Precast Wall Feasibility 2

[Brad805]

I have a project that came back on to my desk, and I have many reservations about what is proposed. I have included a plan view and elevation below. This is to be a climbing wall. It first started with the owners cardboard plan, and after I insisted, they found an EOR that is supposed to have experience in climbing walls. I do not think they looked at the feasibility of what our client suggested to them. Our client has never had a great appreciation for lateral loads or slenderness. I have not gotten far into this, and I would like some general thoughts. It is in a low seismic zone, so the load governing the problem is the 25psf wind load. The EOR has specified some gravity loads at the top of the panel, but those will not be a huge challenge if the general design is stable.

My problems:
1. 6" does not pass the general stink test in my mind.
2. Joints at intersections will need to be dry connections. They will be of paramount importance. I will never win the argument to field cast proper joints that would make my job far easier.
3. Base connections they will want will be simple dowels. Non-contact splices.
4. Only 4 pieces, so eng budget not great.

I can likely persuade them to go to an 8" wall, and add flanges to the ends of the wing panels. My question is do you think it is feasible or possible?

 

[Brad805]

Doublestud, 8pt lifts are not great on site. You stand to vertical, and then move to top rail lifters. Demould day is the worst. There are tons of benefits to tilt decks and shipping in cradles, but alas, not my decision to make.

I like the simplicity of the stiffeners as well. It will delay the process, but it is only four pieces. This is not a case of the owner leading the design. My client is a very practical guy, but from time to time he comes up with some whopper ideas. I expect he has budgeted this and not one part of this project will be good for me. It does not help that I kind of pooped in his corn flakes last week when he tied my hands behind my back on a job for the spring.

 

[DoubleStud]

Brad, so when you tilt it up, it is like 30 ft span then? The high lifters to the bottom of the panel? That's hard not to crack if it is just 6" panel.

 

[Brad805]

When lifted off the deck or trailer it would be something like the 5min calc below. Once vertical, they must lift from the top rail if they need it to hang vertical. If the dowels are not too tall, they may be able to work with a slight tilt of the panel. In that case they would not move to the top rail. I do not think this part of the project is difficult.

 

[DoubleStud]

Cool Brad. What software is that?

Can you toggle the option on top left to erection? I want to see the result.

 

[Brad805]

Doublestud, that is LECWall. The erection part changes the F'c value and allows you to change the lifters. In this case they will likely ask to use just the bottom four for erection, but I doubt that will work for the reasons you mentioned. They build a number of partially composite panels and this software includes that option. Edward Losch, PHd, writes this software and is very involved in the PCI Sandwich Panel committee. Over the years he has been overly gracious with his time answering questions.

 

[Tomfh]

Do it as four rectangular panels, with lots of cast in plates stitching them together.

The risk is the whole thing blowing over. You probably want more than the regular pins at the base.