Appropriate pipe length for numerical modeling of buried pipelines crossing strike-slip faults

In recent decades, due to the increasing use of pipelines to transport a variety of fluids, the need to analyze and evaluate these lines at the crossing faults has increased. In this regard, many numerical studies have been carried out on buried pipes crossing faults. A review of the relevant technical literature indicates that in previous simulations the selected characteristics for creating models were based on researcher's experiences. In other words, the selection of specifications for simulation has been done without scientific support and only for the purpose of simplifying numerical analysis. Therefore, naturally, the numerical results obtained from the finite element analysis can be non-economic or erroneous. On the other hand, common regulations and standards for designing pipelines require special conditions and criteria in this field. For this reason, it was necessary to resolve the ambiguity in this field and select the best dimensional characteristic for modeling buried lines crossing faults. Therefore, during this research, with the help of various numerical models that were built in ABAQUS, using the criteria in common standards and also comparing numerical results with the relations of regulations, appropriate pipe length was determined for pipe modeling. The review of the results shows that considering the length of the pipeline in proportion to the diameter of the pipe or other selected values has no scientific support and the results are not accurate enough. Therefore, researchers in this field should use the unanchored length, to model the longitudinal dimension of the pipe.