Specification of maximum horizontal soil reaction along pipeline axis (Input Table)
Through the input data table RH the maximum horizontal soil reaction 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. Coordinates of successive data table lines shall have increasing values.
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 factor CFH additional ultimate lateral soil reaction is added to the specified initial resistance RH equal to CFH*R-LAT(vertical component downward). In that case RH is adjusted in each soil iteration. Applying a CFH value >0 will increase the required number of iterations to fulfil the iteration criteria. The CFH factor will be useful especially for on-bottom pipelines. In that case the RH value represents the lateral resistance from the 'imprint' of the pipeline in the bottom.
UNCF factor is applicable only on the specified RH value.
H320172, last changed: 2008-07-21