Modelling Backfill Resistance

A series of soil resistance springs, attached to the top of the pipeline, are used to model the uplift resistance of the non-linear backfill.

DMS models accurately the upheaval resistance as pipeline buckles develop and the required download force resisting upward pipe buckling is determined from a soil uplift resistance-displacement curve. Using the determined required download force, the backfill cover height is calculated assuming simple uplift failure mechanism.












                                         >> Upheaval Buckling

Backfill Resistance

The backfill resistance is a function of several soil parameters, including soil density, resistance to shearing and specific cover geometry.

The pipe-soil resistance will depend on the nature of the backfilling process and due to all the uncertainties related to the backfill behavior, the soil properties used to determine the backfill resistance should be taken as lower bound values for the upheaval buckling analysis.

Any assessment that involves jetting or cutting tools may result in significant variation in uplift resistance and mobilization displacement parameters.