Digging an aircraft related deep hole in estuary conditions

Thanks for your posts everyone. The local conditions are soft mud, clay deeper down but no idea at what depth. The size of the hole will be approx 4x4m wide. The depth – possibly as much as 10 meters.

The main issue is keeping the sides of the hole from collapsing. My first choice would be to use wood as it’s cheap, readily available and won’t interfere with the magnetometer.

All depends on the size and depth of the hole you intend digging and the local conditions.

If you just require in wash prevention from back filling the excavation I have seen temporary barriers created from twin rows of of all things 1 tonne bags of sharp sand faced with plastic sheeting used in a river bed allowing work to be achieved inside this alongside a pump to remove seepage, cheap, rapidly installed and easily removed without environmental problems associated with metal piling or earth banking alternatives.
Again with little information on the site conditions and planned depth of excavation it would be hard to define a solution.

There’s a Civil and Structural Engineers in Fareham, called Evans Grant, who do alot of marine work and can also offer diving expertise (used to work for them)

Whitley Project….might be able to help if you want to contact me off-board. E-mail is best.

Apologies for spelling estuary wrongly – not a good start

I have heard of “estuary English” before but not “estuary grammar “

Thanks guys – a cofferdam is very sensible. Anyone with any civil or coastal marine engineering experience – I just need some advice and to run a few ideas by you… if you could pm me that would be great 🙂

Coffer Dam or Caission

This should give you some idea

http://courses.washington.edu/cm420/Lesson4.pdf

Sheet and pump or cassion – so can generalise as well – all depends on ground conditions.

Ross