage channel attempts are quickly filled with "soup" and the walls fail within minutes.
Soakaways and overflows to main storm outlet for house are all part of the plan (no SUDS requirements as yet in Scotland) but we need a solution to get us to the stage where we can actually do this. For now it is hopeless.
Waiting for the frosts would help with this stage but then prevent us from the main part of the build.
Has anybody come across the lime or cement methods in residential situations like this? I was hoping some of the larger contractors with commercial experience would be able to offer some wisdom on these approaches: a Youtube search for "lime stabilisation" will provide some videos of the treatments i refer to.
Hi Nicky,
There is a product out there called DryAdd that dries muck up.
I havent used it myself and dont know the costs involved.
you can get it from Mudtech Ltd - Morrison Mud Division 0121 360 7669
probably worth a call to see if they can help.