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*TZCURVE

Data format:

Up to 6 lines. The first one with two value, the second one is dedicated to calculation parameters with up to 6 values.

NCUR IOD
ITYP F1 F2 F3 F4 F5 F6
Tz1 yt1 Qz1 yq1
Tz2 yt2 Qz2 yq2

Status :

Optional

Purpose :

To define the TZ curve wrt the axial displacement. A TZ curve is related to a soil layer.

Details :

Parameter Description
NCUR Identification number of the curve
IOD IOD=0 : displacement for dynamic curves is defined in meter,
IOD=1, displacement normalized by diameter of element

For static calculation, the friction is calculated along the casing as well as the embedment reaction force at the casing end. We have then 3 configurations depending on the soil characteristic:

If ITYP=0, the soil is characterized by : - F1 : A friction coefficient (Pa) - F2 : A pressure at casing bottom (Pa) - F3 : An initial stiffness (by default, it is defined in *GROUNDPROP)

If ITYP= 1 the soil is coherent and twi parameters are entered: - F1 : Cohesion - F2 : Effective weight (N/m3)

If ITYP=2, the soil is cohesionless, the six requested parameters are: - F1 : Coefficient of lateral earth pressure - F2 : Weight (N/m3) - F3 : Friction angle between the soil and pile wall (°) - F4 : Dimensionless bearing capacity factor - F5 : maximum unit skin friction capacity (limit the unit skin friction capacity if greater than 0) - F6 : maximum unit end bearing capacity (limit the unit end bearing capacity if greater than 0)

In dynamic, either the friction is still used or a linear spring can be defined.

Tz1,... For dynamic calculation, 2 curves are input to model a non-linear spring: - The first one represents the spring along the casing (Tz1,yt1) - The second one the spring at the casing end (Qz1,yq1). To represent these non-linear curves , several couples of points must be defined.

Note

All the coefficients are in Pa. You have to create as many *TZCURVE keywords as soil layers; i.e. one curve for each layer.

Example :

  • For static calculation

*TZCURVE
1
0. 1e4 1.0

  • For dynamic calculation

*TZCURVE 1
0 1e4 0.
0.0 0.0 0.0 0.0
1e5 1.0 0.0 10.0
1e6 10.0 -1 -1
1e7 100.0 -1 -1