huangyhg

soft ware for tilt-up concrete wall analysis
we've tried "tilt" by pca but didn't like it that well. typically we analyze the wall with a standard 2d analysis program that can do second order analysis. model the wall with 1 ft. segments (lots of nodes up the height of the wall) and vary the section properties depending on whether the wall cracks or not. then use pcacol to design the steel. rather awkward - but we haven't found any software that's been recommended/reliable. would be interested in it if there was something out there.
well what about pcawall by pca...anyway i am not very familiar with tiltup wall..could someone list the main critical elements in its design..
i know
1. secondary moments due to p-delta are imp..
2. bowing (temp) effects need to be looked into
3. openings for windows/doors need to be examined
also what floor system is most popular with this walls?
joist/deck system??
also is 4" thick is the most common..and what thumb rule (like h/t) to determine thickness?
vbridge (visitor)8 apr 02 11:12
andiron,
i am not too familiar with tilt-up either. but, i've found some example calcs of tilt-up. the examples are in the "notes on aci 318-99 building code requirements for structural concrete" p. 23-12.
i am not too clear on how to calculate step 3, i.e. why 4/2.5? the example on p. 23-12.
we do some tilt-up engineering where i work. the best book on the subject is by hugh brooks "tilt-up design and construction manual". in this book, he does a bunch of examples using both the ubc and aci methods of analysis. the best software i have found is to make up you own spreadsheet based upon the examples shown in the above referenced book. pca wall is too complicated and i dont always think enercalc is correct.
typically we use 7 1/4" panels min (5 1/2" work sometimes)
h/t ratios of 48-55 are common
i have designed several tilt-up panels,mostly by hand. lately we have bought pca wall and i love it. it can do a second order analysis which is a must for heavy loads and thin panels. make sure that the effective moment of inertia is correctly specified for heavy gravity loads. according to aci, for columns, effective i of 0.4 ig can be used. then you have to divide it with beta d also. the bottom line is that a value of 0.25 ig should preferably be used for heavy gravity loads. wind load deflection can be checked for i eff calculated on the basis of wind loads. pca wall is particularly good when there are a lot of wall openings. as for enercalc, i like to check the numbers calculated by that program with hand.
vbridge (visitor)8 apr 02 13:21
jnichol,
thanks for your reply. i do not have the reference you refered to. i am wondering if it is possible for you to fax me an example in the book. especially, an example that has a openning in a wall. thank you again.
vbridge,
thats not a problem. where do i send it to?
whhooooops....i meant to refer to pcawall....not tilt...sorry.
pcawall was a big disappointment as its input/output was not very well documented and neither was the theory. the screen graphics were a bit puzzling as well.
vbridge (visitor)8 apr 02 13:51
jnichol,
great! you may fax it to: 616-361-1493 attn. vqp
thank you very much.
p.s. if you ever need any structural articles please let me know.
vbridge (visitor)8 apr 02 17:39
jnichol,
i've received your fax. thank you so much. the examples are excellent. it is nice to have someone like yourself on this forum. thanks again.
last but not least, thank you to all those who replied to my question.
vbridge (visitor)12 apr 02 18:56
jnichol,
i am trying to work-out the example you've faxed me, example with the opening. why is the roof dead load being divided by 2 in ms? thanks.

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