A
Anonymous
Guest
Not really my area, but I think that I have a plausible explanation though:
The top layer of the road is pretty resilient due to the nature of the asphalt. But since many roads are made up from 2 slabs (due to construction techniques) there is a joint between these slabs in the middle.
When the earthquake struck then the most obvious failing point would be that joint, and the underlying material just followed the crack formed in the asphalt. Since the top layer keeps the underlying material (in this case sand, usually gravel) in place.
Another road:
I hope that any of this made any sense
The top layer of the road is pretty resilient due to the nature of the asphalt. But since many roads are made up from 2 slabs (due to construction techniques) there is a joint between these slabs in the middle.
When the earthquake struck then the most obvious failing point would be that joint, and the underlying material just followed the crack formed in the asphalt. Since the top layer keeps the underlying material (in this case sand, usually gravel) in place.
Another road:
I hope that any of this made any sense