Structural Engineering: 2007-04-15

Saturday, April 21, 2007

Re: Masonry Skewed Shear Walls

Aldo Gonzales

A simplified model to finding either of the eschewed wall component
stiffness is to add a horizontal spring to the top middle of the
eschewed wall and perpendicular to the stiffness component to be
determined. Set the spring stiffness to the sum of other walls parallel
to that spring. For a flexible diaphragm, limit the walls whose wall
line crosses the eschewed wall. If there are no wall lines crossing the
eschewed wall then nearby walls need to be considered but reduced in
stiffness due to the flexibility of the diaphragm.

Test your model!! If the y walls are reduced, so will the x stiffness
component of the eschewed wall. If your analysis does not respond in
that way, something is wrong!

Recommended code wording.
"The stiffness components of a lateral brace, eschewed in plan, shall be
determined by a rational analysis that includes the influence of other
lateral bracing not parallel to the eschewed lateral bracing."

David Merrick, SE
Sacramento, CA

Notes....

100%+30% rule
All codes allow significant eschewed wall to be used if the building is
designed by using 100% shear plus 30% of shear affects from the
perpendicular direction.

Component method
Component stiffness of an eschewed wall approaches the correct answer
when parallel and perpendicular affecting walls have sum stiffness of at
least 20 times greater than that of the eschewed wall, in both
directions. For a flexible diaphragm, those parallel and perpendicular
walls are limited to those whose wall lines cross at the eschewed wall
location.

Consider the eschewed wall where no parallel nor perpendicular walls are
in line with the eschewed wall. Push in one direction and the eschewed
freely tilts. When there are moment frames in x direction and shear
walls in y direction, and then any eschewed wall will have a
much-reduced stiffness in the y direction, possibly the component
stiffness, or less, in the x direction.

The real solution is in between the two cases above. To envelope the
worst possible condition is easily done by designing the building with
the 100%+30% rule. I have yet to consider if the "component method" is
conservative for the eschewed wall with the 100%+30% rule. It might be
best to consider two cases one with a reduced or zero eschewed wall
stiffness.

Code writers of IBC 2006 apparently have given up on most being able to
understand the above and now require a building that is significantly
influenced by an eschewed wall must use the 100%+30% rule or be analyzed
by a dynamic analysis procedure. I believe the IBC2006 defines what
eschewed walls are significant. A flexible diaphragm can be computer
modeled if the flexure stiffness (E) can be set low and the shear
modulus be set to a high value (G>>E). Such a manipulation will need to
be check for errors due to large differences in stiffness values and
significant figures in the stiffness matrix operations.

I was looking at S-Frame and found it is possible, but I have yet to run
sample problems.

The 100%+30% rule alone may not be conservative for some structural
elements near the effectively low stiffness of an eschewed wall. A
dynamic analysis can wrongly model the eschewed wall with two walls to
represent the stiffness components. Eschewed wall stiffness components
are dependent on the other walls.

One person requested to produce a cleaned up version of the spreadsheet
for determining the eschewed wall reaction. Any more

>From: "refugio rochin" <fugeeo@gmail.com>
>To: seaint@seaint.org
>Subject: Re: Masonry Skewed Shear Walls
>
>Skewed Shear Walls
>Break components of load acting on shear wall into perpendicular and
>parallel loads.
>for flexible diaphragm, load acts on wall by tributary area.
>look at ACI 530 for out-of-plane loads, and in-plane shear wall loads
>and analyze by the appropriate equations.
>
>
>2007/4/20, Aldo Gonzales <allmin02@yahoo.es>:
>
>
>>I'm working on a project with Masonry skewed shear
>>walls and flexible diaphragm. Can someone help me with
>>some example from some book, references to papers, or
>>let me know how should I analyze it? I would
>>appreciate any comments. Thanks.
>>
>>
>>
>>
>>
>
>

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Friday, April 20, 2007

Re: SHOOTINGS

Gary:

I respect your opinion, but what is misleading is the notion that criminals
will register their fire arms.
I also want to apologize for using this great forum for debating gun control
and I will not pursue this any further. My heartfelt prayers went out to
the students and faculty and their families the day I first heard the tragic
news.

Ray Shreenan
----- Original Message -----
From: "Gary L. Hodgson and Assoc." <ghodgson@bellnet.ca>
To: <seaint@seaint.org>
Sent: Friday, April 20, 2007 4:51 AM
Subject: Re: SHOOTINGS

