hali

I have not heard of this criterion. Is this in a code?

I doubt anyone from the State will be available to address such minor things lol. My only remaining assumption about this would be that they used the modifier As-required/As-provided to reduce the development length. But regardless, thanks for helping me out with this. I think I'll go back to some textbook basics and see if I missed anything in there.

So shouldn't the negative rebar be developed adequately into the wall? According to AASHTO's development length equation it would be about 36" straight and 9.5" hooked. It looks like it wasn't properly developed

Alright guys I'm back and here's the specific problem where I'm having confusion. The following link is a State standard detailed drawing of a range of different RCB (ranging in span lengths and heights). https://www.odot.org/bridge/2009-sb/brd_std_2009-lrfd-sb-531.pdf I'm dealing with a double 6'x3' RCB. The A1 bars in the top slab are #6 bars, so their basic development length is about 14.5". Now this was not developed into the walls because I'm assuming you cast the slab last so the concrete in the walls has already matured. But shouldn't it have 180 degree hooked bars at least? Also I don't think this wall-slab connection can be considered a simply supported one since rebar is being developed from both layers from the walls.

Thank you @UmarMakhzumi and @Badar (BAZ) for your responses. I'll apply these to a problem I'm dealing with at the moment. I'll probably have some more questions as well so I'll be back again lol

AOA everyone. Recently I've been very confused with development length and how its provided in different components. I have a few conceptual confusions about it and then a few practical and design aspects of it. I'd really appreciate help on these. Do we provide/check development length for simply supported beams (i.e. check it past the max moment?) Where do we need to check for development length? (in my understanding, we need to check it almost everywhere, where you need to ensure full moment capacity) What is a "critical section" when we talk about development length? (refer to the attached picture) I think its the point beyond which we need to ensure development At a wall-slab joint where both the slab and wall are 8" thick, if #6 bars at 8" c/c need to be developed from the slab into the wall, I found that even with the 90 degree hook, the development length is at least 14". How do you satisfy development length in such a case? For hooked development length ldh, is it the length up to the hook or is the length that includes the length of the hook? For example for a 90 degree hook, would it be 12db+the length beyond the critical section or just the length beyond the critical section up to the hook? I've seen in a few places on the internet that people include the 12db into the development length. This stuff has been eating up gray matter from my brain for a few days now. Any help is appreciated. Thanks!

AOA everyone. Recently I've been very confused with development length and how its provided in different components. I have a few conceptual confusions about it and then a few practical and design aspects of it. I'd really appreciate help on these. Do we provide/check development length for simply supported beams (i.e. check it past the max moment?) Where do we need to check for development length? (in my understanding, we need to check it almost everywhere, where you need to ensure full moment capacity) What is a "critical section" when we talk about development length? (refer to the attached picture) I think its the point beyond which we need to ensure development At a wall-slab joint where both the slab and wall are 8" thick, if #6 bars at 8" c/c need to be developed from the slab into the wall, I found that even with the 90 degree hook, the development length is at least 14". How do you satisfy development length in such a case? For hooked development length ldh, is it the length up to the hook or is the length that includes the length of the hook? For example for a 90 degree hook, would it be 12db+the length beyond the critical section or just the length beyond the critical section up to the hook? I've seen in a few places on the internet that people include the 12db into the development length. This stuff has been eating up gray matter from my brain for a few days now. Any help is appreciated. Thanks!

Thank you @Simple Structures for taking the time out to draw all that. That was very helpful. For the most part, I can figure out where where the rebars are to be provided (tension locations), its the fine detailing of the rebars that I want to get comfortable and confident at.

AOA everyone, I have always kind of struggled to understand how exactly you provide reinforcement in joints like beam-column joints or joints of box culvert. More specifically, how to ensure transfer of moment through the joint. Does anyone have any pointers or rules of thumb for providing reinforcement in joints? Thanks!

Thanks @UmarMakhzumi I'll give it a read.

Thanks Simple Structures. I searched for the John Hancock Center in particular and could only find the outside dimensions, like you said, very generic. I was actually interested to see how the tube structure differs on the inside from a moment frame. And how exactly were the floor slabs cast.

AOA everyone, Hope everyone is staying safe during these troubled times. I have been looking into designs of famous structures for a few days and I was wondering if there are any websites or books that have structural designs of famous buildings like the John Hancock building for example. i wanted to recreate these structures maybe in a FEM program to understand them better. Does anyone know where i can find structural plans for these buildings? I'm guessing detailed plans wont be available but even something basic can be really helpful as well. Thanks.

Hello everyone. Extending on Salma's questions, will the purlins be sufficient as bracing elements against lateral torsional buckling of straight simply supported beams?

Thank you for letting me know Zain.

AOA everyone. I just wanted to know, is the ACI coefficient method for analysis of two way slabs still valid? Or some other method is preferred over this one? Regards, HA