Dec 2014, AutoPIPE V8i 09.06.01.10
Do we have to define the soil properties after the La (i.e., in Zone 3)?
If yes, what will be the max soil spacing after the virtual anchor length (i.e., in zone 3)?
Please see the following AutoPIPE help section:
Help > Contents> Contents Tab> Reference Information> PipeSOIL> Model Discretization> Figure D-1: Comparison of a buried pipeline with a bend to an infinite beam on a continuous elastic foundation.
All piping in AutoPIPE is supported by Pipe supports or Soil points, otherwise the pipe is free spanning.
Theoretically, an anchor node point can be modeled anywhere in Zone 3 and no additional piping will need to be modeled. Another words, as mentioned in the online help, piping system can be terminated and anchor at La distance from the elbow (i.e. Zone 3).
However, the user can choose to model the entire piping system past the La dimension by adding additional node points and soil points along the pipe as required.
What soil spacing should be used in zone 3? As an estimate, suggest using the same soil spacing as mentioned for Zone 2, try increasing this spacing while reviewing the results to see if they are affected. The final maximum soil spacing in zone 3 becomes an engineering judgement.
Model Soil Properties with Soil Calculator