Hi all,

I need to verify a piping system according ASME B31.3 and I've the following data for earthquake:

2.2.6 EARTHQUAKE (SEISMIC FACTOR)
Earthquake shall be considered for high seismic zone (ZONE 4 as per Uniform Building Code).

Near source factor: Na=1 , Nv=1

My question is:
how to simulate in CAESAR this kind of eartquake?

I've simulated the EQ applying a uniform load in both horizontal direction using a value of 0.4 G's. It' correct?

Another question:
It seems that these values (in chapter 2.2.6) are for structures in general, should be considered (same values) for piping system too?

TY.

Seismic analysis using equivalent static method, should be analysed applying uniform loads in G's.
Do not forget to activate g's in special execution parameters!

Hi pradeepd,

my concern is about the values to use in this analysis. In accordance with my first post, if I have a seismic zone 4, is correct to use 0.4 G's in both horizontal direction?

TY.

Hi TY,

It looks like you're asking two question...

If you're asking about applying seismic force both horizontal direction, then it'd be correct unless owner or Standard(base on your Project) specify that you need to consider the vertical direction.

And the other case, using 0.4G's in seismic zone 4, amount of the seismic force differ from the site conditions. As long as your equation is correct and complied with project regulation, then it's ok.

For seismic load, you can check the Seismic Wizard in CII. But, you need to know first which code your seismic load should be designed. You should be familiar with ASCE or NBC's earthquake load calculation. A visit with your counterpart in structural engineering would help you understand it better.

The code is UBC(uniform building code).

Hello,

As MK posted: "As long as your equation is correct and complied with project regulation, then it's ok."

So, with your project regulation, in this case UBC code, if you read it you will find the formulas to calculate the seismic factor.

Use the values defined for your specific project (ZONE, Na, etc.) with those formulas and you will achieve the value you must consider for your seismic acceleration. Maybe 0,4 G's maybe not. Just a code checking will give you the answer.

IMPORTANT: Read all the code for any clarifying notes.

Regards,

PG