> That statement is totally mis-leading. The same can be said for cars and
> trucks and yet we require every one to undergo testing of some sort and
> place restrictions on those who have some sort of problem, e.g.
> handi-capped, colour-blindness, etc. I see nothing wrong with requiring a
> strict licensing regime for fire-arms.
> Gary
>
> Raymond Shreenan wrote:
>> Guns don't kill people, people kill people
>>
>> R.S.
>> ----- Original Message -----
>> *From:* ASC <mailto:ggg@bigpond.net.au>
>> *To:* Struct EngAssoc <mailto:seaint@seaint.org>
>> *Sent:* Tuesday, April 17, 2007 1:43 AM
>> *Subject:* SHOOTINGS
>>
>> The rest of civilized world never ceases to be amazed
>> with America's love affair with guns.
>> And with America's unwillingness to do anything about it.
>> 36,000 people are dying each year this way, most by accidents.
>> That deranged individual was not a criminal by design, was he?
>> Did the accessibility of guns made the world safer for him or
>> anyone else?
>> Tell me more about the blessing of firearms...
>> About the freedom it brings...
>> About safety and security...
>> And how it limits the powers of the government...
>> And how it protects from communists...
>> Do you really believe in this?
>> As a young engineer in So Cal I once met an older engineer, who did.
>> Sincerely, Gregory from Oz
>>
>>
>
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Gunman from Jacobs Engineering in Bldg. 44 of Johnson Space Center (NASA) in Houston.

Friday, April 20, 2007

I know that NCSEA wanted more publicity for our profession but I just heard that there is a gunman who is a contract employee of Pasadena based Jacobs Engineering (the employee was from their TN offices) at the Johnson Space Center in the NASA Bldg. 44 Communications. It appears that Jacobs is doing contract work for the NASA Space Station. Houston Swat is currently in the building but it has not been confirmed if shots had been fired.

This kind of publicity we don’t need. I won’t provide and thoughts because it would be politically uncorrect at this time.

Sincerely,

Dennis

Dennis S. Wish, PE

California Professional Engineer

Structural Engineering Consultant

C-41250 (Exp. 3/31/09)

dennis.wish@verizon.net

http://structuralist.spaces.live.com

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Re: SHOOTINGS

That statement is totally mis-leading. The same can be said for cars
and trucks and yet we require every one to undergo testing of some sort
and place restrictions on those who have some sort of problem, e.g.
handi-capped, colour-blindness, etc. I see nothing wrong with requiring
a strict licensing regime for fire-arms.
Gary

Raymond Shreenan wrote:
> Guns don't kill people, people kill people
>
> R.S.
>
> ----- Original Message -----
> *From:* ASC <mailto:ggg@bigpond.net.au>
> *To:* Struct EngAssoc <mailto:seaint@seaint.org>
> *Sent:* Tuesday, April 17, 2007 1:43 AM
> *Subject:* SHOOTINGS
>
> The rest of civilized world never ceases to be amazed
> with America's love affair with guns.
>
> And with America's unwillingness to do anything about it.
>
> 36,000 people are dying each year this way, most by accidents.
>
> That deranged individual was not a criminal by design, was he?
>
> Did the accessibility of guns made the world safer for him or
> anyone else?
>
> Tell me more about the blessing of firearms...
>
> About the freedom it brings...
>
> About safety and security...
>
> And how it limits the powers of the government...
>
> And how it protects from communists...
>
> Do you really believe in this?
>
> As a young engineer in So Cal I once met an older engineer, who did.
>
>
>
> Sincerely, Gregory from Oz
>
>
>
>
>

******* ****** ****** ****** ******* ****** ****** ********

Re: Gantry Crane Rail Blockout

Paul and Daryl et al,
I haven't said anything because every job is special and my solution may
not be appropriate. Given what Daryl said below, I designed a flat
plate bolted to a concrete slab on grade to minimize tripping and allow
cross trafffic by fork lifts. The customer also wanted a dirt free
rail. I used a 1/2" or 5/8" plate(memory fails me here) bolted with
expansion bolts with countersunk heads. As I designed the gantry, I
chose a large diameter and width, special plastic (nylon?) wheel.
Havent had any feed-back after approx 15 years. Sorry abt the
vagueness, but I designed it, but it was drawn by my customer.
Gary

Daryl Richardson wrote:
>
> You haven't indicated why you need a block-out. I'm
> speculating that you want to avoid a tripping hazard or provide some
> type of cross rail access for a vehicle or a dolly or some other
> wheeled transporter. If you can use the solid bar rail you can
> probably use a channel cast into the floor toes up (either a C or an
> MC shape) according to the depth you require. I'm sorry; I don't have
> a detail for a larger cast crane block-out.
>
> Hope this is helpful.
>
> Regards,
>
> H. Daryl Richardson
>
> ----- Original Message -----
> *From:* Paul Blomberg <mailto:paul.blomberg@gmail.com>
> *To:* seaint <mailto:seaint@seaint.org>
> *Sent:* Wednesday, April 18, 2007 4:56 PM
> *Subject:* Gantry Crane Rail Blockout
>
> I've got a client that wants to incorporate a 'future' 20 ton
> gantry crane into their manufacturing facility. I was envisioning
> a block out in the slab on ground that is removed and the rail set
> in the block out, leveled, plumbed and polyurethane fill cast
> around the rail to set it in place. This detail is used locally
> as part of the light rail commuter transit system.
>
> Others in my office are voting for an embedded plate in the bottom
> of the block out with the rail ultimately welded to the embed
> plate. My concern with this approach is alignment and elevation
> tolerance. I know from experience that embedded plates don't get
> the same close tolerances that a rail support needs. Also, with
> the future installation of the rail and crane, the General
> Contractor may not meet the strict tolerances for the rail and the
> owner might suffer later during rail installation.
>
> As another alternative I was thinking that I could use rail clamps
> and concrete anchors and shim to the proper elevation. I'm
> looking for your input and alternatives.
>
> Additionally, does anyone ever provide drainage in the annulus
> next to the rail. This gantry crane travels from outside the
> building into the building.
>
> Your thoughts are appreciated.
>
> Paul.
>

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Re: Masonry Skewed Shear Walls

Skewed Shear Walls
Break components of load acting on shear wall into perpendicular and
parallel loads.
for flexible diaphragm, load acts on wall by tributary area.
look at ACI 530 for out-of-plane loads, and in-plane shear wall loads
and analyze by the appropriate equations.

