Need a book? Engineering books recommendations...

# ACI350.3-01 - seismic design of liquid detention tank

• To: <seaint(--nospam--at)seaint.org>
• Subject: ACI350.3-01 - seismic design of liquid detention tank
• From: "Derek" <derekh(--nospam--at)krahn.com>
• Date: Fri, 2 Apr 2004 10:57:03 -0800

Is anybody familiar with this code. I am new to this particular code and a
couple of things have caught my attention. Any coments would be appreciated.

1. I'm sure this is a typo, but under section 1.2-Notation the SI units
given for m, mi and mw are kNs2/m4. I am as convinced as can be that these
units should be kg/m. If the units are correct then the equations for mw and
mi given in the commentary R9.2.4 are dimensionally inconsistent. It could
also be that the dimensions for rho (mass density) given in section 1.2 are
incorrect, however the units given there are kNs2/m4 which is equivalent to
kg/m3 and would seem correct. Anyone?

2. Onto something more concerning. Equation 9-9 states that omega_sub_i =
sqrt(k/m). k being the flexural stiffness of the tank wall and m being the
mass of the wall and impulsive component of the stored liquid.

Lets assume that section 1.2 is indeed correct and I am incorrect in my
statement above. k is in units of kPa and m is in units of kNs2/m4 then
equation 9-9 is dimensionally incosistent as the units for sqrt(k/m) come
out at m/s whereas omega_sub_i is in units of rad/s.

Lets assume that section 1.2 is incorrect. k in units of kPa and m in units
of kg/m. Dimensionally now the equation is correct, however, because k is in
units of kPa (ie 10^3 Pa) then there is a factor of sqrt(1000) that has to
be taken into account. In other words the equation should be sqrt(k/m*1000).

Can anyone help, does any of this even make sense?

PS: sorry for using SI units but having a background in Australia, these are
the only units I understand.

thanks
Derek

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted