Structural Engineering: 2008-06-15

Saturday, June 21, 2008

Re: I'm I just a small thinker?

No, I think you are perfectly correct to find it overly expensive. The original notification I received stated that the seminar will be 45 minutes to one hour long -- and this webinar covers the three story wood building example in volume two of the design manuals. Not to point any fingers, but why do we need a seminar on a design example? Could it be that the examples are not worked out in enough detail to make it self explanatory?

First they take us for the design manuals that are full of errors and then they take us for the seminars.

By the way, there is a seminar offered on anchors in concrete for $295. What is going on here? Just charge the captive audience to educate them on the codes you helped write. This is just my opinion.

Andrew Vidikan, PE
Los Angeles

-----Original Message-----
From: Bill Allen <t.w.allen@cox.net>
To: Seaint <seaint@seaint.org>
Sent: Fri, 20 Jun 2008 9:24 pm
Subject: I'm I just a small thinker?

Or does anyone else think it is ludicrous to charge $250 for a webinar connection?

I'm referring to http://ncsea.com/. Don't get me wrong; I think Doug Thompson is a fine speaker and the topic should be interesting.

But $250 and not even a continental breakfast?

Is it just me?

T. William (Bill) Allen, S.E.

ALLEN DESIGNS

Consulting Structural Engineers
V (949) 248-8588 • F(949) 209-2509

Get the Moviefone Toolbar. Showtimes, theaters, movie news, & more!

RE: WA SE III Exam

This all assumes that it has NOT changed since I took it roughly 4 years ago the last time...

It is essay (i.e. long hand calculations with partial credit). It is an 8 hour exam. There are 4 problems to do...two in the morning and two in the afternoon. In each session, if I recall correctly, there are three problems...one that you have to do and the second is a choice between a bridge and building problem...but both could be a choice between a bridge and building problem...I just don't recall for sure. I do know that you DO NOT have to do bridge problems if you don't want (i.e. they are optional).

I don't know how close it is to the new CA SE III format as I have not taken the CA SE III and now that CA accepts the WA SE for reciprocity, it looks like I never will if I want my SE in CA. I would suspect that it is rather similar.

I am not aware of any study guides, but there might be some.

It makes the Struct II exam look easy...at least compared to how the Struct II exam was when I took it. And it makes the Struct I exam look like a complete joke (as well as the Civil PE exam).

My best advice, study and know all four major materials. Every time (third time was the charm...but then I am never too fond of studying and did not study much...besides, if you get to do well rounded design...i.e. all materials and wind and seismic...on a regular basis, then should be in pretty good shape without studying) I took the exam, all four materials were covered each time. Know the wind provisions and the seismic provisions...you WILL get a problem on each at least. Time is definitely a factor, so make sure you know where stuff is and don't have to waste too much time looking it up. You can bring books and codes, so you can bring textbooks and such as "crutches", but if you have to use them too much, then you are likely dead.

Good luck. Let me know if you have any more questions and I will see if I can answer them.

Regards,

Scott

Adrian, MI

-----Original Message-----
From: Jake Watson [mailto:jake.watson1@gmail.com]
Sent: Saturday, June 21, 2008 4:53 PM
To: SEAINT
Subject: WA SE III Exam

I am looking into taking the Washington SE III Exam. The exam program on WA's website is very generic and of little help. I have tried looking for a study guide or other references which may shed some light on it. So far, I have come up empty. Can anyone shed some light on this exam? What is the format (essay, multiple choice, a mixture)? Are sample or past exams available? Bridge codes are listed in the program. Is bridge content compulsory or optional? Are there study guides available that I simply can't find? How close is it to the new CA SE III format?