2007/4/20, Aldo Gonzales <allmin02@yahoo.es>:
> I'm working on a project with Masonry skewed shear
> walls and flexible diaphragm. Can someone help me with
> some example from some book, references to papers, or
> let me know how should I analyze it? I would
> appreciate any comments. Thanks.
>
>
>
> ____________________________________________________________________________________
> LLama Gratis a cualquier PC del Mundo.
> Llamadas a fijos y móviles desde 1 céntimo por minuto.
> http://es.voice.yahoo.com
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> * This email was sent to you via Structural Engineers
> * Association of Southern California (SEAOSC) server. To
> * subscribe (no fee) or UnSubscribe, please go to:
> *
> *

http://www.seaint.org/sealist1.asp
> *
> * Questions to seaint-ad@seaint.org. Remember, any email you
> * send to the list is public domain and may be re-posted
> * without your permission. Make sure you visit our web
> * site at: http://www.seaint.org
> ******* ****** ****** ****** ******* ****** ****** ********
>

Thursday, April 19, 2007

Re: Gantry Crane Rail Blockout

Ralph

I hear what you're saying, Ralph; but down time for a factory can be pretty expensive too. But it's the owner's money and he should be the one to decide whether or not to provide for a future crane.

I think what I would do in this case (with the owner's approval, of course) is construct a standard floor trench designed and supported to function as a foundation grade beam for the crane, provide a steel plate cover, and leave the rest to the future crane supplier to drill anchors as required for whatever crane rail slide plate detail they want to use to secure any reasonable ASCE rail size they might use.

Regards,

H. Daryl Richardson

----- Original Message -----

From: Rhkratzse@aol.com

To: paul.blomberg@gmail.com ; seaint@seaint.org

Sent: Thursday, April 19, 2007 4:29 PM

Subject: Re: Gantry Crane Rail Blockout

I don't mean this as any sort of criticism of anyone, but this discussion reminds me of a situation that occurred in a transit tunnel under downtown Seattle a few years ago: Planning for future light rail the designers embedded rails in the tunnel floor, even though initial use was only by buses. When the time came to activate the rails they were found to be inadequate (electrically, for signaling/control purposes IIRC), requiring multi-million-dollar replacement.

Ralph

In a message dated 4/19/07 2:45:06 PM, paul.blomberg@gmail.com writes:

Daryl,

Thanks for the information. I am specifying a 20 ton crane capacity and there will be worker and forklift traffic across the rail so I'm embedding the track. Unfortunately, it is a "future" gantry crane so we don't have an awarded supplier and the manufacturers are a little slow providing specific information if there is no sale in sight.

So I'm fishing for a generic block out detail that can be installed now and removed in the future and a gantry crane rail installed. All the discussion I get on the subject is good for me!

Paul.

On 4/19/07, Daryl Richardson <h.d.richardson@shaw.ca> wrote:
Paul,

        I have assessed, reviewed, and/or designed a few gantry cranes over the years. Following are a few thoughts that may (or may not) be helpful. You are welcome to the helpful ones.

        Your first considerations are probably the load rating and type of wheels you want to use. Some gantry cranes I have been involved with have been on castors, hence, they could be moved anywhere in the building even when they were loaded. No rails required! These have included cranes up to two ton rating.

        For intermediate cranes (say three ton to seven or possibly ten ton) you could consider using solid rubber wheels which do not require a rail but probably do require a dedicated runway location in order to have adequate foundation to avoid cracking the slab.

        For larger design loading, say above seven or ten ton, you will probably opt for a rail system. Whether you use a block-out or not is another question. this, of course brings up the question "do you use a solid bar for a rail or do you go to an actual ASCE rail?" This will affect what type of block-out, if any, you design.

        You haven't indicated why you need a block-out. I'm speculating that you want to avoid a tripping hazard or provide some type of cross rail access for a vehicle or a dolly or some other wheeled transporter. If you can use the solid bar rail you can probably use a channel cast into the floor toes up (either a C or an MC shape) according to the depth you require. I'm sorry; I don't have a detail for a larger cast crane block-out.

        Hope this is helpful.

Regards,

H. Daryl Richardson

**************************************
See what's free at http://www.aol.com.

Masonry Skewed Shear Walls

I'm working on a project with Masonry skewed shear
walls and flexible diaphragm. Can someone help me with
some example from some book, references to papers, or
let me know how should I analyze it? I would
appreciate any comments. Thanks.

