Anchor openings in diaphragm wall

[Laaitie]

Hi, we are considering it to construct a diaphragm wall for a 12m deep basement in reclaimed sands with a relatively high water table in Cape Town. I know there are various products to seal the anchor opening after instalation, but how do I minimise water ingress during instalation of the anchor?

 

[BigHarvey]

It all depends on the head of water and permeability . In the worst case you use a "sas" , see photo attached. In South Africa , you can contact these people, they have the experience to do it

DURA Soletanche Bachy
104 Aeroton Road - Aeroton Extension 2
GAUTENG, South Africa
Adresse Postale :
PO Box 38041
Booysens 2016
Gauteng, RSA
SOUTH AFRICA
Tél. : +27 11 226 84 00
Fax : +27 11 494 16 04

gauteng@durasb.co.za

http://www.durasb.co.za/

Contacts :

Patrick IMBERT
patrick.imbert@soletanche-bachy.com

 

[Erdbau]

You also need to be careful of the sands running in during the installation, especially if the sands are fine and clean. You may need to use drilling collars (I'm assuming that's what that "sas" is, Big Harvey?). Definitely talk with the contractors, and be careful, especially if there are adjacent properties. You can get yourself into a lot of trouble with sands below the water table.

 

[PEinc]

Nicholson Construction did the new tieback anchors through the diaphragm walls at the World Trade Center site in New York. They used drill collars through the wall to control water seepage and loss of soil. Nicholson is a US subsidiary of Soletanche Bachy. Therefore, your contractor should know what to do.

http://www.PeirceEngineering.com

 

[PSlem]

Since anchors probably at 45* you might be able to just extend pipes up and out to terminate above WT and drill through them with an ODEX system to minimize flushing loss.