Rapt,
Thanks for your response. I had been out a few days, and just finally got back to checking on this. Anyways, this may be a dumb question (Note: I am just recently getting into PT Design, and am working under a senior engineer who has a lot of PT Experience but is from the PT Data mold...
In section 9.2 of the sixth edition of PTI's Post-tensioning manual, they have a step number 5B - Calculate Post-tensioning force using "allowable average compression". I realize that this step isn't a code enforced step of the design, but more of a rule of thumb (an unwritten rule, to be...
Thanks for all the insight. I may have misrepresented the seminar notes . . . the seminar was an ASCE seminar in Vegas, at least one of the speakers was Bijan Aalami (from the seminar cover sheet, who I didn't know about personally), they did define the slab band as I described it above, but...
A supervisor went to a seminar on PT Design. In the seminar, they defined something called a "Slab Band" or a "Drop Band" as a slab thickening used primarily to get more drape on your banded tendons, but was not to be designed as a beam (ie, no beam shear steel). Limitations were placed on the...
We may be forced into the fire truck loading - the architect met with the fire marshall today . . .
as for the height restriction bumpers, we would do that, but the owner evidently wants delivery trucks to have access to that part of the structure, which are just as tall as any large truck...
I have an elevated plaza/parking slab on a condo project we are working on. There is a daylight basement type of parking beneath the building, and an area of parking on the 1st floor slab. There is retail shops and restaurants going in on the first floor, so the owner wants to have delivery...
I have heard from some engineers that it is more economical to avoid drop caps for punching shear by adding up to some number of inches of concrete. The thinking is that a good majority of cost in concrete construction deals with the formwork materials and labor. (This seems to be similar to...
Thanks for the responses, and I agree with all of them. Just a quick follow up question, when you determine how much stiffer the beam is than the concrete slab, do you compare the beam stiffness (moment of inertia) with a similar width of slab, or would you compare the beam stiffness with the...
I am relatively inexperienced with concrete slab design, and had a few punching shear issues to get worked out that are outside of the cookie cutter examples found in the ACI. Note that this is my first Slab design and I am working under a supervising engineer who has a lot of experience in...
The detail you are talking about is shown in the AASHTO Spec for Structural Supports of Highway Signs, Luminaires and Traffic Signals. Chapter 11 deals with Fatigue design, and the diagram in Example 7 of that chapter is a fillet welded socket connection as you describe. I am not an expert in...
Not really answering your question, but if your columns are heavily loaded, they may need to be designed for omega loads just for being part of the lateral system . . . See Section 8.3 in Part 1 of AISC 341-02.
In ACI 318-02, section 18.3.3, it defines the different classifications of PT Slabs, with type U being the typical uncracked PT slab with the tension stress limit equal to 7.5 (f'c^0.5) (which is increased from the 1999 and earlier codes which put the limit at 6 (f'c^0.5)). At the bottom of...
Thanks for the response. I am familiar with the TradeReady header (which would be the equivalent of a 600T800-68), but I guess my main question is how well a track would work in a continuous span condition, where there are negative moment failures at each stud support. I have a call in to...
I was looking at using a light gage top track to distribute loads to load bearing stud walls, which I have never even explored before. In looking at deep leg tracks (user defined as 600T400-68 and 600T600-68 in the programs that I have), you find out that those types of tracks have all kinds of...
Thanks for all of the input. The design we are asked to review and stamp is a more complicated Cantilever Luminaire and Traffic Signal light pole (40' tall pole with a 45' arm attached to the pole). We are working directly for the manufacturer of the pole, so are not even involved with the...
We have a client who does traffic signal structures for different jurisdictions. This isn't our normal line of work, but we know how to use the AASHTO 2001 "Highway Signs, Luminaires and Traffic Signals" code, and it is just like any other type of structural design.
Anyways, the project that...
I have the latest RamSteel with the floor vibration software, the AISC Design guide 11, plus several articles written by Thomas Murray (co-author of Design Guide 11).
With all of this information at my hands, I still question whether I am using the design recommendations correctly, at least...
Trying to determine the impact force from an object falling from multiple stories . . . we will have a wood platform that we need to design so that it stops the object. To refresh everyones' memory, the average force is called "impulse" and is equal to the change in momentum divided by the time...
