Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Water Bag Load Testing

[Subject Prev][Subject Next][Thread Prev][Thread Next]

And don't stand underneath when test loading.


I test loaded a railroad flat car bridge over a creek using a fully loaded gravel truck.  I was under the bridge with a level to read the defllection (and to prove I believed in my design so much that  I was unafraid to be under it when loading - a level of confidence that every structural engineer must have or at least convince others that he has).  With much creaking and groaning of the bridge, the gravel truck approached the critical loading position.  I measured the deflection, which of course kept increasing up to that final truck position.  The truck driver halted at the pre-arranged location                  and let off his air brakes with that big SCREECH-WHOOSH.  After I regained my composure, I stepped out from under the bridge and kept my backside away from everbody so they couldn't see I messed my pants.


Bob Garner, S.E.


From: Harold Sprague [mailto:spraguehope(--nospam--at)]
Sent: Monday, November 17, 2008 8:58 AM
To: seaint(--nospam--at)
Subject: RE: Water Bag Load Testing


Please do not forget shoring for safety especially if you suspect a shear failure.  The shoring is also a good place to mount gauges.  The smaller the gap the smaller any impact.  Bending is not generally as much of a potential catastrophic failure, but calculate anticipated deflections.  If the deflections go off the chart, something is wrong and the test should be terminated. 

Regards, Harold Sprague

> Date: Fri, 14 Nov 2008 20:30:42 -0600
> From: stancaldwell(--nospam--at)
> To: seaint(--nospam--at)
> Subject: Re: Water Bag Load Testing
> Matthew:
> I have unfortunately found it necessary to load test a number of
> concrete structures and have used bulk sand, barrels of water, and
> water pools. For your situation, the water pools would likely be the
> most practical. Use plastic sheeting and plywood forms to temporarily
> hold the water over one area. Then reuse the water and materials in
> the next area. This method is relatively simple and straightforward,
> and therefore, relatively inexpensive. However, all load tests are
> fairly expensive because of the required instrumentation and
> monitoring.
> Good luck,
> Stan R. Caldwell, P.E.
> Richardson, Texas
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at:
> *
> * This email was sent to you via Structural Engineers
> * Association of Southern California (SEAOSC) server. To
> * subscribe (no fee) or UnSubscribe, please go to:
> *
> *
> *
> * Questions to seaint-ad(--nospam--at) Remember, any email you
> * send to the list is public domain and may be re-posted
> * without your permission. Make sure you visit our web
> * site at:
> ******* ****** ****** ****** ******* ****** ****** ********

Get 5 GB of storage with Windows Live Hotmail. Sign up today.