____________________________________________________________________________________
LLama Gratis a cualquier PC del Mundo.
Llamadas a fijos y móviles desde 1 céntimo por minuto.

http://es.voice.yahoo.com

******* ****** ****** ****** ******* ****** ****** ********

Re: SHOOTINGS

RS,

I hope you do not base you engineering on chain letters as you have based the statistics quoted below.

http://www.breakthechain.org/exclusives/australiaguns.html gives a copy of the chain letter which contains these misquoted "statistics" and the real story as well.

For example the 300% increase in home robberies was actually supposed to be homicides in one state, from 7 to 19 in one year (not actually 300% but who cares about bad math if it helps the story). But that is the state in Australia that has the most organised crime problems and there were several tit-for-tat killings in those years. As the article commenting on the chain letter says

"An increase from 7 to 14 is only 100% and is hardly compelling. Population increase alone could account for the higher number. Regardless, in the United States - where most major cities have 7-14 homicides in a month - we would kill (pun intended) for crime rates that low. "

At 01:20 PM 20/04/2007, you wrote:

Australia's honest law abiding people surrendered all their fire arms as their government demanded approximately 2 years ago and last reports indicated that armed home robberies were up 300%. Guns don't kill people, people kill people and as long as it still takes 30 minutes or more for the police to respond to a breaking and entering, I am 100% behind the right to bear arms.

R.S.

----- Original Message -----

From: ASC

To: Struct EngAssoc

Sent: Tuesday, April 17, 2007 1:43 AM

Subject: SHOOTINGS

The rest of civilized world never ceases to be amazed

with America's love affair with guns.

And with America's unwillingness to do anything about it.

36,000 people are dying each year this way, most by accidents.

That deranged individual was not a criminal by design, was he?

Did the accessibility of guns made the world safer for him or anyone else?

Tell me more about the blessing of firearms...

About the freedom it brings...

About safety and security...

And how it limits the powers of the government...

And how it protects from communists...

Do you really believe in this?

As a young engineer in So Cal I once met an older engineer, who did.

Sincerely, Gregory from Oz

Regards Gil Brock
Prestressed Concrete Design Consultants Pty. Ltd. (ABN 84 003 163 586)
5 Cameron Street Beenleigh Qld 4207 Australia
Ph +61 7 3807 8022               Fax +61 7 3807 8422
email:            gil@raptsoftware.com
email:            sales@raptsoftware.com
email:            support@raptsoftware.com
webpage:         http://www.raptsoftware.com

Re: SHOOTINGS

Well stated Chris.

Ray Shreenan
----- Original Message -----
From: "Christopher Wright" <chrisw@skypoint.com>
To: <seaint@seaint.org>
Sent: Tuesday, April 17, 2007 10:14 AM
Subject: Re: SHOOTINGS

>
> On Apr 17, 2007, at 3:43 AM, ASC wrote:
>
>> The rest of civilized world never ceases to be amazed
>> with America's love affair with guns.
> I need to say this for a couple of reasons. First as a counterpoint
> to responses about constitutional rights and sophistry about how
> people kill people and guns don't kill people; second, to point out
> that America has no such love affair.
>
> Ssome Americans are indeed gun freaks, but don't lump the rest of us
> with the wackos. Historically, firearms have played an important,
> often ugly, part in life along our frontier. Most people (like my
> family, who were farmers) had them for hunting, and to a small degree
> for self-defense. As people moved west there wasn't any law,
> especially in the territories which had no government. There were
> plenty of criminals, ex-soldiers out of a job or just plain losers,
> westbound maybe just ahead of the law and who didn't mind taking
> whatever they wanted at gunpoint and who frequently took a shot at
> someone while nerved up on whiskey. And for better or worse there
> came Vigilance Committees formed to deal with the worst of them. As a
> result we built up a thriving firearms industry and a huge mythology
> which helps the firearms industry sell guns.
>
> Actually, some of the mythology is partly true, Northfield, Minnesota
> was hit in the 1880's by members of the Cole-Younger gang looking to
> knock over the bank. That was before the FDIC and if the bank were
> cleaned out, the town was done for. The townspeople fought back, not
> with personal firearms, but rifles borrowed from local stores, and
> shot up the gang pretty thoroughly. Two townspeople were killed, the
> head teller of the bank and a farmer who didn't speak english and
> couldn't understand the warnings to take cover. Except for two who
> were killed, the gang took off but were rounded up a few days later
> except for the James brothers who evaded capture. Real wild west
> stuff, but not typical. Northfield was home to a number of Civil War
> veterans who probably had no more of a love affair with guns than
> anyone else who'd seen the elephant.
>
> That said most Americans don't buy into the myths--there's no love
> affair. A great many Americans, probably a majority, feel horrified
> about loose gun laws. What we do have is too-easy access to guns,
> because some of the philosopher-kings in Congress have been rented by
> the gun lobby and because some people still truly believe their guns
> will hold off the US Army if they are beset by tyrants. The fact is
> that even easy access to guns alone doesn't make us all murderers. To
> its shame, Minnesota allows people to carry concealed hand guns,
> provided they have a permit which must be issued by local law
> enforcement after a background check and some (meaningless) safety
> training. But gun crimes haven't increased noticeably, because most
> people don't want to carry weapons. We still have plenty of
> accidental shootings and an unenviable murder rate, of course, but
> the cause isn't a love affair, it's accessibility.
>
> Which excuses nothing, of course, but it does help explain what
> actually goes into all this. Accessibility, not love affairs, lets
> losers and wackos, for whom guns imply power over their enemies, arm
> themselves. Whenever they feel slighted, such crazies think of the
> myths, and imagine themselves going out in a blaze of glory, as a
> winner, finally respected by everyone. That's not a love affair with
> guns, that's lunacy, probably not much different than the lunacy
> which drives suicide bombers.
>
> I went to school at VPI (that's the real name), and took plenty of
> classes in Holden, since it was the Engineering Mechanics building.
> Things have changed a lot, but I'm sure there were losers and gun
> freaks around then, too. There were plenty of things wrong back
> around 1960, but just as now, an excess of self-righteousness won't
> fix it. So cut us some slack.
>
> Christopher Wright P.E. |"They couldn't hit an elephant at
> chrisw@skypoint.com | this distance" (last words of Gen.
> .......................................| John Sedgwick, Spotsylvania
> 1864)
> http://www.skypoint.com/~chrisw/
>
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> * This email was sent to you via Structural Engineers
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Re: SHOOTINGS

