Need a book? Engineering books recommendations...

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

Re: Basement Walls

[Subject Prev][Subject Next][Thread Prev][Thread Next]
My $0.02 worth:

Although I don't design many basements here, I have designed plenty of
garages cut in to a slope and three of the four walls are below grade.

1. Pinned-Pinned is tough to build since you cannot backfill until the
floor diaphragm is properly attached. I usually design as a cantilivered
wall, requiring the contractor to fully backfill and compact before
installing the floor framing. This way, the only load transferred into the
floor diaphragm is live load surcharge and whatever seismic loads the
design engineer decides exists below grade.

2. One should check with the contractor before assuming the garage slab
will resist sliding at the bottom of the wall. Usually, this slab goes in
much later.

Bill Allen

> From: Horn <scott.horn(--nospam--at)>
> To: seaoc(--nospam--at)
> Subject: Basement Walls
> Date: Wednesday, August 06, 1997 10:36 PM
> My brother is an Architect and we have been involved in the design of 
> several custom homes.  We have an on-going argument about the design of 
> basement walls.  He insists that homes the Salt Lake City area 
> with basements require only 24" wide footings for basements walls.  
> Basically, the walls is pinned-pinned!  I've been able to be involved in 
> homes with owners with enough money to not complain too much about the 
> cost, and an Architect who responds well to some coaching.  
> I live in Illinois now and I've been looking at homes around here 
> (most have basements) and they do the same thing.  There's no way these 
> walls are evaluated as retaining walls.  I've checked the loads on this
> of configuration and the shear that has to be dumped into the 
> diaphragms is considerable.  The idea of preloading a wood diaphragm with
> amounts of deadload and then needing additional reserve capacity for 
> seismic loads of the structure and additional soil lateral loads is not
> appealing to me.  I have submitted to considering the retaining wall as 
> fixed at the base and pinned at the top in some instances.
> Has anyone else been pressured to not design a basement wall as a 
> retaining wall?  If there is anyone who has / does do this, please let me

> know what the justification is.
> Scott Horn