NZS 4219:2009 Seismic Performance of Engineering Systems in Buildings - Equation 3.2 1

[IdanPV]

Hello all,

I have a question about clause 3.4 in NZS 4219, the EARTHQUAKE LOAD DEMAND.
As per equation 3.2, the lateral force coefficient shall be calculated but shall not be greater than 3.6.
The system I am dealing with shall be installed in Palmerston North (Z=0.38 per Table 3), Cp=0.85, Rc=1.6 and the system is intended to be install above ground floor, so CH=3.0.

Therefore, C=2.7*3*0.38*0.85*1.6=4.18608, which is greater than 3.6.

What shall I do in this case?

Thanks,

 

[blihpandgeorge]

3.6

 

[IdanPV]

Thank you,
Any reference for that statement?

 

[blihpandgeorge]

Equation 3.2 gives an upper limit "but not greater than 3.6". I cant see how this can be interpreted another way. To be clear, this is mobilising 3.6 x the weight of a component, ie 3.6G.

For some wider context AS1170.4, Cl 8.2(1) has a similar type clause but it is limited to 0.5Wc

 

[Agent666]

Refer to NZS1170.5, the intent is clear in there that for parts loading the max is 3.6 times the weight of the part for the ULS.

https://engineervsheep.com

 

[IdanPV]

Thank you all!