Thanks,
Jake Watson, SE
Salt Lake City, UT

Re: Residential Foundation Tipping

Dave,

I presume the house has a large aspect ratio; say 2:1 or greater, and there is a vertical crack in the basement wall near the center, or between beam points if the joists run parallel, and diagonal cracks in the corners? (If not, I've misread your post...and you can ignore the rest) The footing has almost zero resistance to rotation, of course, but given a typical FS of 2.5 to 3.0 on soils data, and the likelihood that the site was excavated and re-filled (a possible 9'x110psf of overburden compression which may not have completely relaxed if it is clay), you could see as much as 5000-6000psf before failure instead of a prescriptive 1500psf (geo may have like given 2500-3000 given the report uscs).

I've seen a couple of cases where the floor just couldn't handle the load at the top of the wall. In one case, the band joist started to roll inward, in others it appeared that the bolt/concrete interface failed. I don't remember a concrete break-out, but with brick veneer you might not see it. In one I'm thinking of, the center of the basement wall bowed in about an inch, actually leaving the brick in place. The brick slipped at the concrete ledge, held in place by the wall above.

It's not too hard to show a failure on paper. With the most non-conservative clay backfill, you'd be close to 800plf at the sill plate interface, and with code levels something like 1200. Around here (low seismic and wind), houses get 1/2" bent anchors at 6' on center whether they need them or not ;-) Put a layer of sill sealing foam and you can kiss most of your friction interface goodbye. I keep wanting a floor diaphragm to fail just to say "I told you so," but between the drywall and the nails they use for temporary support it just doesn't fail as often as it should.

The walls I've seen haven't been really bad, so we haven't done a full up mitigation. Tie backs are one solution, and replacing the backfill with stone might not be a bad idea (and may simplify the tie back design significantly).

Good luck...let us know how it turns out.

Jordan

David Maynard wrote:

Got this call earlier this week. Like to hear what everyone has to say.

It’s a residential foundation, 9’-3” wall on top of 8” by 16” continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it’s a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE

Gillette, WY

WA SE III Exam

I am looking into taking the Washington SE III Exam. The exam program on WA's website is very generic and of little help. I have tried looking for a study guide or other references which may shed some light on it. So far, I have come up empty. Can anyone shed some light on this exam? What is the format (essay, multiple choice, a mixture)? Are sample or past exams available? Bridge codes are listed in the program. Is bridge content compulsory or optional? Are there study guides available that I simply can't find? How close is it to the new CA SE III format?

Thanks,
Jake Watson, SE
Salt Lake City, UT

Saving Our Historic Buildings

Fellow engineers,

As all of you know, saving our historically significant buildings is an always difficult and often impossible task. As some of you will recall, my son, Neil, and I have been dedicating ourselves to saving at least some of the buildings in Southern Alberta in recent years. In so doing I have posted a number of questions on this list asking for, and receiving, valuable help in achieving our goals. I, therefore, thought that I would like to bring you up to date on just what we have been able to accomplish; and to offer my thanks for the help you have provided over the years.

On June 7, we had a "Grand Opening and Block Party" in celebration of the (near) completion of the Lougheed Building. In the two weeks since we have also gotten our web site up and running. This web site is located at www.heritageproperty.ca . Please feel free to visit the site.

Again, thanks for the help you have provided over the years.

Regards,

H. Daryl Richardson

Re: I'm I just a small thinker?

Bill,

I hate to say this, but it is just you.

Consider you are actually saving money by not driving there.

V. Steve Gordin, SE
Irvine CA

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

From: Bill Allen

To: Seaint

Sent: Friday, June 20, 2008 21:24

Subject: I'm I just a small thinker?

Or does anyone else think it is ludicrous to charge $250 for a webinar connection?

I'm referring to http://ncsea.com/. Don't get me wrong; I think Doug Thompson is a fine speaker and the topic should be interesting.

But $250 and not even a continental breakfast?

Is it just me?

T. William (Bill) Allen, S.E.

ALLEN DESIGNS

Consulting Structural Engineers
V (949) 248-8588 • F(949) 209-2509

Friday, June 20, 2008

I'm I just a small thinker?

Or does anyone else think it is ludicrous to charge $250 for a webinar connection?

