The effect of variation of soil conditions along the pipeline in the fault-crossing zone

The effect of special (loose sand) backfill segment length on the pipeline response under strike-slip and normal-slip fault actions is studied. It is shown that the extension of the special backfill length has an advantageous effect in case of substantial axial fault displacement component. In this case, the reduction of soil constraining effect on a larger distance substantially reduces the maximal tensile strains in the pipeline. In contrast, under bending-dominant behavior of the pipeline, the elongation of the special backfill zone has no positive effect on the maximal strains.