I am looking for some back up literature on pre-tensioned anchor rods to fill in a few gaps in the information that I have been able to find todate:
1. I have seen recommendations in the past not to pre-tension rods with yield strength below 60-70 Ksi. I basically understand that there are...
Oops, one mistake in my post when I said K factor for seismic, I meant R factor.
Glad I was able to help. Your response was the only positive in a bad day where I got sideswiped by the cancellation of a $2.5 billion (going onto $8.5 billion - which kind of explains the cancellation) project.
The commentary in ASCE 7-98 helps a little (see p. 241-242). It indicates that rigid structures of concrete or steel may reduce the velocity to zero time interval to 0.1 - 0.5 sec. But even at t = 0.1 second your distance to zero is 1.25 ft., which could still translate into a large force on...
Wondering if anyone has a simple technique for determining the required thickness of a head plate on an anchor bolt embedded in concrete.
I'm not looking for a conservative method that gives me a safe solution, but rather looking for a way to assess a reliable capacity for an existing bolt...
I don't think that you get very large capacities out of Chance anchors (10-20 kips I believe). So assuming that you could install them at a 45 degree angle you would need 20 to 40 anchors. With group effects spacing requirements you would need a large area, and a big cap to ties these together...
Typical working loads at 1/5th. of the wire rope capacity is similar to lifting lugs which are designed for 5 times the specified lifting capacity to account for multiple handling and abuse such as impact damage from being dropped small distances. But since docking ships is not done under a...
With liability concerns, the presumably third party designer of the foundation, would not design his foundation for anything less than the capacity of the anchorage.
Sometimes it seems that if there are two ways to approach a problem, that with some clients it pays to do it the wrong way first, because regardless they'll want to see the other way too, and so you only have to change it once. This applied more to the days of manual draughting where it wasn't...
A 300 kip lateral load (even assuming it is 100% horizontal with no additional vertical uplift component) will require a very massive AND deep foundation. Using a combination of passive pressure, base rocking and base friction and ignoring several limiting factors (such as the suitability of...
One key thing to remember is that internal explosion and external blasts present different loading criteria.
Internal blast generally requires relief (blow-out panels) or reflected pressures significantly increase the overall blast load on the structure. Factory Mutual has information for...
I currently work for a major EPC consultant in the oil & gas industry. We are ISO 9001 registered, and have committed to checking all calcs. This is actually too much. Some stuff needs checking, maybe even more than once, other items could probably go with no checks.
In my earlier commercial...
On some very large industrial rigid frame structures that I have seen (high eave heights, and heavy crane loads), and where floor trenches/pits are a factor or could very likely be in the future, a foundation with a pair (or more) of piles in line with the frame/truss span have been used. These...
It would actually depend on whether the lateral load restraint system was a moment frame, (particularly if this column was a participating element), or some other system like shear walls or bracing. If for example the column was part of a line of columns that were braced, and ignoring beam...
In theory as the engineer of record the structural consultant is on the hook for everything structural. With the usual fee structure and insane schedules it is almost a virtual impossibility to actually achieve full control of everything, requiring that we rely on other structural engineers to...
Frost penetration and jacking/heaving is also a function of soil type, so (assuming that you have a geotechnical engineer on the project) he may be able to give you some site specific guidance.
This is consistent with the Canadian codes, but when cladding materials are not able to handle large movements, h/500 may be the necessary limit, and crane columns can require more restrictive limits if crane manufacturer's tolerances so dictate.
Seismic deflection limits are to be found in the NBCC Part 4, in the section on seismic loads. Deflection limits according to clause 4.1.9.2.3) are 0.01hs (h/100) for post-disaster structures and 0.02hs (h/50) for all other structures.
The other limit would be situation specific limitations...
Useful in Canada at least:
1. Weight in lbs/ft. of metric designation steel beam, divide the metric weight by 1.5 (i.e. W200x27 weighs about 18 lb/ft. - W8x18). - Note although we are officially metric, many of our industrial clients are U.S. based and insist on their projects being in Imperial...
Well you will only achieve deflections in the order of the limit values if the loads approach the design loads, and then only if the selected member's design was governed by deflection. Research in the UK a number of years ago showed that the average floor load in office buildings was about 15...
A further comment to Tip #2
While a moment frame and braced frame in series (i.e. the same column line) probably won't work, in parallel they can. While the differential stiffness may make such an arrangement undesirable, particularly for seismic reasons, sometimes architectural and or...
