Earthquake Forces on Pile Foundations
Earthquake Forces on Pile Foundations
(OP)
Good day!
I am currently designing an equipment foundation on piles. I'm wondering if do I have to include the inertial force of the large mass concrete in addition to the earthquake force due to the equipment and consider these effects on the piles OR I just have to consider the earthquake force due to the equipment only.
Do I have to consider the earthquake effects of foundations OR just the superstructure only?
Please cite references if available.
Help! Your response is very much appreciated.
Thanks!
I am currently designing an equipment foundation on piles. I'm wondering if do I have to include the inertial force of the large mass concrete in addition to the earthquake force due to the equipment and consider these effects on the piles OR I just have to consider the earthquake force due to the equipment only.
Do I have to consider the earthquake effects of foundations OR just the superstructure only?
Please cite references if available.
Help! Your response is very much appreciated.
Thanks!





RE: Earthquake Forces on Pile Foundations
RE: Earthquake Forces on Pile Foundations
RE: Earthquake Forces on Pile Foundations
RE: Earthquake Forces on Pile Foundations
Mike McCann, PE, SE (WA)
RE: Earthquake Forces on Pile Foundations
My work is related to geotechnical engineering and when I have to do lateral analysis and if I do not get the enough information from the structural, I try to estimate the static base shear coefficient (Cs) and apply it to the vertical capacity of my element (i.e. pile or soil-cement column for example) to get a preliminary lateral force to check deflections and stresses in the foundation.
So, going back to the OP question, when you do static seismic analysis, I was thinking that pile caps are included in the calculation of the mass of the structure, as this weight may be large and therefore can have an important effect in the base shear value. Anyways, again, I work in geotechnical and would like to see the structural engineers opinions.
RE: Earthquake Forces on Pile Foundations
RE: Earthquake Forces on Pile Foundations
RE: Earthquake Forces on Pile Foundations
Just to mention, the equipment has also been designed using dynamic analysis and the number of piles has been optimized to prevent the structure from falling within the resonance range. The number of piles provided were checked with static analysis but without the inertial forces due to the foundation. Considering this additional inertial force will affect my initial pile design and providing additional piles will gravely affect the stiffness of my structure, i.e. the system will resonate. I just want to assure that I will be able to justify my design if I have to rework this headache.
Happy Holidays!