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Re: Basement wall restrained by wood floor

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James:

I agree with you. Furthermore, in Midwest the basement wall usually is plain
concrete. Per BOCA '99, Page 215, 8" plain concrete wall can span 8 ft with
7 ft
unbalanced fill of GW, GP soils (30 pcf). The only rebars are usually
(2)-#4 horizontal at the top and bottom of the wall. Stress analysis would
indicate
that the concrete stresses comply with ACI 318-95, Plain Concrete Chapter.
The cost difference between reinforced retaining wall and the plain concrete
wall is obvious.

Jie Lu, P.E., S.E.
J. Lu International, LLC



. ----- Original Message -----
From: James F Fulton <James_F_Fulton(--nospam--at)RohmHaas.Com>
To: <seaint(--nospam--at)seaint.org>
Sent: Thursday, August 26, 1999 7:14 AM
Subject: Basement wall restrained by wood floor


> In 99.9% of the residential construction I've seen, the basement wall is
> supported by a strip footing, usually 20" wide or so. This type of wall
> relies on the support at the top provided by the first floor. In one
> direction, the direction of the floor joists, not only the floor deck but
> also the joists act to provide the restraint. Pretty stiff and pretty
strong
> in this direction. In the other direction, parallel to the joists, a
blocking
> or bridging system has to be used to transfer the transverse shear at the
> bottom of the rim joists, that bears on the sill plate that's anchored
bolted
> into the top of the wall, to the level of the floor deck.  In this case,
the
> floor deck is indeed providing most of the strength and stiffness it would
> seem. But I don't see why it cannot be relied upon do its job. To design
the
> wall as a cantilever against backfill loads has expensive implications for
> residential construction now that a structural footing is needed.
>