Australia's honest law abiding people surrendered all their fire arms as their government demanded approximately 2 years ago and last reports indicated that armed home robberies were up 300%. Guns don't kill people, people kill people and as long as it still takes 30 minutes or more for the police to respond to a breaking and entering, I am 100% behind the right to bear arms.

R.S.

----- Original Message -----

From: ASC

To: Struct EngAssoc

Sent: Tuesday, April 17, 2007 1:43 AM

Subject: SHOOTINGS

The rest of civilized world never ceases to be amazed

with America's love affair with guns.

And with America's unwillingness to do anything about it.

36,000 people are dying each year this way, most by accidents.

That deranged individual was not a criminal by design, was he?

Did the accessibility of guns made the world safer for him or anyone else?

Tell me more about the blessing of firearms...

About the freedom it brings...

About safety and security...

And how it limits the powers of the government...

And how it protects from communists...

Do you really believe in this?

As a young engineer in So Cal I once met an older engineer, who did.

Sincerely, Gregory from Oz

Re: Gantry Crane Rail Blockout

I don't mean this as any sort of criticism of anyone, but this discussion reminds me of a situation that occurred in a transit tunnel under downtown Seattle a few years ago: Planning for future light rail the designers embedded rails in the tunnel floor, even though initial use was only by buses. When the time came to activate the rails they were found to be inadequate (electrically, for signaling/control purposes IIRC), requiring multi-million-dollar replacement.

Ralph

In a message dated 4/19/07 2:45:06 PM, paul.blomberg@gmail.com writes:

Daryl,

Thanks for the information. I am specifying a 20 ton crane capacity and there will be worker and forklift traffic across the rail so I'm embedding the track. Unfortunately, it is a "future" gantry crane so we don't have an awarded supplier and the manufacturers are a little slow providing specific information if there is no sale in sight.

So I'm fishing for a generic block out detail that can be installed now and removed in the future and a gantry crane rail installed. All the discussion I get on the subject is good for me!

Paul.

On 4/19/07, Daryl Richardson <h.d.richardson@shaw.ca> wrote:
Paul,

        I have assessed, reviewed, and/or designed a few gantry cranes over the years. Following are a few thoughts that may (or may not) be helpful. You are welcome to the helpful ones.

        Your first considerations are probably the load rating and type of wheels you want to use. Some gantry cranes I have been involved with have been on castors, hence, they could be moved anywhere in the building even when they were loaded. No rails required! These have included cranes up to two ton rating.

        For intermediate cranes (say three ton to seven or possibly ten ton) you could consider using solid rubber wheels which do not require a rail but probably do require a dedicated runway location in order to have adequate foundation to avoid cracking the slab.

        For larger design loading, say above seven or ten ton, you will probably opt for a rail system. Whether you use a block-out or not is another question. this, of course brings up the question "do you use a solid bar for a rail or do you go to an actual ASCE rail?" This will affect what type of block-out, if any, you design.

        You haven't indicated why you need a block-out. I'm speculating that you want to avoid a tripping hazard or provide some type of cross rail access for a vehicle or a dolly or some other wheeled transporter. If you can use the solid bar rail you can probably use a channel cast into the floor toes up (either a C or an MC shape) according to the depth you require. I'm sorry; I don't have a detail for a larger cast crane block-out.

        Hope this is helpful.

Regards,

H. Daryl Richardson

**************************************
See what's free at http://www.aol.com.

Re: VIRGINIA TECH

David-

You missed Ralph's point. Re-read his comment.

Regards,

Bill Cain SE

Berkeley CA

-----Original Message-----
From: dfisher@fpse.com
To: seaint@seaint.org
Sent: Thu, 19 Apr 2007 12:24 PM
Subject: RE: VIRGINIA TECH

How about settled on the golf course or at a cocktail party?

