Search results for query: *

I have a question about AASHTO 2020 Section 6.8.4, snip below for convenience: I am designing a temporary tower for support of bridge erection. The tower will be a truss tower consisting of HSS members for the primary longitudinal legs and lateral bracing, and with thin diagonal lattice...

In case anyone from NCEES is reading this thread, in my mind there's an obvious solution. Allow people to bring their own pdfs on a thumb drive. Then they can keep their own bookmarks, highlights, notes, etc in the codes as they were previously allowed to with hard copies. And for most of us, I...

Thanks hardbutmild. I was pretty mixed up when I started this thread, but I think I've gotten it straightened out now: -If the beam is fully in compression, crack control is irrelevant and not checked -If there is some small amount of decompression at the bottom flange of the beam, I would...

Thanks KootK, your explanation for point 1 makes it very clear for me now. Regarding point 2, I think this may bring me back full circle. I am planning to count on the non-prestressed reinforcement as crack control, not the PT. So doesn't it make sense in that case to use fss in the non-PT...

A few questions on this: 1. So to make sure I understand correctly, this would mean fss = (the actual final stress in the tendons) - (the minimum prestress needed to eliminate tension at the tension face due to service loads)? 2. I realize I left out something significant from the AASHTO...

I don't have any detailed insight on this but I'm most familiar with CSI Bridge for this. It works reasonably well and they have responsive customer support when issues come up. You might look into LUSAS and Sofistik as well. I haven't heard anything about the AASHTO 10th Edition yet - do you...

You might have better luck making this into a long term plan. A good first step could be applying to major international companies elsewhere in the EU that are either based in the US or have offices in the US. Not sure how many of these there are in France, but you may have better luck in places...

I'm not sure if I fully understand that second blurb. Does it just mean fss = the stress in the prestress tendons at service loading? Should it include effects of long term losses?

KootK, thanks for the background info. That all makes sense. Now I guess to restate my question a little more simply - how do I go about calculating fss in a beam with bonded prestressed reinforcement as well as bonded regular reinforcement?

I am reviewing/updating an existing spreadsheet designing post-tensioned I-girders to AASHTO. There is a check included for control of cracking distribution reinforcement in accordance with 5.6.7. I'll copy the relevant equation below so we're all on the same page. The spreadsheet is now...

Hi all - I am opening this thread back up with a new question. I'm now pretty settled on using equation 6.25 for this purpose, after the discussion on here and some subsequent discussions with a senior engineer in the office. Now I'm honing in on the ρ*fyd term which in the equation which is...

I was able to find this, in EN 1992-4. a3 is defined above as 0.5*d, so its not a very large additional depth. The contractor right now is calculating bending in the bolt by taking a moment with the lever arm all the way to the end of the bolt, and then subtracting a moment due to triangular...

Interesting that that paper explicitly defines pullout failure as equivalent to bond failure: ACI 318 on the other hand defines pullout failure and bond failure as two separate cases, with pullout based on just bearing underneath the head of the anchor. I did just notice this sentence: If...

Sorry, that was a typo. These are anchor bolts, M-series to Eurocode. So there are threads, but I guess probably not large enough to develop meaningful interlocking forces like with a rebar.

How would you account for the mechanical interlock between the grout and rebar to increase the bond capacity? I believe that is included implicitly in typical rebar development length equations, and the pullout equation for anchor bolts in the codes I have seen only accounts for bearing area...

Does anyone have thoughts on the second part of the question? Is bending affected at all or is e1 for the moment arm still valid?

Thanks TLHS, that confirms what I was thinking there. I am now thinking that pullout isn't a case I should consider, since there is no head or nut at the bottom of the anchor bolt, the "pullout" capacity would just be the same as the bond strength between anchor bolt and grout.

Good point stevenal, that's correct. The contractor has specified the rock type, and are using adhesion and friction coefficient properties *that are supposedly* specific to the interface between the rock and the grout. (*Though, I'm a bit in the dark where the properties they're using are...

Those pages are talking about bond strength, and they are helpful just to confirm my assumption about how I should account for bond strength. But bond strength is not what I had doubts about. My doubts are related to other cases such as pullout or breakout, as well as bending in the anchor bolt.

Thanks for sharing dvd, interesting read. It confirms my thinking about bond strength. But in the section about pullout strength they don't directly address if the embedment length would be effected by having anchor tape. However the main value I got from this is to remind me about anchor...