question on an example of all-in-one

[Nirvana]

example 116.4 seismic load.

Why using n=43.5/h^(1/9) to obtain the first period (1/n), not using T=Ch^x? The results from the two equations are quite a bit, one is 0.85 and the other is 0.5x.

The former equation is mentioned in wind load, which has some more limitations, such as the height of building and wind direction.

 

[PowerStroke79_PE]

IT would help if you can post the question, I don't have the all in one with me. are you referring to the natural frequency? or natural period? 

 

[Nirvana]

IT would help if you can post the question, I don't have the all in one with me. are you referring to the natural frequency? or natural period? 

first time pasted attachement, hope it works.