what makes washboard in dirt roads?

Answer 1

I saw an ineresting bit on TV a few days ago, about just the same thing. The way they explained, it has a lot to do with the vehicles suspension, traction, road density... basically, after the first bump, the suspension is still bouncing and compacts the soil a little. After a lot of traffic, and bounces, the soil becomes compacted into low spots. The next vehicle comes along and bounces/compacts in the same fashion until you have a washboard.

Answer 2

First answer is good, compaction/density ratios and soil mixtures also contribute to a roads durability. Just like building a house. Before you can do the foundation, the soil has to have a certain density, especially on hillsides. If it doesn't meet that standard, then it has to be compacted. Roads, especially dirt roads that aren't maintained, may have different soil density in different spots. The loose soil gets washed or blown away leaving harder soil. Along with the water, traffic, etc. this tends to form the "washboard" effect.

Answer 3

The resonant frequency of suspension combined with braking. When you put on the brakes, the front dives and pushes the tire deeper into the dirt. But the suspension travels farther than it would if the weight on it were static and it rebounds slightly more than necessary, taking weight off the front wheel(s) and allowing the tire to slide a tiny bit, pushing dirt in front of the tire.

When this happens often, you get ripples in the road from tires repeatedly pushing a little dirt at a time over and over.

Answer 4

The roads are unstable, water flows beneath the ground, when vehicles cross over the dirt with the brakes on, it pushes the soil forward. The same happens at interections in the city, the asphalt gets warm, and soft, the cars brake at intersections, again pushing the ashphalt forward. Hope this helps.

Answer 5

airborne dirt and airborne dirt and dirt roads require correct to the comparable velocity of utilising for all travellers with the intention to be mushy and secure. maximum tires are correct to the comparable length. So with the forward rotation those 2 components settle on how far the debris churned up will holiday be for settling back, so each and all of the ripples are correct to the comparable distance aside.

Answer 6

Rain run-off.

Answer 7

Wind and water