Longitudinal soil friction [F]

Specification of maximum longitudinal soil friction along pipeline axis (Input Table)

Table description:

Through the input data table F the maximum longitudinal soil friction along the pipeline axis is provided to the soil model.

The soil parameter is provided as a polygon data line projected on one of the available coordinate axes by means of reference points. The value of the soil parameter is attached to each pipeline node by relating the coordinate of the node to the polygon data line and interpolating the parameter values at the adjacent reference points. The values given for the soil parameter are interpreted as 'mean' values. These values are altered by means of the uncertainty factor UNCF according to the data provided in the input data table UNCER.

In case a stochastic analysis is being made, the UNCF values are interpreted as standard deviations.

The variation parameter VARAR defines a 'band' around the soil parameter value as it is going to be used in calculations, in order to allow for iteration inaccuracy required by the computation model taking into account the non-linear character of the soil model.

Through the friction factors CFA1 and CFA2 additional ultimate friction is added to the specified initial friction F equal to CFA*R-LAT. In that case F is adjusted in each soil iteration. Applying a CFA value > 0 will increase the required number of iterations to fulfill the iteration criteria.

UNCF factor is applicable only on the specified F value.


H320132, last changed: 2008-07-21

See also:

Data description/conditions

Table error description

Design Function 3.2