Parameters of Seismic Design no defined by ASCE7-16

[Jatfuentes]

Dear Engineers,
I will like to know if some of you have designed structures according ASCE 7 outside USA.
In this case is necessary to get the factors SD1, SD2, Ss ,etc for that country.
I found in API 650 2018 section EC-4.3 “ Sites not defined by ASCE7 methods” a vey simple an practical procedure that basically is to asume “Z” ( the maximun horizontal acceleration in rigid soil with 10% of probability of be exceeded in 50 years) equal to Ss of ASCE 7. And then all the othersr factors (Sd!,SD2,Fa,etc).
The engineering office of the client claims that this specification only apply to tank design and can not be applied to other structures.
I will like to know what is your opinión about this client claim.
Thanks

 

[JStephen]

I would be inclined to agree with your client.
Your assumption might be reasonable, but to base it on API-650 statements if it is not an API-650 tank would not be appropriate.
For the most part, the seismic content of API-650 is going to be derived from ASCE 7 and other published sources, and those sources would be the ones to go to for more general applications.
You might ask the client what IS to be applied to your structure- more specifically, if there is some other building code applicable to it.

 

[Lomarandil]

Sure, I use ASCE 7 all over the world (either to supplement a local code, or replace one that isn't in place).

It's important to understand and convert those basic inputs like Ss/S1 or basic wind speed when necessary - but the theory remains solid.

Finding those basic inputs in a format that can be converted is quite a challenge, but often doable. Where is your project?

Will the project specifications allow it is another question entirely.

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just call me Lo.

 

[r13]

The key is the acceptance of the local building authority regarding the code in concern. As opposed to API, I believe ASCE7 is less well known abroad. I wouldn't accept a design unless I am familiar with the code, or reference, it used in the cal., because I wouldn't know whether the originator used correct provisions or not, and I don't know how to check it.

 

[HTURKAK]

Jatfuentes (Structural);

The engineering office of the client is right with their claims..API 650 code (Appendix E.4.3 SITES NOT DEFINED BY ASCE 7 METHODS ) is applicable for the above ground storage tanks.

The reason is, AST has two periods Impulsive period and sloshing period (convective).That is, just two spectral values are enough to perform the tank design.

The impulsive period is short period and in the range of 0.1 sec and Ss is always applicable. The convective period could be in the range 3-15 sec depending on the dimensions.

 

[jjl317]

Not sure if this would help, but one potential sources of ASCE 7 seismic criteria (S1, Ss, etc.) would be UFC 3-301-01, which provides ASCE based design criteria for locations worldwide where a US government based facility exists (if the job location happened to be near such a facility).

 

[Jatfuentes]

Thanks for your responses, they have been very helpful.
I understand that:
The design spectrum or soil acceleration diagram Vs Periods is made without considering the type of structure to be built in it locally, it is a dynamic response characteristic of the site and depends on the periods of the soil, soil type and accelerations.
The type of structure is considered when applying the “R” factor of ductility.
ASCE 7 does not give a spectrum for each type of structure of course.
The question is "How to calculate the factors of ASCE 7, (Ss, S1, So, Fv,) for places outside USA."
The works are in Pisco and Cusco (Peru)
Thanks again

 

[r13]

This might help. Link

 

[Lomarandil]

As Retired13 points out, for Peru, you will need to meet the requirements of the local seismic code.

If you want to use ASCE 7 to supplement those requirements and improve your design, here is the data from UFC 3-301-01 that JJL mentioned.

Lima isn't very close to Cuzco, so you'll want to consider that carefully, especially in a country as seismically active as Peru.

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just call me Lo.