David L. Fisher SE PE

Senior Director

Cape Cod Grand Cayman Holdings Ltd. - Cayman

Fisher+Partners Structural Engineers Ltd. - Cayman

980 North Michigan Avenue #1640 Chicago 60611

75 Fort Street Georgetown Grand Cayman BWI

319 A Street Boston 02210

312.573.1701

312.573.1726 facsimile

312.622.0409 mobile

www.ccgch.com

www.fpse.com

From: Rhkratzse@aol.com [mailto:Rhkratzse@aol.com]
Sent: Thursday, April 19, 2007 2:22 PM
To: cbanbury@arkengineering.net; seaint@seaint.org
Subject: Re: VIRGINIA TECH

But surely not only there. Sometimes bigger "debates" are required, as at the Boston Tea Party, and in the late '60s.

Ralph

In a message dated 4/19/07 7:22:02 AM, cbanbury@arkengineering.net writes:

Politics should be debated over coffee between two individuals who have a mutual respect for one another.

**************************************
See what's free at http://www.aol.com.

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Re: Gantry Crane Rail Blockout

Daryl,

Thanks for the information. I am specifying a 20 ton crane capacity and there will be worker and forklift traffic across the rail so I'm embedding the track. Unfortunately, it is a "future" gantry crane so we don't have an awarded supplier and the manufacturers are a little slow providing specific information if there is no sale in sight.

So I'm fishing for a generic block out detail that can be installed now and removed in the future and a gantry crane rail installed. All the discussion I get on the subject is good for me!

Paul.

On 4/19/07, Daryl Richardson <h.d.richardson@shaw.ca> wrote:

Paul,

        I have assessed, reviewed, and/or designed a few gantry cranes over the years. Following are a few thoughts that may (or may not) be helpful. You are welcome to the helpful ones.

        Your first considerations are probably the load rating and type of wheels you want to use. Some gantry cranes I have been involved with have been on castors, hence, they could be moved anywhere in the building even when they were loaded. No rails required! These have included cranes up to two ton rating.

        For intermediate cranes (say three ton to seven or possibly ten ton) you could consider using solid rubber wheels which do not require a rail but probably do require a dedicated runway location in order to have adequate foundation to avoid cracking the slab.

        For larger design loading, say above seven or ten ton, you will probably opt for a rail system. Whether you use a block-out or not is another question. this, of course brings up the question "do you use a solid bar for a rail or do you go to an actual ASCE rail?" This will affect what type of block-out, if any, you design.

        You haven't indicated why you need a block-out. I'm speculating that you want to avoid a tripping hazard or provide some type of cross rail access for a vehicle or a dolly or some other wheeled transporter. If you can use the solid bar rail you can probably use a channel cast into the floor toes up (either a C or an MC shape) according to the depth you require. I'm sorry; I don't have a detail for a larger cast crane block-out.

        Hope this is helpful.

Regards,

H. Daryl Richardson

NOW: Political debates

I liken those venues to the smoky back rooms where the elites have traditionally made policy for the country, as opposed to the more democratic locations like the halls of Congress and, yes, boats in Boston harbor, and the streets.

Ralph

In a message dated 4/19/07 12:27:35 PM, dfisher@fpse.com writes:

How about settled on the golf course or at a cocktail party?

**************************************
See what's free at http://www.aol.com.

RE: VIRGINIA TECH

How about settled on the golf course or at a cocktail party?

David L. Fisher SE PE

Senior Director

Cape Cod Grand Cayman Holdings Ltd. - Cayman

Fisher+Partners Structural Engineers Ltd. - Cayman

980 North Michigan Avenue #1640 Chicago 60611

75 Fort Street Georgetown Grand Cayman BWI

319 A Street Boston 02210

312.573.1701

312.573.1726 facsimile

312.622.0409 mobile

www.ccgch.com

www.fpse.com

From: Rhkratzse@aol.com [mailto:Rhkratzse@aol.com]
Sent: Thursday, April 19, 2007 2:22 PM
To: cbanbury@arkengineering.net; seaint@seaint.org
Subject: Re: VIRGINIA TECH

Politics should be debated over coffee between two individuals who have a mutual respect for one another.

**************************************
See what's free at http://www.aol.com.

Re: VIRGINIA TECH

Politics should be debated over coffee between two individuals who have a mutual respect for one another.

**************************************
See what's free at http://www.aol.com.

Re: Gantry Crane Rail Blockout

Paul,

I have assessed, reviewed, and/or designed a few gantry cranes over the years. Following are a few thoughts that may (or may not) be helpful. You are welcome to the helpful ones.

Your first considerations are probably the load rating and type of wheels you want to use. Some gantry cranes I have been involved with have been on castors, hence, they could be moved anywhere in the building even when they were loaded. No rails required! These have included cranes up to two ton rating.

For intermediate cranes (say three ton to seven or possibly ten ton) you could consider using solid rubber wheels which do not require a rail but probably do require a dedicated runway location in order to have adequate foundation to avoid cracking the slab.