I’m referring to http://ncsea.com/. Don’t get me wrong; I think Doug Thompson is a fine speaker and the topic should be interesting.

But $250 and not even a continental breakfast?

Is it just me?

T. William (Bill) Allen, S.E.

ALLEN DESIGNS

Consulting Structural Engineers
V (949) 248-8588 • F(949) 209-2509

RE: Flat Slab Punching Shear Reinf.

I will see what I can dig up and get back to you if I find out anything of
interest.

Regards,

Scott
Adrian, MI

-----Original Message-----
From: William Haynes [mailto:gtg740p@gmail.com]
Sent: Friday, June 20, 2008 6:47 PM
To: seaint@seaint.org
Subject: Re: Flat Slab Punching Shear Reinf.

I've left the office now so I can't tell you exactly how long they are, but
if I remember right they are around 6 ft total length. They are called out
as "shear bars". For example, they call for (4)-#3 shear bars each way over
the top of the columns. They are in addition to the longitudinal column
strip moment resisting bars. The 45 degree segment of the "shear bars" fall
in the area of where a punching shear failure would occur.

The slab system I am analyzing has approximately 20 ft square bays so the
shear bars are a good bit shorter.

On Fri, Jun 20, 2008 at 5:38 PM, Scott Maxwell <smaxwell@umich.edu> wrote:
> Are they specifically called out as "shear bars"? How long are
> they...the middle section as well as the end sections? That shape
> looks like standard shapes used for flexural bars (i.e. at the top for
> negative moments at the supports and at the bottom for positive
> moments in midspan). Your implication is that they are relatively
> short bars JUST at the column, but it is not 100% clear if that is
> really the case.
>
> In response to your question...I honestly don't know if they are
> "acceptable". It could somewhat depend on the shape/length of the
> bar. In theory, if the 45 deg slope portion feel at the right place,
> it could resist shear at a shear crack.
>
> If you clarify, I might be able to see what I can find out from my
> sources.
>
> Regards,
>
> Scott
> Adrian, MI
>
> -----Original Message-----
> From: William Haynes [mailto:gtg740p@gmail.com]
> Sent: Friday, June 20, 2008 4:13 PM
> To: seaint@seaint.org
> Subject: Flat Slab Punching Shear Reinf.
>
>
> I am analyzing an existing slab for a change in occupancy load. The
> drawings are about 40 years old and have a 9" thick flat slab with 15"
> square columns. Over the columns they call for shear bars that are
> bent longitudinal bars but there are not any stirrups. The "shear
> bars" called for look something like this ______/========\______.
>
>
> I think I have seen bent bars like these in concrete joists to resist
> shear in older drawings before. In my case, they are straight at the
> bottom, then bend upwards at 45 degrees, are flat along the top over
> the column, then bend down at 45 degrees and are straight again along
> the bottom of the slab.
>
> Can you use bars like this under ACI today to resist punching shear in
> a flat slab? ACI talks about longitudinal bars AND stirrups but the
> shear bars they call for on these drawings are just several bent bars
> like I described over the columns.
>
>
> WH
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * 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
> ******* ****** ****** ****** ******* ****** ****** ********
>
>
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * 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:
> *
> *

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

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

Re: Flat Slab Punching Shear Reinf.

I've left the office now so I can't tell you exactly how long they
are, but if I remember right they are around 6 ft total length. They
are called out as "shear bars". For example, they call for (4)-#3
shear bars each way over the top of the columns. They are in addition
to the longitudinal column strip moment resisting bars. The 45 degree
segment of the "shear bars" fall in the area of where a punching shear
failure would occur.

The slab system I am analyzing has approximately 20 ft square bays so
the shear bars are a good bit shorter.

