HomeMy WebLinkAbout05052005 BSC Agenda Item 2 • •
MICHAEL M. TALIANCHICH P.E. (Inc)
FINE HOME BUILDERS AND STRUCTURAL ENGINEERS
3819 Arnold St 713 6608799
Houston, Texas 77005
Mr Bryant Slimp
Chairman of the BSC 4/30/05
Dear Bryant
Re: Questions raised at Council meeting on 4/25/05
For the sake of brevity,the document "Foundation Design Options for Residential and
Other Low-Rise Buildings on Expansive Soils" produced by the "The foundation
performance association" will be referred to as "docl".
1. No definition of"Deep Foundations" in proposed ordinance and minimally
described in docl as lying between 8 and 20 feet below the surface.
A foundation is a structure which transfers load from the superstructure to the ground or
soil and typically consists of a floor/beam/pier combination whereby the floor/beam
system is supported by "Piers" in the City of West University. My preference for true
correct representation would be to change the words "Deep Foundations" to "Deep Piers"
as parts of the foundation are not deep, only the piers are deep. -- just a thought.
2. I mentioned that house loads are light and that having too many piers with large
bell bottoms is not a great idea in highly expansive soils, however these design concepts
would be extremely difficult to include in an ordinance and as such, should not be
attempted. I also mentioned that about 95% of foundations failures occur due to heave
and not settlement.
3. I mentioned that the demolition process in extracting the old piers was probably
more of a problem than trees, as large voids created by digging out piers would allow
pockets of water to be present all over the site and under the new house unless precise
compaction methods were used by the demolition contractor to fill in the voids. From my
experience, compaction methods are totally imprecise. Having deep piers tends to
alleviate this problem, however I am referring to deep piers in excess of 15 feet not as
docl suggests that 8 feet could be considered deep.
4. No mention for the structural engineer to be present at the site during the
sampling of the soils required for the preparation of the soils report. I personally gain a
feel for the soils and possible impending problems by being present.
5. No mention of skin friction piers rather than end bearing piers in doe 1.
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6. No mention in doc1 that when using "structural floor with crawl space and deep
foundations",that it is undesirable to have isolated piers in the internal areas of the
foundation unless connected by a stiff grade beam. Most crawl space designs that I have
seen use exactly this method.
7. No mention in docl on a secondary system of incorporated failure remediation if
and when any of the proposed methods fail for whatever reason. It would be very
arrogant of myself or any other engineer to guarantee that our primary design of the
foundation will never fail as it is difficult to predict the behavior of expansive soils over
the short and long term, so therefore it would be prudent to incorporate a backup remedial
system in the primary design. If a backup system was not included,then a description by
the engineer on how the foundation could be rectified in case of a failure at a future time
would be beneficial for the property owner plus it may encourage the engineer to include
this thought process in the design stage and a better foundation may result. It is
interesting to note the following. The new brick house which had a foundation problem,
on the corner of Darcus and Auden in Southside Place used a structural floor with crawl
space, however it is apparent to me that a remedial failure mechanism was not
incorporated into the design as a bulldozer was used to rectify the problem and a new
house is currently under construction. So I must ask the question ---- how would this
new proposed ordinance eliminate the solution used in the above mentioned problem.
Obviously, it would have no effect.
Yours Sincerely
Michael M. Talianchich
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To: City Council Members
From: Bryant Slimp, BSC Chair
Subject: Responses to Issues and Concerns on the Second Reading of the
Foundation Ordinance
Date: April 29, 2005
The BSC chairman and staff have reviewed all of the comments and issues raised by
council members and by Michael Talianchich at the Council meeting on April 25, 2005.
The foundation ordinance presented to City Council as ordinance 1791 addresses all of
these issues and comments. To be more specific:
• Insurance
o Mr. Talianchich commented that general liability (GL) insurance was all the
insurance that was needed, and that a $1,000,000 policy would cost him about
$3,700 per year.
o GL insurance is intended for damage (caused by construction activities) to
tangible property or persons, and errors and omissions (E&O) insurance is for
financial damage to a third party (caused by faulty design).
o Earlier in the year Mr. Talianchich stated that he could not obtain professional
E&O insurance because he acts as general contractor and builds the homes he
designs.
• The BSC added specific language to the ordinance early in 2005 that would
allow the BSC, upon request, to grant exception to the E&O insurance
requirements providing the RPLE chose a design acceptable to the BSC.
• Mr. Talianchich was very pleased with this change and praised the ordinance
as being a very good ordinance.
o E&O insurance is the professional liability insurance that professionals (such as
architects, lawyers, engineers, information technology professionals and
accountants) obtain to cover their work.
• E&O insurance is intended for those who produce professional advise.
• • E&O insurance can be considered as similar to the malpractice insurance
that medical doctors and dentists carry.
o The limits of the E&O insurance required under this ordinance are close to the
minimum levels of E&O insurance offered by the insurance carriers. These
levels are $500,000 per claim and $1,000,000 for total claims.
• These claim levels were reported to the BSC at a workshop session by a
representative of a large E&O insurance carrier. He did not consider these
levels excessive.
• The most recent survey of AIA professionals indicates that about 70% of the
320 respondents (who are in the firms sized between 1 — 5 professionals)
carry E&O insurance for $1,000,000 per claim and $1,000,000 for total
claims.
• A recent survey of structural engineers practicing in the Houston area
indicates that these levels of E&O insurance are fairly common for those
designing foundations.
