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RE: Shear Walls

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	I seem to be having a hard time in interpreting the results of STAAD
for the shear wall forces. The results are in Stresses (psi and kPA) and not
in Forces (lbs and KN). I use the manual method of determining the forces on
the walls . (The analysis is that the walls are cantilever beams). I know
that there is a conversion for STAAD's result but I need a confirmation. Its
like multiplying the results with the involved dimensions of the wall. My
manual analysis always results in a more conservative design. 
	Any suggestions / comments are most welcome !!!
	Thanks 

> ----------
> From: 	T. Eric Gillham PE[SMTP:gk2(--nospam--at)kuentos.guam.net]
> Reply To: 	seaint(--nospam--at)seaint.org
> Sent: 	Monday, March 29, 1999 6:36 AM
> To: 	seaoc list
> Subject: 	Fw: Shear Walls
> 
> Allan:
> 
> Kumusta!
> 
> I would say that keeping the shaft R/C AND keeping it connected is the way
> to go.  Dual systems, IMO, are the best R/C configurations for seismic
> resistance.  The SMRF, if properly detailed, provides an excellent energy
> absorbing system, and it can accomodate some pretty high drift levels.
> The
> shear walls, depending on the configuration and sizes, provides some
> measure
> of deformation control.  Given that the frames are taking most of the
> vertical loading, axial load on the walls is usually pretty low, allowing
> them to exhibit good hysteretic behavior.
> 
> On the other hand, if the walls are in such a configuration that they
> bring
> about a lot of torsional response, you might look at using soft walls, but
> for a 7 storey structure I would think it wouldn't be too much of a
> problem.
> 
> Besides, I think the PI is similar to Guam in that R/C is the prevelant
> material.  Best to keep things simple (read: leave it R/C), rather than
> introduce some separation detail or switch to another material which may
> result in construction headaches.
> 
> My .02 pesos.
> 
> T. Eric Gillham PE
> GK2 Inc.
> PO Box 3207  Agana, Guam  96932
> Email - gk2(--nospam--at)kuentos.guam.net
> Ph:  (671) 477-9224
> Fax: (671) 477-3456
> -----Original Message-----
> From: Francis.Ang(--nospam--at)toyota.com.ph <Francis.Ang(--nospam--at)toyota.com.ph>
> To: seaint(--nospam--at)seaint.org <seaint(--nospam--at)seaint.org>
> Date: Friday, March 26, 1999 11:52 AM
> Subject: Shear Walls
> 
> 
> >I am designing a building that is seven story high. And here in the
> >Philippines, we are required to use elevators for 5-storey high
> structures.
> >Can anybody out there offer me suggestions? I intend to use the elevator
> >housing as a shear wall. That is based on my experience.  For a change, I
> >was thinking of providing an elevator housing but is not connected to the
> >Lateral Force Resisiting Element.
> >The structure would act as a special space moment resisting frame rather
> >than a dual structure.
> >Suggestions are most welcome.
> >I know that by using a shear wall, there is a need to consider many
> things
> >in the seismic analysis.
> >Thanks in advance guys !!!!!
> >
> >Allan Yango
> >Structural Engineer
> >
> >> ----------
> >> From: Charles Greenlaw[SMTP:cgreenlaw(--nospam--at)speedlink.com]
> >> Reply To: seaint(--nospam--at)seaint.org
> >> Sent: Thursday, March 25, 1999 6:17 PM
> >> To: seaint(--nospam--at)seaint.org
> >> Subject: Re: Residential Flexible/Rigid Diaphragm Analysis
> >>
> >> Responding to Dennis Wish's recent solicitations:
> >>
> >> Dennis, if you are gleaning prior postings for an Online article, I
> >> submitted quite a bit on the diaphragm rigidity issue in 1998 on Aug 29
> >> and
> >> Nov 18 and 21.
