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Re: Retaining Wall Loading

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For a brief synopsis see J.Bowles, foundation analysis and design, lateral earth
pressures, p. 517 or Zeevaert, Foundation Engineering

Chris Lillback

Javier Encinas wrote:

> If your structure is in a seismic zone, then definitely you should include H
> and E in your load combinations. The dynamic effect of the seismic force in
> a retained mass of soil was studied by Mononobe and Okabe as a particular
> case of the Coulomb theory, which assumes a wedge of soil exerting a
> pressure against the wall.
>
> Unlike your statement that the soil seismic load becomes less severe than
> the original pressure, this dynamic effect actually increases the static
> pressure H due to the dynamic force from the soil wedge. In addition, if the
> wall has a heel, the inertia force from the portion of the backfill above
> the heel should be considered too.
>
> Javier Encinas
> ASDIP Structural Software
>
> -----Original Message-----
> From: J. Karim Hosseinzadeh <jkh(--nospam--at)jamkar.com>
> To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
> Date: Monday, May 01, 2000 4:31 PM
> Subject: Re: Retaining Wall Loading
>
> >I know this answer is late, but I now have a similar design situation and I
> >am pondering against my past experience, whether I should combine earth
> >pressure with seismic. UBC 97 Code sections 1612.2.2 & 1612.3.3 don't say
> >that H "should be" combined with seismic, what it says is, "where H is to
> be
> >considered" it should be added to the basic load combination. Now the
> >question is "where" do we consider H. I have always been taught to ignore
> >seismic forces acting on the portion of the building which lies underground
> >such as a basement. The reasoning is that the inertia forces of the
> >earthquake and the ground movement are in opposite direction. Therefore the
> >retaining wall either moves away from the retained earth or pushes against
> >it. At either case the load acting behind the wall becomes less severe than
> >the original earth pressure.
> >I would be interested to know if there are any hard rules about this
> >subject.
> >---
> >J. Karim Hosseinzadeh
> >JAMKAR ENGINEERING, INC.               Tel. 949 250 0522
> >Newport Beach, California                            Fax 949 250 1527
> >jkh(--nospam--at)jamkar.com                                   http://www.jamkar.com
> >
> >
> >----- Original Message -----
> >From: <RainCat1(--nospam--at)aol.com>
> >To: <seaint(--nospam--at)seaint.org>
> >Sent: Wednesday, April 19, 2000 5:03 PM
> >Subject: Retaining Wall Loading
> >
> >
> >> Are seismic loads applied to a retaining wall in combination with the H
> >load?
> >> UBC97 section 1612.2.2 & 1612.3.3 indicate that the H load should be
> >combined
> >> with seismic. ASCE 7-95 does not give load combination that include E &
> H.
> >>
> >> Could anybody shed light on this? Thanks a lot!
> >>
> >> Rainier C. Catubig, S.E.
> >> San Diego, California
> >
> >
> >
> >
> >
> >
>