Question about building classification for seismic 2

[AlexH15]

Hey everyone,

I am designing a concrete moment frame with a steel braced frame on top that holds bulk material (ore). How should I classify this building? Currently I'm analyzing it by taking the total horizontal load from the ore and adding that to the seismic loads of the steel braced frame and concrete moment frame. Also, I'm in seismic zone 3 so I'm not even sure I can use a concrete moment frame also. A sketch is attached FYI. Thanks in advance.

 

[jdgengineer]

Seems like you are in Chapter 15 of ASCE 7 "Non-Building Structures". I'd review the list of options there I'm sure there is something close to what you have.

Concrete moment frames are allowed in high seismic (at least in US), you just need to meet special detailing requirements.

 

[Shu Jiang PEng SE]

It seems that you have a structure with vertical lateral resistance combination. not sure what design code you used for you design. Per AISC 7, you may use two stages analysis procedure, the lower structure shall be designed as separated structure, the reaction from the analysis of the upper structure amplified per the ratio R/p of upper structure to the lower one; the upper structure is analyzed with equivalent lateral force or other appropriate methods.

Also, some requirements are required to use the two stages analysis procedure in your design. You can refer 12.2.3.1 and 12.2.3.2 in AISC7-10 for details.