On Fri, Jun 20, 2008 at 5:38 PM, Scott Maxwell <smaxwell@umich.edu> wrote:
> Are they specifically called out as "shear bars"? How long are they...the
> middle section as well as the end sections? That shape looks like standard
> shapes used for flexural bars (i.e. at the top for negative moments at the
> supports and at the bottom for positive moments in midspan). Your
> implication is that they are relatively short bars JUST at the column, but
> it is not 100% clear if that is really the case.
>
> In response to your question...I honestly don't know if they are
> "acceptable". It could somewhat depend on the shape/length of the bar. In
> theory, if the 45 deg slope portion feel at the right place, it could resist
> shear at a shear crack.
>
> If you clarify, I might be able to see what I can find out from my sources.
>
> Regards,
>
> Scott
> Adrian, MI
>
> -----Original Message-----
> From: William Haynes [mailto:gtg740p@gmail.com]
> Sent: Friday, June 20, 2008 4:13 PM
> To: seaint@seaint.org
> Subject: Flat Slab Punching Shear Reinf.
>
>
> I am analyzing an existing slab for a change in occupancy load. The drawings
> are about 40 years old and have a 9" thick flat slab with 15" square
> columns. Over the columns they call for shear bars that are bent
> longitudinal bars but there are not any stirrups. The "shear
> bars" called for look something like this ______/========\______.
>
>
> I think I have seen bent bars like these in concrete joists to resist shear
> in older drawings before. In my case, they are straight at the bottom, then
> bend upwards at 45 degrees, are flat along the top over the column, then
> bend down at 45 degrees and are straight again along the bottom of the slab.
>
> Can you use bars like this under ACI today to resist punching shear in a
> flat slab? ACI talks about longitudinal bars AND stirrups but the shear bars
> they call for on these drawings are just several bent bars like I described
> over the columns.
>
>
> WH
>
> ******* ****** ******* ******** ******* ******* ******* ***
> * 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:
> *
> *

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

RE: Flat Slab Punching Shear Reinf.

Are they specifically called out as "shear bars"? How long are they...the
middle section as well as the end sections? That shape looks like standard
shapes used for flexural bars (i.e. at the top for negative moments at the
supports and at the bottom for positive moments in midspan). Your
implication is that they are relatively short bars JUST at the column, but
it is not 100% clear if that is really the case.

In response to your question...I honestly don't know if they are
"acceptable". It could somewhat depend on the shape/length of the bar. In
theory, if the 45 deg slope portion feel at the right place, it could resist
shear at a shear crack.

If you clarify, I might be able to see what I can find out from my sources.

Regards,

Scott
Adrian, MI

-----Original Message-----
From: William Haynes [mailto:gtg740p@gmail.com]
Sent: Friday, June 20, 2008 4:13 PM
To: seaint@seaint.org
Subject: Flat Slab Punching Shear Reinf.

I am analyzing an existing slab for a change in occupancy load. The drawings
are about 40 years old and have a 9" thick flat slab with 15" square
columns. Over the columns they call for shear bars that are bent
longitudinal bars but there are not any stirrups. The "shear
bars" called for look something like this ______/========\______.

I think I have seen bent bars like these in concrete joists to resist shear
in older drawings before. In my case, they are straight at the bottom, then
bend upwards at 45 degrees, are flat along the top over the column, then
bend down at 45 degrees and are straight again along the bottom of the slab.

Can you use bars like this under ACI today to resist punching shear in a
flat slab? ACI talks about longitudinal bars AND stirrups but the shear bars
they call for on these drawings are just several bent bars like I described
over the columns.

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

RE: Residential Foundation Tipping

I would agree.

My question would be is there signs of continuous movement or has it been this way for some time?

It is possible that the at rest pressure overwhelmed the connection to the top of the wall, but it stopped as the at rest pressures "retreated" active pressure levels when the wall moved. It could still fail as the soils reconsolidates overtime and goes back to an at rest pressure level and pushes it further.

Things like drainage (proper draining soil against the wall down to decent drain tile) and water table level and general soil moisture level at the wall due to rain can also have a dramatic effect. Also is there a possible surcharge load (i.e. can something heavy be places on the ground near the wall such as a heavy vehicle).

