It's been a while since I've done a seismic design, but if my recollection is correct, it seems like I decided there likely would be at least a reduced seismic sliding force due to the foundation weight, but that ASCE 7-05 didn't seem to mandate that it be included.
Since I didn't previously know (or forgot) that 12.15.5 existed, I guess I'm going to dig myself a deeper hole. The commentary says that a tension tie A) has axial tension over the entire section B) a level of stress in the reinforcing causing every bar to be fully effective C) limited concrete...
If you put in a ACI tension lap splice, this should transfer the tension load. I've never seen anything implied in ACI that this tension lap splice is only valid for flexural members. That would seem to go against how the ACI code works. You can add the closed ties if you like, but if there...
What reason does you P.E. give for not putting a nut on the threaded rod? Is their only response that we haven't done this in the past, so it isn't necessary, or is there some other reason?
Hurricanes and Earthquakes have much bigger coverage zones and are designed by typical building codes where Tornados are not. The worst hurricanes have wind speeds of 165 mph where tornados can have wind speeds of 200 - 300 mph. Steve Gregory and Woodman88 both make good points in that it is...
The 1997 UBC had some seismic risk factors for various non-U.S. regions. I don't have one in front of me to check on haiti. Parts of Venezuela were risk category 4, but it seemed like it reduced as you went into the carribean.
StructuralEIT, Steellion:
Currently the Civil exam is 1/2 breadth and 1/2 localized knowledge. The breadth portion is 20% structural. The localized knowledge portion could be 100% structural if you choose. So if your civil emphasis is Structural, 1/2 + 1/5*1/2 = 60% of the exam can be taken...
NS4U:
The detail the way you presented it should provide continuity between the two (top) tension bars. To elaborate on my first post. The splice as it is shown is not really a splice between the bottom bar from the left and the top from the right. The way it will work is the top bar from the...
Is this an elevated slab or slab on grade? Are these flexural bars, or are they for some other purpose? Seismic or non-seismic? For flexural continuity, you'd need some mechanism to transfer the tension from one tension bar to the other. If both bars could be tension bars you'd need a...
miecz: `11.7.1 Provisions of 11.7 are to be applied where it is appropriate to consider shear transfer across a given plane, such as: AN EXISTING OR POTENTIAL CRACK, ...'
They even give you a 1.4*lambda value for mu in concrete cast monolithically. Doesn't that tell you at some point it may...
Good post RonRoberts & JAE. That makes sense. Miecz: they have a coef of friction value for concrete cast monolithically that is part of the shear friction equation. You need to design for shear friction as a failure mode anyplace that a crack may occur, regardless if it's in the same or...
miecz: I think any place where the concrete is loaded to a point where a crack may form should be checked for shear-friction regardless if poured at different times.
I've always considered shear-friction to be a secondary check to the normal shear capacity calculation. I've never seen that it...
