wood frame building large door

[rittz]

Attached is a sketch for a 60’ x 120’ x 18’ wood structure on a pile/grade beam foundation and slab-on-grade. The client requires a 40 x 16 door in the end for access for wide machinery. Any Ideas on a design concept? Maybe we would be looking at a steel portal frame or could a glulam timber design be feasible. The lateral wind load would be taken by the roof diaphragm and the foundation with some sort of connection.

 

[woodman88]

You have two 10' x 16' shearwalls. Place a drag truss over them and a foundation under. Attach the shearwalls with a beam for the diaphragm chord forces. Just how much force are you looking it?

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[rittz]

Responding to woodman88 Thanks for responding I appreciate it.

The client is planning to use a bi-fold door. I don't know yet how the door is attached to the truss or the foundation below. I have no experience with such large doors in a frame wall. I was assuming that the lateral wind load on the door (25 psf) would be shared in some fashion between the tuss and the foundation The lateral load on the shear wall would be framed into the roof which is sheeted with plywood. I don't know what you meant by attaching the shear walls with a beam.

 

[BAretired]

Design of the door might be interesting. Similar to hangar buildings with wide doors to allow the entry of airplanes. Shear panels each side of the door could be vertical trusses or shearwalls.

BA

 

[dik]

I've used a couple of Schweiss bi-fold doors with HSS columns and W columns for 'vertical beams at the ends with HSS headers. These can be braced back to your long walls. Check their web site for details.

Dik

 

[XR250]

Neglecting the door for a minute, how are you getting the out of plane loads of the gable end walls into the roof diaphragm or over to the perpendicular shearwalls? Very difficult on a building like this (and have it built correctly anyhow). I typically balloon frame the gable ends with 2x8's or 2x10's
Adding a 40 ft. wide door would be tough unless you use a ceiling diaphragm.

 

[dik]

The TPIC and likely the TPI in the US have info on bracing trusses... catch the attached...

Dik

 

[BAretired]

dik, adobe wouldn't open that file.

BA

 

[dik]

Try again...

Dik

 

[dik]

and again...

 

[dik]

Last upload works... don't know why the others didn't...

Dik

 

[BAretired]

Got it this time, dik. Thanks.

BA

 

[rittz]

Question? how do some of you fellows seem to find out that a new post (forum?) on a new subject (forum ?) comes in that you are interested in responding to?

 

[BAretired]

I review the Structural Forum or any other fora which interest me to see the list of new posts which have been started in that particular forum. If interested, I respond. Otherwise, I move on.

BA

 

[dhengr]

Rittz:
Just like BA does it. But, last night I was looking at the stars and in the constellation Rittziopia the stars were aligned just right to indicate that Rittz needs some ideas and help. So here I are.

I am not sure how this would work, but by working with the truss supplier, could you do the following? Two vertical trusses, 10' wide and 16' high. This gable end truss would have its bottom chord at 16' elev. (the door head), so it would also have 2' high heels out at the eaves. This certainly would be a crazy rigid frame truss system, might be osb or plywd. sheathed both sides. It doesn’t have much roof load on it, but must interact with the roof diaphragm, and take wind loads perpendicular to its plane, as well as those from the whole bldg. which end up in its plane, plus the door loads. It would require pretty husky chord members in both the vert. truss and the gable truss at the door jamb lines. And, it would require some sort of hold down hardware out at the 2' deep heels, 18' long hold down rods from the found. to the top chord.

Alternatively, make the two vert. trusses 10' wide, and 18' high at the eves and about 20.5' high at the door jamb line. The jamb chord on these vert. trusses would have 2 or 3-2x6s (or whatever) cut short at 16' elev. to act as a bearing seat for the door header/gable truss which would be 40' long, btwn. these two vert. truss bearing seats. At the roof plane, you might use steel strapping for continuity btwn. the trusses at the door jamb line; or you might hold the top/sloped chords down, 2 or 3(1.5") so you can install these 2 or 3 added, laminated, top chord members for continuity.

Thicken and reinforce the edges of your approach (apron) slabs. Also, form a nice radius on its two outer corners, or the first time they drive a combine or tractor in there, they will break (crack) a 2 or 3' by 45̊ corner off those aprons.

 

[rittz]

Dhenar: That is absolutely hilarious. I am so glad the stars were lined up in my favor. You made my day. Thank you for sending that solution. Sadly it came a little late. I had already checked with the stars and Dhemprecop (cw/2 moons) advised me to tell the client it would cost him big bucks for me to design that door complex and another bundle for him build it and he should build 2 20 ft doors. He agreed. Quad erat demonstratum. …..
Regards,
John, Peng age 83

 

[XR250]

It actually would not be that bad. Put a ceiling diaphragm in the building (plywood on the bottom of the trusses along the entire width of the building and length being what ever is necessary to react the shear into the sidewalls) If the doors are sliding type that span vertically from the slab to the bottom of the trusses then you are done. No jambs required and no big bucks required.