Frost Depth and Temporary Bridge Abutments

[anominal]

Here's a quick one.

I've "designed" temporary bridge abutments (abutments) for a temporary bridge (bridge) - please see attached. The abutment is made of concrete deadmen and timber crane mats.

The bridge will be in service for eight months max, starting this October. It services less than 10 residents. It is on a private driveway with no outlet. It is near a major river that tends to flood in the spring, the whole bridge may be underwater for a little.

Is frost depth a consideration for this temporary structure? If I neglect it and put deadmen on grade, what's the worst that will happen?

One last thought... scour.

 

[wiktor]

No, frost is not considered for temporary structures. The worst what could happen will be slight heave of the structure.
Scour should be considered, as the bridge could be undermined when flodded.
May be place some stone ballast around the supports to prevent erosion. The size of the stones shall be based on the expected stream velocity.