Water flow rate

unfortunately, the two don't directly convert. You'll need to look at the old fluid mechanics books for the equations of fluids hitting surfaces.

I'll have a look through my books and, if I find anything not too long winded, I'll post it up.
 
Bernoulli and Venturi only exist to bully poor engineers.
 
What a coincidence!

I was flipping through my copy of Temporary Works: Principles of Design and Construction, to see if they had listed anything for this; and I noticed one of your pictures on page 271.
 
BS 5975:2008+A1 2011, section 17.5.2 has methods of calculating water forces. If it is for a stream or slow moving river then it can be calculated and applied to a scaffold structure but for wave or tidal forces I would recommend steering well clear, based on past experience!
 
Iv got one of each! A parapet wall on river bank and a hanger for concrete repairs on a pier! Take a look tomorrow, iv got the flow rates but need the equivalent pressure on tubes and uplift on boards
 
Quickest (read: most basic) formula I could find is: q=500 v^2

q is given in N/mm^2
v is the flow velocity

You'll need to assign the Cw value which, I think is 0.47 for tube but double check.

A decent safety factor for dynamic loads such as crisp packets, turds or condoms that come floating by wouldn't hurt either.
 
Disregarding all engineering theory but applying some common sense might come up with a larger gap.. Say 48.3mm?.. Between the boards. Should release some of the pressure. Not calculated as its not easy to calculate wats actually happening.... Too many variables.. practice though.. Wat.. Clients must ensure a safe system of work with the increased gap in boards of course.
 
I would have said go with a grill on the water board side but if that's not an option then a decent gap is just as good.

On the wave loading side though, I agree with biffo. Try to avoid that nightmare. For a similar job, I used the magic-float system. It provides a good cover for the EA and a single layer can be loaded to 5.0 kN/m^2 so not too shabby.

Getting into wave loading is a big drama on the temporary works front.


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That looks like a tidy system. Does it stack up cost wise, compared t + f?


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Nick-CDS said:
Quickest (read: most basic) formula I could find is: q=500 v^2

q is given in N/mm^2
v is the flow velocity

You'll need to assign the Cw value which, I think is 0.47 for tube but double check.

A decent safety factor for dynamic loads such as crisp packets, turds or condoms that come floating by wouldn't hurt either.
Click to expand...

I think that Cw is 0.63 for tube & 1.86 for boards. BS5975 is fine for river work but BS 6349-2:2010 is the best reference for work in the sea
 
The web decking is similar cost to conventional scaffold due to the higher cost of hire and rope access technicians but quicker to erect. Disadvantages are it deflects a lot more and requires specialist rope access technicians to erect. Horses for courses as usual.
 
BS5975 shows how to calculate river flow loads, although you need to find out max flow from Environment Agency.

Also you will need to calculate buoyancy uplift if a boarded platform is to be submerged.
 
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