AbstractControlled low-strength material (CLSM) has been widely used for pipe backfilling applications with several advantages, as described in detail in numerous documents. Our previous study indicated that buried pipelines backfilled with CLSM show better performance when subject to seismic wave propagation. In this study, a nonlinear three-dimensional finite-element (FE) model was used to evaluate the seismic performance of buried steel pipe backfilled with CLSM when subject to a reverse-slip fault. The developed FE model results were validated by full-scale experimental data obtained by others from the available literature. After FE model validation, the developed FE model was utilized to evaluate the effect of various FE model parameters on pipe seismic performance, including CLSM trench continuity through the fault plane, CLSM–pipe friction coefficient, backfill material shear strength and Young’s modulus, and pipe diameter-to-thickness ratio. The seismic performance of pipe embedded in CLSM backfills was compared to pipe embedded in soil backfills. Results from these model parametric studies indicated that the pipe with CLSM backfill did not show better seismic performance than soil backfill due to the higher material stiffness. The research findings from the previous study by the authors in conjunction with the findings from this study provide a more complete understanding of pipe seismic performance backfilled with CLSM in seismic-prone areas.