Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Code section 1802.2.7

[Subject Prev][Subject Next][Thread Prev][Thread Next]
The purpose of the provision is simply for the issue to be addressed. If the soils engineer deems there is "zero" surcharge on the subterranean elements of the structure due to seismic loads, they need to provide that to the structural engineer and your done with it.
Jeff Coronado, S.E.
----- Original Message -----
To: 'To'
Sent: Thursday, January 28, 2010 12:42 PM
Subject: Code section 1802.2.7

I?m dealing with a plan checker here in SoCal that has claimed we should be complying to section 1802.2.7 of the building code for our single family house design.


Item 1802.2.7 states, in regard to adding earthquake induced soil loads:  ??A determination of lateral pressures on basement and retaining walls due to earthquake motions??  needs to be calculated. 

But here?s the part that throws me. 

An exception is granted in 1806A.1 limiting the requirement to retaining walls over 12 feet high, and that section is adopted by DSA and OSHPD, but, curiously, not by the main code section, 1806.1. 

So this means I can construct a hospital without requiring the added lateral loading, but not a house? 


This makes no sense to me.


There are well-established exemptions in the better part of the LA Basin about this, with both LA County and the City of LA going with the 1806A exception and exempting walls below 12 feet in height, (which ours are).  In addition, the County of Los Angeles cites a State of California Public Resources Code for the Alquist Priolo EFZA and the Seismic Hazards Mapping Act which exempts site retaining walls from the requirement, a further confusion.


But there it is in the CBC code; there is no denying it.   


The soil engineer does not agree that its necessary and the structural engineer concurs.

So, as the Architect, I?m greatly confused over this and would like to get some input about what you all think of it.


Is there any greater consensus on the applicability of this section on a house design?