PH model: Surface heave upon excavation

FLAC3D
1

Hello,
In the example “Dewatered Construction of a Braced Excavation”:
https://docs.itascacg.com/flac3d700/flac3d/zonesel/test3d/ExampleApplications/BracedExcavation/BracedExcavation.html?node3606
The surface settlement profile:

1024×768 12.4 KB

presents 5-7mm heave on 30-80m from the excavation wall. Is this the expected behaviour in reality or just a specificity of the constitutive model ?
Thanks

2

Hello,

The Ph model with small-strain stiffness gives the closest to what is observed on the field : limited upward displacement at the ground far from the wall.

1 Like
3

The model will show this also without Dewatering. Even bigger magnitudes.

We did a lot of extreme projects, braced excavation up to 20-30m depth, 20m Dewatering, in old urban places.
You not measure mm.

4

Interesting: at the example you attached the wall modeled as liner, and not as a beam.