Free wall with a height of 15 m

[Plantec]

Hello,

we have to design a free wall with a height of 15 m. There are no ground pressures on the wall, only the wind. At 2 m of the wall, there is a sewer (depth 2 m, radius 0.5m). The ground at the site is bad (soft clays,... in the first 6 m, then loosely packed sand for 3.5 m, then a good layer of sand of 3 m). The wall is asides the railroad (vibrations).

This wall is about 1 km long. It is in a coastal area, not much buildings in the area, so the wind can be quite strong (design value approx. 1.5 kN/m²).

I am thinking of using a type of berlinerwall, where we vibrate steel H-beams (e.g. HEB-300) in the ground every 4 or 5 m. Between these beams we can place prefabricated concrete plates.

Of course, the people I work for want a cheap design. Are there according to you guys cheaper methods of constructing this wall? Do you see problems in a design as a berlinerwall?

Thanks a lot,
Karel

 

[Focht3]

Is this a sound wall?



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.

 

[Plantec]

To Focht3:

It's not a sound wall. The wall is around a place to stock sand, lime, ... (I don't know the english term). It is placed on a new area for industrial activities. The city is concerned they won't attract industry if the dust is blowing in the wind. So they obliged the firm to build a 15 m wall. I think there is a little bit of political vendetta between the city and the firm, but that doesn't concern me.

Greetings,
Karel

 

[Focht3]

Okay, it's really a screen of sorts. Where is the site?

Do you have to use concrete? I'd suggest a look at aluminum or similar lightweight material, unless you think the locals might take shots at it...then use lightweight concrete. Or steel plate.

The principal load will be lateral - mostly the moment because of the eccentricity. You need to get good shear strength and soil profile information for the top 3 or 4 meters along the fence alignment. I would suggest that you use p-y curves to model the soil behavior. They are non-linear and do a good job of predicting the maximum bending moments. Deflection is another matter: none of the current methods is very good at predicting deflection behavior, particularly at working loads. If deflection is an issue, you might consider braces or tie-downs to control deflection.

P.S. Your English is quite good -



Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.