Pakistani pile driver

[braumeister]

Something to amuse the engineers in the audience.

A short video of a Pakistani pile driving construction technique. Notice that the pile driving only becomes effective when the extra man jumps on. Very finely tuned! The chant is also catchy!

Now, let's analyze the engineering here:

6 men x 180 lbs = 1800 lbs static force. Jumping up and down will create a 3 times dynamic effect = 3240 lbs/jump = 1.6 ton thumps. If the pile is tapered to 2 in x 2 in, cross section at the tip = 4 sq. in.

So, dynamic pressure/thump at pile tip = 3240/4 = 800 psi.

"Add a man" feature will increase to 950 psi, so buy the option!

Increase the chant and dynamic force goes up to 5 times to bring max. pressure/thump to 1600 psi for a 7 man team.

Quite good and will penetrate hard clay and sandy soil but not hard rock! Pretty ingenious.

The foreman is the guy on the tambourine.

And I'm sure that at least one of you will reanalyze this and correct the calculation errors!

Pakistani pile driver

 

[Sue J]

That was great! But I cringe at seeing bare feet at a construction site.

 

[audreyh1]

Very cool!

 

[CardsFan]

That was great! But I cringe at seeing bare feet at a construction site.

In Singapore 15-20 years ago the footing foundation excavation crew was primarily older women, wearing sandals at most, swinging pick axes and shoveling the dirt into woven baskets that were carried to the disposal area.

Not exactly OSHA approved .

 

[ls99]

Gotta love improvisation.

Oh yeah OSHA: mandated backup noise makers on all commercial and industrial moving equimpment. Then mandated hearing protection in the area to prevent hearing loss from all the racket. Then had to increase noise level to be able to hear the backup alarms while wearing hearing protection.

I am waiting for seatbelt laws for motorcycles.

 

[ls99]

That was great! But I cringe at seeing bare feet at a construction site.

Check out some youtube videos of shipbreaking in Bangladesh.

 

[NW-Bound]

Something to amuse the engineers in the audience.

A short video of a Pakistani pile driving construction technique. Notice that the pile driving only becomes effective when the extra man jumps on. Very finely tuned! The chant is also catchy!
...

Very interesting! Now, about the computations...

Caveat: I am not a civil engineer.

Is the 3x or 5x force-multiplying factor in bouncing a reasonable value to use? Sounds reasonable, but I do not really know. A quick search on the Web found this scholarly article on the dynamics of squat jumps. It causes a force 3 times the weight of the jumper. Bouncing on one's legs probably would have the same effect, but of much shorter impulses. It's amazing that it is still effective and sinks the pile in the matter of seconds.

See: http://www.brunel.ac.uk/~spstnpl/Publications/VerticalJump(Linthorne).pdf

One question of curiosity: what do the piles eventually support and how much does that weigh? If it takes only a few thousand pounds to drive each of them into the ground, how much margin is there to keep them from sinking further when structures are built on top?

PS. It is obvious that the last guy who hopped on increased the force enough to exceed the ground resistance. These guys had worked this soil before, so knew what it took to do the job.

 

[NW-Bound]

Eh, the video in the OP was labeled "Human Pile Driving In Thailand". It's not in Pakistan.

Here's another similar one. I don't think these guys weigh 180 lbs each.

 

[ownyourfuture]

Gotta love improvisation.

Oh yeah OSHA: mandated backup noise makers on all commercial and industrial moving equimpment. Then mandated hearing protection in the area to prevent hearing loss from all the racket. Then had to increase noise level to be able to hear the backup alarms while wearing hearing protection.

I am waiting for seatbelt laws for motorcycles.

I'm with you 100% 99!
OSHA, necessary at its inception, but now just trying to justify their existence with more & more ridiculous rules.