I'm trying to understand how to reconcile the following two provisions regarding torsional irregularity in chapter 12 of ASCE 7-05:
First, Section 12.3.3.4 requires the 25% amplification of design collector forces determined from Sec 12.8.1, which is the Equiv Lateral Force Method, when you...
Whoops-just re-read your question. The problem is not that the straight bars aren't hooked, but that the hooks themselves don't have sufficent Ldh. (And neither would the straight bars even if they were hooked.)
VTEIT, That's the concern. For a #8 bar, the required Ldh is at least 15.3" (if you have more than 2" cover on the back side). With an 8" bar with 2" end cover in a 16" wall, you only have 13" of available Ldh at the most, and less if you can't get those hooks right out to the 2" limit.
Mike: Yeah, I know that embed plates with weldable rebar would work. But I would end up slaughtered, butchered, and cast into the concrete wall during the reinf observation, and that that would cause voids in the wall...
miesc: I read throught the previous thread you referenced--Thanks. However, I don't think it addresses walls that are as thin as 8" - 10", unless I missed something.
Ah!--it's obviously an area of some dispute.
VTEIT: the hook is not to develop the bar out in the wall, but rather to develop a tension-controlled section at the corner itself, which resists *negative* moment.
SplitRings: I've also added corner bars in between the horizontal reinf to tighten...
It is common practice to analyze basement walls using tank-tables, which usually indicate high negative moments around corners and at counterforts. My question is how the bars around corners can be used for tension reinforcement in walls that are too thin to allow the minimum hooked-bar...
Aggman--I'm with you there. We've also used the TJI vibration analysis forever for all of our floor designs for that very reason. Thanks for the comment.
Mike, The tile/terrazo deflection limit makes sense to prevent cracking, though I never thougth about it before--is that limit just borrowed from standard masonry rules? Usually my joists are sized for that type of stiffness (for comfort levels, using TJBeams's Prorating system), but not always...
I have been pondering allowable deflection limits for our residential design standards for high-end residential *FLOORS BEAMS*(wood framed with LVL, glu-lam, and steel beams). I am trying to develop a list of criteria for younger engineers, and I would appreciate some input from some of y'all...
Sorry about that last post--I was writing as you were:)
Is it possible that the contractor lifted the soils upwards as the hydrant was yanked out of the ground, causing the slab to rise during the demo?
As a side note: the presense of expansive soils could explain the cracking regardless of whether the cracks were present (and invisible) before the patch, or formed afterward.
demayeng, Is it possible that there are expansive soils at this location? If so, it is very possible that the cracks could be from heaving below the patch, caused over time as the water from the broken hydrant slowly seeped into the surrounding clay soils. This would explan the crack pattern and...
Bedrock1977,
As noted by the 3 comments above, wood structures (almost) always have shearwalls of some sort. Often on squatter structure or structures with a lot of wall, the sheathed exterior walls along with the interior gypsum-board covered walls are sufficent to resist wind without special...
I'm in the Front Range area of CO where we usually have wind speeds between 110 mph and 140 mph 3-sec gust, so we use shearwalls in residential construction all over. It's just like any other building:
1. Determine winds loads on structure per ASCE7;
2. Get a feel for the resistance by adding...
Ron, I guess that makes sense if we are differentating between (1)Material/system/component/work and (2) Type. If that was the case, then a sample clause in the inspection statement could be as follows:
Material/Component: Reinforced concrete;
Inspection Type: Rebar placement, cleanliness, and...
Section 1705.2(2) of the IBC states that the statement of special inspections shall identify "the TYPE and extent of each special inspection". That section also states that, for each TYPE of special inspection, the engineer must indentify its frequency (continuous or periodic).
I always thought...