For larger design loading, say above seven or ten ton, you will probably opt for a rail system. Whether you use a block-out or not is another question. this, of course brings up the question "do you use a solid bar for a rail or do you go to an actual ASCE rail?" This will affect what type of block-out, if any, you design.

You haven't indicated why you need a block-out. I'm speculating that you want to avoid a tripping hazard or provide some type of cross rail access for a vehicle or a dolly or some other wheeled transporter. If you can use the solid bar rail you can probably use a channel cast into the floor toes up (either a C or an MC shape) according to the depth you require. I'm sorry; I don't have a detail for a larger cast crane block-out.

Hope this is helpful.

Regards,

H. Daryl Richardson

----- Original Message -----

From: Paul Blomberg

To: seaint

Sent: Wednesday, April 18, 2007 4:56 PM

Subject: Gantry Crane Rail Blockout

I've got a client that wants to incorporate a 'future' 20 ton gantry crane into their manufacturing facility. I was envisioning a block out in the slab on ground that is removed and the rail set in the block out, leveled, plumbed and polyurethane fill cast around the rail to set it in place. This detail is used locally as part of the light rail commuter transit system.

Others in my office are voting for an embedded plate in the bottom of the block out with the rail ultimately welded to the embed plate. My concern with this approach is alignment and elevation tolerance. I know from experience that embedded plates don't get the same close tolerances that a rail support needs. Also, with the future installation of the rail and crane, the General Contractor may not meet the strict tolerances for the rail and the owner might suffer later during rail installation.

As another alternative I was thinking that I could use rail clamps and concrete anchors and shim to the proper elevation. I'm looking for your input and alternatives.

Additionally, does anyone ever provide drainage in the annulus next to the rail. This gantry crane travels from outside the building into the building.

Your thoughts are appreciated.

Paul.

Re:Steel Member CB150

This is an old historic shape. You can use the AISC database at the following link to look it up:

http://www.aisc.org/Content/NavigationMenu/ePubs/ePubs_Home/AISC_Shapes_Database/AISC_Shapes_Database.htm

I could not find a CB150 but a CB151 was noted - it is a wide flange of 15 inches deep.

Hope this helps.

- Ashwin
------------------------------------
Aswin Ranga Swamy, P.E.
Los Angeles, California
------------------------------------

----- Original Message -----

From: j.n.sigalas

To: seaint@seaint.org

Sent: Friday, April 20, 2007 2:12 PM

fellow list members

looking in the drawings of an old r/r bridge I saw some steel members

marked as CB150 without any other info.

any ideas on what this mark means?

regards

j.n.sigalas

RE: Converting PLT files or AutoCad output to TIFF format

You might want to check out the AUGI website and see if the answer can be found there. http://www.augi.com

From: Jun Navaro [mailto:j.navaro@lycos.com]
Sent: Thursday, April 19, 2007 7:48 AM
To: seaint@seaint.org
Subject: Re: Converting PLT files or AutoCad output to TIFF format

hI!

I want my drawing in autocad transferred into a shape file. can anybody knows

thanks.

jun

---------[ Received Mail Content ]----------

Subject : Re: Converting PLT files or AutoCad output to TIFF format

Date : Wed, 18 Apr 2007 09:35:10 -0700 (PDT)

From : Mark Johnson <markajohn@yahoo.com>

To : seaint@seaint.org

Dennis,

Here is a late response, but better late than never.

I have used a thing called "Infomatik image driver" to

make TIFF files. Not free, but not too expensive.

I think most of the printers around here charge the

same for PDF as for TIFF so I use "Cutepdf Writer" to

create PDFs, and it's free, not shareware.

HTH

MJ

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Re: Converting PLT files or AutoCad output to TIFF format

hI!

I want my drawing in autocad transferred into a shape file. can anybody knows

thanks.

jun

---------[ Received Mail Content ]----------

Subject : Re: Converting PLT files or AutoCad output to TIFF format

Date : Wed, 18 Apr 2007 09:35:10 -0700 (PDT)

From : Mark Johnson <markajohn@yahoo.com>

To : seaint@seaint.org

Dennis,

Here is a late response, but better late than never.

I have used a thing called "Infomatik image driver" to

make TIFF files. Not free, but not too expensive.

I think most of the printers around here charge the

same for PDF as for TIFF so I use "Cutepdf Writer" to

create PDFs, and it's free, not shareware.

HTH

MJ

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* Read list FAQ at: http://www.seaint.org/list_FAQ.asp

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* This email was sent to you via Structural Engineers

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RE: VIRGINIA TECH

GfO,

I apologize for snapping at you.

I rely on the structural experience and technical advice of SEAINT list members.

It would be unfortunate if sound advice went unheeded because of personal prejudice against another’s politics.

I think that is why moderation is important to the future success of this list.

Politics should be debated over coffee between two individuals who have a mutual respect for one another.

Regards,

Christopher Banbury, PE

President

Ark Engineering, Inc.

