Seismic Overturning Moment on Silo
Seismic Overturning Moment on Silo
(OP)
Hello,
I calculated the seismic response coefficient, Cs = 0.0534. I know that I get my base shear by taking Cs x (the weight). How do I calculate the overturning moment? The silo is 39'-9" tall and 10'-10" in diameter.
Thanks!
I calculated the seismic response coefficient, Cs = 0.0534. I know that I get my base shear by taking Cs x (the weight). How do I calculate the overturning moment? The silo is 39'-9" tall and 10'-10" in diameter.
Thanks!






RE: Seismic Overturning Moment on Silo
BA
RE: Seismic Overturning Moment on Silo
RE: Seismic Overturning Moment on Silo
RE: Seismic Overturning Moment on Silo
RE: Seismic Overturning Moment on Silo
Thanks
RE: Seismic Overturning Moment on Silo
RE: Seismic Overturning Moment on Silo
Basically idea is; Impulsive mass of liquid acts on the lower part of the tank and convective mass of liquid on the upper part. During seismic event; the mass of fluid in the lower part of tank behave like rigidly connected with tank and moves with wall and imparts seismic inertia forces called impulsive mass. Slushing fluid in the upper part; termed as convective mass which oscillate with their own natural frequency introduced hydrodynamic pressure on a wall.
All over; the response of a tank structure in EQ action and how to account for the sloshing effect in structre design is an intricate problem.
You may refer the ACI 350-3 for designing the tank for hydrodynamic effect. Step by step method for calculating the hydrodynamic forces on tanks and time period has been provided.
also you can find detailed guidance on this subject is available at website National Information Centre of Earthquake Engineering at IIT Kanpur; INDIA.
http://www.nicee.org/IITK-GSDMA_Codes.php
May find helpful to you.
Best Regards_ VH
RE: Seismic Overturning Moment on Silo
If it's a flat-bottom tank on grade, then you can use API-650, AWWA D100 or similar standards- is the tank itself designed to any standard?
Generally, for tanks of any size, the consideration of sloshing reduces the seismic loading.
Also refer to ASCE 7. One of the approaches used there is to treat the tank contents as a rigid mass, ignoring sloshing. If seismic loading is not high, that will work okay.
RE: Seismic Overturning Moment on Silo
RE: Seismic Overturning Moment on Silo