Earth retaining structure 3

[babun1]

I am modelling a deep excavation with plaxis soil hardening. Heaving is coming much. I am not being

 

[jdonville]

Please complete your question. Providing more details can only be helpful to those trying to help you.

 

[babun1]

I am dealing with an excavation of 24m deep and 12m wide with secant pile wall. top layers are mostly clay with cu varying between 20-50 kpa and below 20m is silty sand. Excavation analysis is giving a heave of 100mm.

 

[PEinc]

Redesign the secant pile wall. It doesn't go deep enough to prevent heave and it probably will need to be a stronger wall as it gets deeper.

http://www.PeirceEngineering.com

 

[HENRYZAU]

use Generalized Hardening Soil Model - links:

https://www.plaxis.com/support/models/udsm-generalized-hardening-soil-model/

 

[EireChch]

100mm of heave in a 24m deep excavation sounds about right?! Although the softer the clay is the less heave you should get.

You also have to use judgement with your results. Plaxis will give you a decent amount of heave even if you have a loose sand. Reset displacements to zero......

 

[babun1]

Thank all for useful suggestion. I have checked we don't have GHS model in plaxis. In that is there any procedure to increase the stiffness of the bottom soil to have a more realistic picture.

 

[HENRYZAU]

To OP, HSS model would improve the prediction on base heave compared to HS model.