Regards,

Scott

Adrain, MI

-----Original Message-----
From: Steve Gordin [mailto:sgordin@sgeconsulting.com]
Sent: Friday, June 20, 2008 2:54 PM
To: Seaint
Subject: Re: Residential Foundation Tipping

Terek,

As bad as it looks, it still may work, provided the slab is present. There is somehting else here, too.

The inward rotation of the wall points more to the floor at its top giving way than to the inadequacy of the foundation.

V. Steve Gordin, SE
Irvine CA
----- Original Message -----

From: Tarek Mokhtar

To: seaint@seaint.org

Sent: Friday, June 20, 2008 11:41

Subject: Re: Residential Foundation Tipping

Dave,

I do not think an 8" x 16" "footer" works for a 9' tall retaining wall

Tarek Mokhtar, SE

Laguna Beach

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)

--

RE: Federal Project - Seismic Question

The soil type (i.e. Site Class) can have BIG impact. In the IBC world, "bad" soils can bump you from a low seismic (such as SDC B) to a moderate seismic risk (SDC C or even D for an important building like a hospital) even in area of low seismicity. Seismic evaluation in things like FEMA 310, the NEHRP provisions, the IBC and ASCE 7 are NOT just based upon seismicity of the region...but also importance of the building and site classification. Based upon the general soil description (i.e. mainly sandy soil on limestone), it kind sounds like a site class C to me...maybe at worst D.

The fact that Florida excludes seismic design in the Florida Building Code is meaningless. It is purely an administrative decision that seismic is not enough of concern to make people design for it. Does not mean that strictly speaking all areas of Florida have the same seismic risk OR that seismic risk is not possible at all. Just means that they decided that it was not a significant enough of a risk to warrant dealing with. The feds don't tend to take that belief no matter WHERE their buildings are....but then they are putting in place methods and procedures for use in ALL areas of the country whether there is a perceived seismic risk or not.

Regards,

Scott

Adrian, MI

-----Original Message-----
From: Andrew Kester, P.E. [mailto:akester@cfl.rr.com]
Sent: Friday, June 20, 2008 12:19 PM
To: seaint
Cc: Scott Maxwell
Subject: Federal Project - Seismic Question

I have a potential client asking for a Life Safety Performance Level building certification, it looks to be a Tier 1 according to ICSSC RP 6. This is detailed in FEMA 310. The project is assumed to be near Orlando, FL.

I have followed through the FEMA 310 formulas, they are rather simple, and have come up with a Moderate Category according to Table 2-1 (Sds & Sd1), assuming Site Class D or E. This is hard for me to believe that this is the case, Seismic Design is excluded from the Florida Building Code, and according to a VA Seismicity Map, based on FEMA 310, they have all of Florida as "LOW" Seismicity. I should be getting the same results as the VA Map if I used FEMA 310 and that is what the map is based on, I am assuming?

This area is generally very sandy, with some organics and clayey soils, and then you may have limestone down 100+ feet... We usually get allowable soil bearing capacities in the 2-3ksf range. Using ASCE Table 9.4.1.2 it would seem we would be D or E, though if soil brg capacity is anything like su (avg undrained shear strength in top 100ft) then maybe we could have a Class C.

The VA Map I have does not show what site class they assume, so that has to be the difference, unless it is spectral response that is the issue. I was using ASCE 7 to determine both the Ss and S1 values, as well as the Site Class. FEMA 310 says to use one of their seismic maps, though I have not been able to locate it. It is called Seismic Map Package. I would be surpised if these were not the same or close to ASCE, but this is not may area of expertise.

Anyone have any input? Please CC me directly. Or a link or PDF or FEMA Seismic Map Package.

I am just trying to determine my scope for a proposal, and would like to be in the ballpark with my time required... TIA!

Andrew Kester, P.E.
Principal/Project Manager
ADK Structural Engineering, PLLC
1510 E. Colonial Drive, Suite 301
Orlando, FL 32803

Flat Slab Punching Shear Reinf.

