Concrete Reinforcement for Slotted Drain

[Rambo13]

Hi, I need to design the reinforcement for the concrete surrounding a slotted trench drain. My initial assumption is to design for flexure of a beam on grade, however, the beam is irregular shaped due to the channel. What are your suggestions? Please see attached picture. Thanks!

http://files.engineering.com/getfil...c8e3-4d47-95e6-55216ef74f4d&file=Untitled.jpg

 

[JedClampett]

Normally, these are on ground, so all the concrete does is transfer loads to the subgrade. The reinforcing looks important, but it's probably more for shrinkage and temperature.
You could design this as a beam on an elastic foundation, but that's a lot of work and your results will probably be similar to putting in #5 bars as shown.

 

[Rambo13]

Sorry, I forgot to mention that this would be on an airport hangar and needs to withstand a live load from an aircraft of 100,000 lbs. My slab lengths are 15'.

 

[hokie66]

Instead of casting the trench separately, I would cast it as a thickened part of the rigid pavement. Place the trench at the centre of one 15' panel.

 

[TXStructural]

You should probably design the concrete below as a beam (or slab) and reinforce the upper "wings" as shown. If it is a slab, just thicken the slab at the trench and continue reinforcement under the trench, as Hokie suggests.

 

[dik]

Your grating will likely be much heavier than shown. You can make the trench bottom the same as the slab and carry the reinforcing in 2 layers. You may also have cable/etc. trenches that you will have to accommodate. Done a bunch of 747 hangars...

Dik