About steel beam and shear wall combinations in high-rise buildings

[member 1218881]

In high-rise buildings, as shown in the figure, are the steel beams connected to the walls in a way that transfers moments or are they pinned? If all of them are connected with hinges, how will the moments between the columns and the shear wall be transmitted? Are some of the steel beams connected to the walls we see in these pictures moment-transferring type? Because there is no cross between the beams etc. It doesn't appear either. Since these are outrigger systems, I think moment-transmitting connections are provided on certain floors. Could they be connecting the beams with hinges on other floors?

 

[HTURKAK]

The steel beams are pin connected to core walls . The concrete core is designed to resist the entire lateral load and the framing surrounding the core is designed for gravity loads . Notice that , at your the second picture , the core is constructed using jump formwork system with base plates having anchors.

The following picture from Structural analysis and design of tall buildings By -Bungale S Taranath.

 

[member 1218881]

The steel beams are pin connected to core walls . The concrete core is designed to resist the entire lateral load and the framing surrounding the core is designed for gravity loads . Notice that , at your the second picture , the core is constructed using jump formwork system with base plates having anchors.

The following picture from Structural analysis and design of tall buildings By -Bungale S Taranath.

The situation you mentioned is the situation where the curtains carry all the earthquake loads. Well, when we want to make a design where the walls carry 80-85% earthquake load and work together with moment transferring frames, can't we make continuous connections to reinforced concrete walls? I'm looking for an example image.

 

[icebloom]

It is very difficult to moment connect to the core because of concrete breakout issues due to tension in anchors from the bending - especially in thinner walls and where you have no transverse reinforcement (eg ties in the wall). You can do things like welded rebar with extra reinforcement, but it is difficult to ensure ductility. It is also difficult from a fabrication point of view due to tolerances required for casting the endplates into the core, as well as movement of the core. This is why often the cleats are site welded after the cast in plates are surveyed, and have slotted holes to give longitudinal tolerance. It is a nightmare to try design these connections and there really is not much point in my opinion.

 

[member 1218881]

It is very difficult to moment connect to the core because of concrete breakout issues due to tension in anchors from the bending - especially in thinner walls and where you have no transverse reinforcement (eg ties in the wall). You can do things like welded rebar with extra reinforcement, but it is difficult to ensure ductility. It is also difficult from a fabrication point of view due to tolerances required for casting the endplates into the core, as well as movement of the core. This is why often the cleats are site welded after the cast in plates are surveyed, and have slotted holes to give longitudinal tolerance. It is a nightmare to try design these connections and there really is not much point in my opinion.

We can provide the moments and connections under earthquake effect in the design. I actually think there are examples of buildings constructed this way. This may become easier, especially in composite column carrier systems. However, as it becomes difficult to provide the frame effect with beams after certain heights, outtrigger systems can be activated. I think it's all about design. Regards.

 

[human909]

Could you please stop trying to crowd source your student project.

Threads Started By austinb98 (Structural engineering general discussion) Forum

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