I am analyzing an existing slab for a change in occupancy load. The
drawings are about 40 years old and have a 9" thick flat slab with 15"
square columns. Over the columns they call for shear bars that are
bent longitudinal bars but there are not any stirrups. The "shear
bars" called for look something like this ______/========\______.

I think I have seen bent bars like these in concrete joists to resist
shear in older drawings before. In my case, they are straight at the
bottom, then bend upwards at 45 degrees, are flat along the top over
the column, then bend down at 45 degrees and are straight again along
the bottom of the slab.

Can you use bars like this under ACI today to resist punching shear in
a flat slab? ACI talks about longitudinal bars AND stirrups but the
shear bars they call for on these drawings are just several bent bars
like I described over the columns.

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

RE: Residential Foundation Tipping

Is there any evidence of floor system buckling at the top of the wall level?

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 11:07 AM
To: seaint@seaint.org
Subject: RE: Residential Foundation Tipping

Foundation wall is 9’-3” tall. There is a basement slab on grade on the inside. It is backfilled the height of the wall on the outside, minus the top 6”.

David Maynard

Gillette, WY

From: Rhkratzse@aol.com [mailto:Rhkratzse@aol.com]
Sent: Friday, June 20, 2008 12:04 PM
To: mblangy@satco-inc.com; seaint@seaint.org
Subject: Re: Residential Foundation Tipping

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It’s a residential foundation, 9’-3” wall on top of 8” by 16” continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it’s a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)

RE: Residential Foundation Tipping

There might be something to this. I may have to go back out to the house to see what the spacing of the sill plate anchors were at. If they are too far apart, or just not big enough, we may have some issues.

From: Steve Gordin [mailto:sgordin@sgeconsulting.com]
Sent: Friday, June 20, 2008 12:54 PM
To: Seaint
Subject: Re: Residential Foundation Tipping

Terek,

As bad as it looks, it still may work, provided the slab is present. There is somehting else here, too.

The inward rotation of the wall points more to the floor at its top giving way than to the inadequacy of the foundation.

V. Steve Gordin, SE
Irvine CA

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

From: Tarek Mokhtar

To: seaint@seaint.org

Sent: Friday, June 20, 2008 11:41

Subject: Re: Residential Foundation Tipping

Dave,

I do not think an 8" x 16" "footer" works for a 9' tall retaining wall

Tarek Mokhtar, SE

Laguna Beach

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)
-- 

Re: Residential Foundation Tipping

Terek,

As bad as it looks, it still may work, provided the slab is present. There is somehting else here, too.

The inward rotation of the wall points more to the floor at its top giving way than to the inadequacy of the foundation.

V. Steve Gordin, SE
Irvine CA

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

From: Tarek Mokhtar

To: seaint@seaint.org

Sent: Friday, June 20, 2008 11:41

Subject: Re: Residential Foundation Tipping

Dave,

I do not think an 8" x 16" "footer" works for a 9' tall retaining wall

Tarek Mokhtar, SE

Laguna Beach

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)

--

Re: Residential Foundation Tipping

David Maynard wrote:
>
> Got this call earlier this week. Like to hear what everyone has to say.
>
> It's a residential foundation, 9'-3" wall on top of 8" by 16"
> continuous footer. Reinforcing unknown. The wall is actually tipping
> into the building. Anchor bolts on the outside have broken the
> concrete out at several locations. Soils report says it's a
> sandy-clayey-silt. Took samples from the surface and brought to
> another dirt-engineer who, at sight and touch, believes it to be a
> lean or fat clay. *shrug* Jury is still out on this one. Current
> landscaping is exposed backfill, or NO landscaping at all. There is a
> perimeter sub-drain (one of those perforated pipes surrounded by
> Styrofoam peanuts in a mesh sock) around the base of the foundation.
> House, and wall where damage exists, is about 100 feet away from the
> base of a hill. There appears to be positive drainage away from the house.
>
> I have my own suspicions as to what could have happened, but I am
> curious if anyone has run into this on their end. Anyone? Anyone?
> Foundation damage that I have typically seen is either settlement and
> heave.
>
> Dave Maynard, PE
>
> Gillette, WY
>
It sounds like that the lateral pressure from the exterior backfill has
overloaded the connection at the top of the wall to the floor framing. I
am surprised that the bolts popping out is the weak link.

