3D Finite Element Seismic Simulation of Steel Pipelines Embedded in Different Backfills

Seismic events may drastically damage buried pipelines affecting economy and public safety. ASCE provides design guidelines for analysis of buried pipelines under different seismic loads. This study evaluated performance of steel pipelines under seismic loads when embedded in different backfills using a 3D finite-element model (FEM). Results were compared with ASCE design guidelines and the effects of different model parameters were evaluated. These parameters included soil-pipe interface, boundary conditions, and model dimensions. After setting the model parameters to match the maximum pipe stress predicted by ASCE design guidelines, effect of using a controlled low strength material (CLSM), in lieu of compacted soil, as a backfill material was evaluated. The same model was also used to evaluate the effect of having a fixed connection at one end of the pipeline since ASCE design guidelines are based on the assumption of infinitely long pipelines. It was concluded that a 3D FEM model with carefully selected parameters can match the ASCE design guidelines and further be used to test the effect of various scenarios which cannot be evaluated using these guidelines.