Anchors into existing concrete 6

[beaming]

I need tie down some wood-frame shearwalls to an existing slab. I found a program PDA-2, Powers Design Assist 2, which does an astounding job, but I can't believe the values. I also doubt my own values.
e.g.
I find that a 3/8" PowerStud 2 embedded 2" into 2500 psi cracked concrete, at 2.875" from an edge is good for 1400 lbs.

If you are familiar with PDA, please comment.

 

[MiketheEngineer]

Not familiar with PDA, but Simpson (Strong-tie.com) has numerous tables and some software available to easily verify these loads.

Note that SOME tables show ultimate loads with a tiny disclaimer leaving the Safety Factor up the design pro... I usally use 5:1

 

[Lion06]

This really should be drone with App. D and compared to a factored load. In that case, you shouldn't be applying your own safety factor.

 

[racookpe1978]

I've used the Hilti calculation forms in the past, but that was 4-5 years ago using manual data - not an on-line application.

Hilti's values depended strongly on the actual concrete depth, width (distance of the hole) from the edge, psi of concrete, and depth of the new fastener. Pull out strength (resistance to up/down or sideways force at failure) determined which table you looked up values in.

 

[transmissiontowers]

Hilti has a very nice (and free) windows Profis software that will do all the calculations and tell you the fasteners that meet the qualifications.

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[oldrunner]

You might consider Simpson Strong-Tie's Titen HD's. Get their ICC report. They now have approvals for shear and uplift. Simpson also has a pretty good freebee program for designing with any of their products.

I like the Titen HD's because you just drill a hole through the sill plate and into the concrete and then screw the bolt into the concrete.

 

[beaming]

I am answering somewhat prematurely because I haven't exercised the software enough to be sure, but, as Mike said, Simpson has a free package called ACI318 something like PDA2, but it is pint-sized and weak-kneed and nowhere near as convenient and fast and thorough to use as PDA2, and they seem to produce the same answers. They both claim to follow ACI 318 Appendix. D. I make so many mistakes that I couldn't claim it.

I will do a little exercising and report back. Thank you all. I appreciate your help.

 

[beaming]

I have compared Simpson and Powers software enough to raise some questions, based on the fact that the pictures made me think that they were the same hardware, but differently branded. Running the software, I get somewhat different answers, so I suspect that they are different. I may or may not try the Hilti package, but I will beat around on this keyboard until I get happy enough to specify something.
I find that Simpson is OK enough for the yes-no question "Will this work?"; PDA2 is much more convenient for looking at a range of anchors. I wish that they had agreed exactly, and that the two lines were the same, but my original and main concern is now satisfied, that the program results are reasonable.
Thank you all very much.

 

[beaming]

The Powers and Simpson anchors are identical, made by the same people, coming from Taiwan of the same ships. Names differ.
The sw input is quite different, and caution is needed. One wants eff. h, the other wants embedment h, etc. The only thing I can't reconcile so far is that Simpson requires greater edge distance. I am glad to have both, and the price was right.

 

[transmissiontowers]

Try out the Hilti Profis S/W. I believe you go to their web site and can D/L the package.

http://www.us.hilti.com/holus/page/...sf?lang=en&nodeId=-114925&selectedOid=-116113

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[wannabeSE]

Beaming,
Don't forget to use LRFD load combinations before inputing loads if you are designing per ACI 318.

 

[a2mfk]

You said you are putting a shear wall on a slab? What do you know about the slab?

 

[Cadair]

I cannot speak to the accuracy of the programs; however, I can say what it could be.

App. D doesn't quite fit for anchors on wood sill plates, and often isn't needed. Here is AWC's FAQ on the matter.

http://www.awc.org/HelpOutreach/faq/FAQfiles/ACI318-AppendixD.html

That links to the study done that shows how App. D relates.

This is now being adopted by codes and standards. The CA code states...

2305.1.4 Sill plate anchor bolts. [BSC, DSA-SS, DSA-SS/
CC and OSHPD 1, 2, 3 & 4J As specified in Section
1908.1.31 modifications to ACI 318, the allowable lateral
design strength for sill plate anchor bolts in shear parallel
to grain is permitted to be determined using the lateral
design value for a bolt attaching a wood sill plate to concrete,
as specified in AF &PA NDS Table 11 E, provided the
anchor bolts comply with all of the following:
1. The maximum anchor bolt diameter is 5/8 inches (16
mm).
2. The anchor bolt is embedded at least 7 inches (178
mm) into concrete.
3. The anchor bolt is located a minimum of 21/2 anchor
diameters from any concrete edge that is parallel to
the sill plate; and
4. The anchor bolt is located a minimum of 15 anchor
diameters from any concrete end that is perpendicular to the sill plate.

The next Wind and Seismic provisions for the NDS will have similar language, and I wouldn't be surprised if the next IBC is similar.