> >>
> >> I still think the code's demand that we regard diaphragms as conforming
> in
> >> reality to the extremes that human-invented figures of speech suggest
> >> ("rigid" and "flexible") is the dumbest thing since when young ladies
> were
> >> similarly divided into two distinct categories. You remember, there
> were
> >> "good girls" and "bad girls". And nothing else. The first kind were
> good
> >> for
> >> marrying and bearing your children. The second kind were good for other
> >> purposes we need not specify here.
> >>
> >> Like with this spurious code expectation that we can tell the
> difference
> >> in
> >> diaphragms and rely on the result, telling the difference between good
> and
> >> bad girls hasn't been all that certain. My great-grandfather F.B.Ogden
> in
> >> Oakland wouldn't let his daughters wear any red clothing, because it
> was
> >> "the sign of the fallen woman". His judgment seems quaint now, but the
> >> voters back then kept re-electing him as a superior court judge.
> >>
> >> In my own youth, the girls themselves, when it came to being good or
> bad,
> >> seemed to sort out behaviorally as "rigid" or "flexible", so to speak.
> >> Performance-based evaluation, we might proudly call it now.
> >>
> >> But back then, the girl classifications were just for guideline
> purposes.
> >> You didn't get sued or lose your license and retirement savings if you
> >> mistook one kind of girl for the other and made a poor choice. But with
> >> the
> >> building code, mistaking rigid for flexible is disastrous as soon as an
> >> adversary's expert opines you got it wrong. The fact that the building
> >> itself didn't care is only a curiosity. You are into an expensive
> defense
> >> for violating a regulation intended to protect people from injury.
> Serious
> >> business.
> >>
> >> So how did this pitfall come to be inflicted on us? I suggest looking
> to
> >> Mark Gilligan's posting on 2-27-99, the pertinent part of which is:
> >>
> >> >I have observed that a number of code provisions have been adopted
> with
> >> >little technical data backing them up.  The SEAOC Seismology committee
> >> has
> >> >generally done a good job but ultimately the individuals find
> themselves
> >> >having to make decisions on subjects that they have not seriously
> >> >researched.  In this context people use their  best judgement.  I
> believe
> >> >that the provisions on redundancy probably fell in this catagory. The
> >> >problem is that what may seem rational occasionally isn't.
> >>
> >> I discussed Mark's implication in early March at a SEAOC dinner meeting
> >> with
> >> another regular code formulation participant, who is with a state
> agency
> >> keenly concerned with seismic codes. He confirmed that code language
> very
> >> often comes from one person on a committee, usually an energetic and
> >> forceful advocate, and gets approved with little or no validation in
> >> depth.
> >> Usually voting committee members shoot from the hip on little
> >> knowledgeable
> >> debate, because the agenda is too full, and was distributed too close
> to
> >> the
> >> meeting date to absorb and find flaws in. And the plane home leaves too
> >> soon. This is what my own experiences confirm. On the few issues I can
> get
> >> up to speed on and find big defects in, it is still hard at the meeting
> to
> >> get an edge in wordwise. I have in past writings referred to these
> >> committees as "empires" and been told that is an understatement.
> >>
> >> I do better at Board of Registration meetings. I have spoken on
> >> enforcement
> >> issues and pointed out an anomaly:   The Board disciplines individual
> >> engineers for failure to fulfill the duty of due care, such as
> mistakenly
> >> making a code violation, on a single element of a single building. But
> the
> >> code provision itself was originated with less care than taken by the
> >> offending engineer in its use. And the code doesn't just affect that
> one
> >> building, it affects all buidings. With less care taken. How do you
> Board
> >> of
> >> Registration members want to discipline that??  Blank stares follow; no
> >> complaints were received so they have no idea. But why should the
> >> struggling
> >> code users suffer the burdens? Why not the code originators? The
> stories
> >> of
> >> code formulation proceedings are plainly stories of failure to render
> due
> >> care.
> >>
> >> Questioning "authority" itself, not the orders disseminated by
> authority,
> >> is
> >> where this subject's inquiry should head.
> >>
> >> Charles O. Greenlaw, SE    Sacramento CA
> >> Vietnam Vet who hasn't forgotten what can happen
> >>
> >>
> >>
> >>
> >
> >
> >
> 
> 
> 
>