Dynamic modulus of elasticity 1

[ramsha]

I am using E = Edynamic = 1.3 x Ec28 in my ETABS model for the calculation of total displacement and inter storey drift for a 84 storey apartment building.

Is this approach correct ? I found a relationship betn Ec28 and Edyn in BS8110 but not in UBC1997.

 

[Qshake]

I am not familiar with this increase unless there is a arguement in the British Standards for accounting for aged concrete.

For example, if you're using a 500 yr return period for your earthquake motion or coefficients it is appropriate to account for an increase in the strength of concrete which is typically taken as about 1.25 to 1.5 times the initial 28 day strength.

Also there is some consideration to be given to a cracked section due to deterioration pending the location of the beams/columns and to what environment they may be subjected to.

Regards,

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[ramsha]

Qshake
I am a first time user of this forum and never thought I will get a reply so quickly.

Thanks for your comments. I have used the Edyn for wind loading only as per BS8110 and just wondered to see any provision in UBC 1997.
For EQ analysis as per UBC1997 I have used E=4730 * fc^0.5.

regards
Ramsha

 

[Qshake]

RAMSHA - I hope you find the site friendly and very useful. It's a great place to share information and we can use more insight from different codes around the world.



Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.