Pipeline expansion analyses are calculated using the strain balance method.
The load such as internal pressure, temperature, friction and some effect on residual lay tension will cause to expand at its free end with includes the stresses and force in the pipe wall.
The axial force (Pr) acting on the pipeline is taken as:-
At a distance x, from the pipeline free end (platform end), the soil frictional force (Pfsoil) preventing this movement is represented by the following equations:-
The pipeline end movement occurs up to a point when the expansion force is equivalent to the soil frictional force. This point is called the virtual anchor point. The x value can be solved to obtain virtual anchor point Lexpand1 (hot end) and Lexpand2 (cold end) from the following equations:-