Liquid Containing Concrete Tank with Concrete Frame on Top as per ACI

[Erudawn]

I am looking for advice on designing Liquid Containing Concrete Tank with Concrete Frame on Top using American Codes-- especially the design of the concrete frame.

The project location being in a high seismic zone, I would need special seismic detailing for the concrete frame, where typically I would use a Response Modification Factor (R) equal to 8.

I am well aware of the provisions of ACI 350 especially the hydrodynamic load calculations as per ACI 350.3, and for the concrete tank I would use an R = 2 (impulsive).

My question would be, if I have a structural model comprising of both the concrete tank and concrete frame where I am using the lower value of R = 2,
should I provide special seismic detailing for the concrete frame? Or the special detailing wouldn't be necessary since I am using a lower value of R for the concrete frame?

Thanks.

 

[HTURKAK]

Will you pls be more specific ?. I assume you modelled the base slab+concrete walls + roof beams and slab as a closed frame.Is this assumption true ?

Although the use of roof beams + walls frame action is not explicitly stated, my opinion is the R values for walls and roof beams should be the same for compatibility reasons .

I would also remind that ACI318 is not applicable in this case. (Clause 1.4.9 This Code does not apply to the design and construction of tanks and reservoirs.)












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