Elaboration of the three lateral soil characteristics into a general model
In three main lateral directions, upward, downward and sideward (both directions), the soil stiffness and ultimate soil reaction are determined based on the well known failure models. However, a general 3D pipeline configuration will displace in various directions in between the main directions.
In order to achieve, that the soil reaction is always opposite the displacement direction of the pipeline, a relation between the soil stiffnesses in these main directions and the same between the ultimate soil reactions has been developed.
Between successive values of the soil stiffness an elliptic relationships are taken as has been done for the ultimate soil reactions.
In the iteration process on the soil reaction to fulfil the R-d curve, the curve is each time adapted to the displacement direction found in the previous iteration step.
PipelineSoilModel, last changed: 14/09/2016