RE: Residential Foundation Tipping

I am of a mind to agree with you. It seems awfully narrow for a continuous footer. This was the recommendation coming out of the Soils Report!!!

I believe there is a fix, but I wanted to pick the minds of those here before I dive in. I think this problem could be, at least, halted with some helical pier tie-backs. It could be corrected, but it may cause damage elsewhere around the house.

Dave Maynard

Gillette, WY

From: Tarek Mokhtar [mailto:Tarekmokhtar@earthlink.net]
Sent: Friday, June 20, 2008 12:41 PM
To: seaint@seaint.org
Subject: Re: Residential Foundation Tipping

Dave,

I do not think an 8" x 16" "footer" works for a 9' tall retaining wall

Tarek Mokhtar, SE

Laguna Beach

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)

--

Re: Residential Foundation Tipping

Dave,

I do not think an 8" x 16" "footer" works for a 9' tall retaining wall

Tarek Mokhtar, SE

Laguna Beach

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)

--

Re: Residential Foundation Tipping

Dave,

What is going on at the corners of the basement?

How old is the house?

When did that all start?

Where does the drain at the bottom drain to?

Where is the water table?

Is there water in the basement?

Looks like an impeding/ongoing structural failure, so for the moment soil properties may be not that important. Do you think the residents need to get out?

V. Steve Gordin, SE
Irvine CA

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

From: David Maynard

To: seaint@seaint.org

Sent: Friday, June 20, 2008 11:07

Subject: RE: Residential Foundation Tipping

Foundation wall is 9'-3" tall. There is a basement slab on grade on the inside. It is backfilled the height of the wall on the outside, minus the top 6".

David Maynard

Gillette, WY

From: Rhkratzse@aol.com [mailto:Rhkratzse@aol.com]
Sent: Friday, June 20, 2008 12:04 PM
To: mblangy@satco-inc.com; seaint@seaint.org
Subject: Re: Residential Foundation Tipping

I *assumed* it's a basement wall.

Ralph

In a message dated 6/20/08 11:01:53 AM, mblangy@satco-inc.com writes:

I love these kinds of things. I used to work for an veteran engineer who got these calls from colleagues a lot.

So there is no lateral earth pressure on either side of the wall, correct? Is there a SOG present on either side?

Michel

-----Original Message-----
From: David Maynard [mailto:d_maynard@wester-wetstein.com]
Sent: Friday, June 20, 2008 10:38 AM
To: seaint@seaint.org
Subject: Residential Foundation Tipping

Got this call earlier this week. Like to hear what everyone has to say.

It's a residential foundation, 9'-3" wall on top of 8" by 16" continuous footer. Reinforcing unknown. The wall is actually tipping into the building. Anchor bolts on the outside have broken the concrete out at several locations. Soils report says it's a sandy-clayey-silt. Took samples from the surface and brought to another dirt-engineer who, at sight and touch, believes it to be a lean or fat clay. *shrug* Jury is still out on this one. Current landscaping is exposed backfill, or NO landscaping at all. There is a perimeter sub-drain (one of those perforated pipes surrounded by Styrofoam peanuts in a mesh sock) around the base of the foundation. House, and wall where damage exists, is about 100 feet away from the base of a hill. There appears to be positive drainage away from the house.

I have my own suspicions as to what could have happened, but I am curious if anyone has run into this on their end. Anyone? Anyone? Foundation damage that I have typically seen is either settlement and heave.

Dave Maynard, PE
Gillette, WY

**************
Gas prices getting you down? Search AOL Autos for fuel-efficient used cars.
(http://autos.aol.com/used?ncid=aolaut00050000000007)