Section 7: Damage from Super Heavy Load Moves
The five typical damages related to super heavy load moves are given as follows:
- Shearing of the pavement surface during turning movements ( Figure 12-4). The figure shows the need to consider road geometry in the super heavy load route evaluation. This damage can be prevented by using trailers with steerable axles. If the mover does not have this equipment, then the engineer can ask that the mover protect the surface at the turn by placing plywood sheets on the surface or laminated mats.
- Rutting or cracking due to overload of the pavement structure. Recent rainfall or poor drainage conditions resulting in weak or wet subgrade or base materials are often associated with structural damage of this type ( Figure 12-5). The figure also shows the need to consider road geometry. The road is narrow, and the outside tires are tracking on the unsurfaced shoulder. Moving of super heavy loads should be avoided on such roads. If there is no other route available, the engineer can have the mover mat the width of road where this trailer is going to track.
- Peeling of fresh seal coats or asphalt concrete pavement overlays ( Figure 12-6 and Figure 12-7). Moves should be avoided on fresh seal coats. If there is no other alternative, the mover can protect the surface by placing plywood sheets.
- Bleeding of seal coats or asphalt concrete surfaces ( Figure 12-8).
- Lateral shear failure at the pavement edge (
Figure 12-9 and
Figure 12-10).
Figure 12-4. Shearing of the pavement surface during turning movements.
Figure 12-5. Rutting or cracking due to overload of the pavement structure. Recent rainfall or poor drainage conditions resulting in weak or wet subgrade or base materials are often associated with structural damage of this type.
Figure 12-6. Peeling of fresh seal coats (1st photo).
Figure 12-7. Peeling of fresh seal coats (2nd photo).
Figure 12-8. Bleeding of seal coats.
Figure 12-9. Lateral shear failure at the pavement edge (1st photo).
Figure 12-10. Lateral shear failure at the pavement edge (2nd photo).