PO Box 10129, Brooksville, FL 34603

22 N. Broad ST, Brooksville, FL 34601

Phone: (352) 754-2424

FAX: (352) 754-2412

www.arkengineering.net

RE: Virginia Tech

REPLY
April 19, 2007

Just as a quick reply, CNN reported that the Police had reason to focus
their attention on the boyfriend of the girl killed in the dorm prior to the
shooting in the engineering department. The boy had guns on campus
previously and photos were shown of him target shooting with the girl that
was killed. The police acted appropriately to focus on the boyfriend and to
seek the young man who was helpful in their investigation. Unfortunately,
while this was happening, the young man who fired upon the dorm was on his
way to the engineering department to create the havoc and killings that were
reported. I would not hold the police or the University with responsibility
based on the lack of manpower and the strong leads that it was an isolated
incidents responsible for failing to respond.
I understand Jordan's comments, but I don't think my comments were based on
anger or intended to point blame. Every news outlet is handling some sort of
speculation on what has happened and all I wanted to do was to bring the
discussion to the surface while it was fresh in everyone's mind. I expect
that the media will polute the information as much as possible in the next
few weeks, but the basic issue of gun "control" rather "elimination" is the
root of the issue. I don't believe this event was an anomoly following the
reports of the killers methodical plan and the mailing of the video
manifesto he sent to NBC that was released today. Even this event is not
unique in the overall discussion that seems to be as difficult as
discussions of politics, religion or sexuality in this country. As engineers
we should be able to provide useful suggestions as how to make weapons such
as guns safe in our society using physical methods rather than relying upon
information databases to control the sale and permitting. I saw a commercial
the other day for Volvo that provided a sensor on the keychain door lock
that could alert the driver through sensors within the car if there was a
heart beat detected in the automobile so that the driver does not enter if
the presence of another human being is not expected.
Why is it so hard to discuss these issues without some on making it a
political statement? If you did not know me, then nothing in my posts would
point to political leanings except on comment I made about being liberal
leaning and even this was stated in such a way as to dismiss the idea that I
was speaking from a political view.
I don't feel I have a bias here any more than if I was discussing how to
deal with the design of automobiles to prevent someone with a high alchol
level from engaging the ignition.
Please don't feel that originates from a horrible tragedy, but rather that
the event being fresh in our memories keeps people focused on mitigating a
threat while motivated to do so. I've never intended to attack the gun
lobby, but to look at the mechanism and to develop some additional safety
mechanisms that can help reduce the number of accidents or worse, the
ability to fire by one who ones a gun based on bio signs or heart and stress
related sensors. I'm sure there are more technology already available that
can be engaged that may assist gun manufacturers in providing a responsible
solution to the problem and what better audience to discuss this with but
intelligent engineers.

I promise not to pose further questions and apologize if, in fact, I have
insulted anyone - it was not my intent to do so.

Dennis S. Wish, PE
California Professional Engineer
Structural Engineering Consultant
C-41250 (Exp. 3/31/09)
dennis.wish@verizon.net
http://structuralist.spaces.live.com

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-----Original Message-----
From: Jordan Truesdell, PE [mailto:seaint1@truesdellengineering.com]
Sent: Wednesday, April 18, 2007 4:59 AM
To: seaint@seaint.org
Subject: Virginia Tech

Thank you to everyone on the list who has expressed their sympathies
over the shootings at Virginia Tech. It has been a combination of grief
and insanity here the last couple of days. Most of the people I know
have been on the net - trying to get information on what has happened,
if friends or loved ones were involved, finding out what will be
happening over the next days and weeks. We have also had to defend the
actions of our president and police force, and I have never been so
disappointed in the media. The whole community will be relieved when the
spotlight is turned off.

I did not know any of the victims personally, though I knew of some of
them. As you may know, one of the classes involved was a graduate class
in Civil Engineering, and the professor and at least four of the
students are known to be dead. I have not spoken to anyone at Virginia
Tech in the CEE department except a student who was helping me on a
small project, and only briefly. I'm certain they have been inundated
with emails and phone calls; I do not need to add to that burden. At
least one of the professors lived in my small neighborhood on the south
side of town.

Please do not use this to frame the firearms debate, for or against.
Here in Blacksburg, arguments from all sides ring hollow in the
aftermath of the loss we have suffered. Please take your anger and
posturing elsewhere. If you should have a chance, there is a rebroadcast
of the convocation held at Tech on hokiesports.com, and I suspect it
will be on youtube in fairly short order. The words spoken there were
timely and heartfelt. It is difficult to condense the range of emotions
and feelings into a single hour, but I believe that is exactly what was
done yesterday.

Again, many thanks to all who have offered their support over the past
couple of days.

Jordan Truesdell, PE
Virginia Tech Aerospace & Ocean Engineering
Class of 1992

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Re: Gantry Crane Rail Blockout

Paul,

The millwrights that install the “future” gantry crane rails know how to shim and level the rails.

I have had no experience with a gantry crane, but I would include a drain to keep rain from flowing into the building.

Jim Getaz

Winchester, Virginia

Re: Copying sealed PE work for personal records

That would be trademark. ;-)

Jordan

Christopher Wright wrote:
> <snip>
> To risk putting words in your mouth i wonder if you might have meant
> "a system where added value is not necessary, and the simple act of
> branding is sufficient."

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