As a kid on the beach, did you ever pat a lump of moist sand until it went runny and turned to quicksand? Well if you did you were unwittingly conducting experiments into the liquefaction of granular soil types through cyclic loading (and your mum thought you were just making a mess!).
Weird how a bit of vibration can turn something solid into something liquid like that. In fact I spent a good part of the final year of my degree course in a geotechnical lab studying this very subject; so I could explain this phenomena in a few thousand words if you’d like?
No, thought not.
So why am I thinking about this today? Well just occasionally these weird bits of scientific research find an everyday example, such as the story I was told today.
Imagine if you will, a construction site with pretty little stream that passes to its side. Being responsible contractors, they had created a bund of hay bales, to ensure that any slurry spilt on site in the course of the construction work, wouldn’t enter the stream.
All very innocent and unremarkable until you add two extra ingredients:
a) an area of ground that has experienced liquefaction as a result of the vibrations from the construction plant, and
b) a greedy horse that decides to break out of its nearby paddock and make a bee-line for the hay bales
I’m told it’s not easy to extract a horse that has sunk up to its back into the ground…
Of course we shouldn’t be too surprised that even this wasn’t too much of a challenge for the local fire and rescue service and the horse was duly rescued unharmed.
So a happy ending…which is just as well considering how funny we’re finding this.
Love to see their revised risk assessment though!
