| Method | Advantages | Disadvantages |
|---|---|---|
| Reduce the operating pressure of the pipeline. | Provides a direct reduction of the hoop stress due to internal pressure. This reduction allows for additional circumferential stress due to equipment loads | – Reduces the beneficial effect of internal pressure on the pipe circumferential bending stresses due to fill and traffic loads. – Could reduce the overall capacity of the pipeline and therefore should not be considered as a long term fix. |
| Limit surface pressures under vehicles (e.g., using floatation tires or caterpillar tracks) | Spreads the surface load over a larger area and reduces the overall load to the pipe. | Depends on equipment. May not be possible or too costly to implement |
| Consider the beneficial effect of lateral soil restraint on circumferential stress | Has effect similar to pressure stiffening | Requires estimates of soil stiffness parameter, Eā |
| Provide additional soil fill over the pipeline in the vicinity of the crossing | Reduces circumferential stresses due to traffic loads. | Increases circumferential stresses due to fill loads. |
| Deploy steel plates over the crossing | Easy to install. | Flexibility of steel plates can result in bending of the plate with a corresponding reduction in loaded footprint. Need to consider required thickness. |
| Deploy timber mats over the crossing area | Provides large loading footprint. Relatively easy to deploy. | Flexibility of timber mats can result in bending of the mats with a corresponding reduction in loaded footprint. |
| Construct a concrete slab with steel reinforcement over the crossing area | Provides large loading footprint. Slab can provide high bending stiffness. | Relatively expensive. Usually reserved for permanent crossings. Slab limits access to pipeline for inspections and repairs. |
| Construct a short bridge crossing over the pipeline | Completely uncouples the traffic loading from the buried pipeline. | – Requires construction of foundation structures. – Expensive to construct. Usually reserved for permanent crossings. – Bridge structure may limit access to pipeline for inspections and repairs. |
| Relocate the pipeline | Removes pipeline from loaded area. | – Expensive to construct. – Usually considered only as a last resort. |
| Lower pipeline | Reduces circumferential stresses due to traffic loads. | – Expensive to perform. – Usually considered only as a last resort. |
Surface Load Mitigation Measures – Best Practice
Updated on September 26, 2023