rats can make underground holes..so long and never collapsed.
How??? Compared to human train track tunnel boring works that need a lot of calculations and supporting works ...
2006-10-08 16:39:54 · 5 answers · asked by Steven A 1 in Science & Mathematics ➔ Engineering
Rat holes are small diameter holes, not far underground in soil.
If they do collapse, what falls on the rat is not heavy enough to kill it.
Human built train tunnels are large diameter holes, further underground through rock. If they collapse, they kill people.
2006-10-08 17:30:13 · answer #1 · answered by Stewart H 4 · 0⤊ 0⤋
Two reasons:
1. Rat holes are smaller in diameter, so the change in void space isn't as great.
2. Nobody cares or notices when a rat hole collapses, there is no loss of human life and the media doesn't have a frenzy over the event.
2006-10-09 03:34:35 · answer #2 · answered by Jeffrey S 6 · 0⤊ 0⤋
It is a simple matter of insurance. Rats do not need to worry about professional indemnity insurance should something go wrong with the design, the construction or the operation of the tunnel. There are also no financial, criminal or other similar penalities for breaches of the contract. So for rats it is a simple matter of just "dig in and under".
2006-10-08 17:35:10 · answer #3 · answered by cruezr 1 · 0⤊ 0⤋
Two reasons: ratholes are not far underground, so soil pressures are not high; ratholes are not nearly as large as people tunnels, so the radius of curvature is much lower and there is more compression to keep the soil in place.
2006-10-08 16:43:52 · answer #4 · answered by Anonymous · 2⤊ 0⤋
I agree with the answer above, but also, are you sure rat holes never collapse?
2006-10-08 17:19:43 · answer #5 · answered by Game Theorist 2 · 0⤊ 0⤋