• The cost varies with the number of jobs sealed and the number of claims on
record for the previous 5 years.
• The cost of E&O insurance for a low volume (5 designs per year) RLPE with
one claim over the past 5 years is about $6,000.
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o The BSC feels that this E&O insurance is the proper insurance to carry and that
the limits in the ordinance are reasonable and not excessive for RLPEs who are
designing foundations for houses in West University.
o The BSC also reiterates that insurance is the last line of defense for the design of
a foundation, not the first line of defense.
o In this ordinance, the responsibility and certification of the design and
construction of a foundation rests with the RLPE who designs the foundation.
• Definition of a "deep" foundation
o Mr. Talianchich stated that there was no definition of a deep foundation and that
there was only a vague reference to the depth of the active zone as being 8 to 20
feet in depth in the FPA document referenced in Note 1 of Section B of the
ordinance.
o The BSC chairman and staff reviewed the FPA document cited in Note 1. The
document defines the deep foundation depth requirement accurately in Section
4.1 titled "Deep Support Systems" which is found on page 8, and again in Section
5.1 titled "Deep Support Components" which is found on pages 21 - 22.
o The depth of the foundation piers for a deep foundation is stated to be below the
depth of the active zone.
o The active zone depth is determined by the required soils analysis, which is
covered under Note 2 of Section B of the ordinance.
o The BSC chairman and staff finds no need to change this ordinance.
• Use of straight shaft foundation piers
o Mr. Talianchich stated that he uses a straight shaft pier on his foundations and
not an under reamed or bell bottomed pier.
o He stated that this is not allowed in the ordinance.
o The ordinance specifically allows straight shaft piers in Section C, part 2.
o The need for further modification to this ordinance is deemed unnecessary.
• Removal of old foundation parts
o Mr. Talianchich stated that the ordinance does not address the disposition of
• foundation parts from demolition work on the site of new house construction. He
stated that the removal of existing foundation parts leaves un-compacted soil,
that disturbed soil is a cause for concern with new construction.
o The ordinance requires the RLPE to assess the construction site before design
work is done to determine the site condition. The site condition includes the
existence and locations of old foundation parts, disturbed soil, as well as the
location of trees and other conditions, which could affect a new foundation.
o Section A of the ordinance requires the RLPE to prepare the plans and
specifications specifically for the site of the work.
o The need for further modification to this ordinance is deemed unnecessary.
• Foundation repair work
o Mr. Talianchich stated that the ordinance does not address repair work on
existing foundations.
o The ordinance is written for new construction and is not intended to address
repair or maintenance work.
o The BSC concluded that repair work would be minimized or moot for foundations
built under this ordinance as written.
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o The BSC concluded that this ordinance, as written, provides the best level of
protection for the city and will help minimize future foundation failures thus
minimizing the need for foundation repairs.
• Judgment calls by City employees and BSC members
o Mr. Talianchich was concerned with the fact that the City of West University did
not have a RLPE on staff.
o The BSC understands there is not an RLPE on staff and the BSC further believes
one is not necessary, providing the design RPLE follows the criteria set out in
this ordinance.
o Mr. Talianchich was concerned that his foundation designs were subject to
review by the BSC, who are citizens and not qualified to judge the work of a
RLPE.
o The BSC does not now nor will in the future review a RLPE's work under this
ordinance. The only time the BSC will get involved with a RPLE is if the RPLE
requests a special exception as to the accepted foundation designs or for relief
from the E&O insurance.
• Engineers are dominated by the builders
o Mr. Talianchich stated, "They [the foundation design engineers] are dominated by
the builders. The builder says 'I want this and if you don't, I'll go to another
engineer.' "
o The BSC chairman and the City's Building Official highly agree with this
statement.
o One of the main purposes of this ordinance was to remove the economic
pressures from the design of a foundation and rely on sound engineering
principals.
o The BSC concluded that this ordinance will require the RLPE to actually design a
foundation to the site using excepted engineering principals that provide the least
risk of failure for the expansive soils in West University.
• Use of certain foundation types in West University
o Mr. Talianchich stated "nobody will use it [a structural slab with void space and
deep foundations and/or a structural floor with crawl space and deep
foundations]."
o Mr. Talianchich stated, "I would like to throw four methods [four of the allowed
basic foundation types in section b] out."
• This ordinance allows for seven foundation types in West University.
• The two types Mr. Talianchich stated are the least risky types of foundations
are types 1 & 2 in the ordinance. Although this ordinance does not require all
foundations to be types 1 or 2, the ordinance highly encourages their use.
• The structural slab with void space and deep foundations has become more
common in the last year after word spread that the BSC was contemplating
recommending that council adopt an ordinance requiring them.
• The structural slab with deep foundation and crawl space is being used more
in areas where flooding is probable.
• Foundation Problems
o Mr. Talianchich stated, "95% of the problems {with failed foundations] occur due
to heave, not due to settlement."
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• The BSC chairman and staff absolutely agree with Mr. Talianchich on this
statement.
• The BSC has written this ordinance with a minimum design criteria of one
inch of potential vertical rise (or heave) on certain foundation types where the
soil is in contact with the slab.
• The BSC felt that both the risk of heave, and the amount of heave, have not
been addressed by foundation design engineers in West University.
• Likewise, foundation types where the slab is not in contact with the soil have
less risk of problems due to heave, and as such, the BSC has reduced the
scope of geotechnical testing and certifications by the RLPE when these
foundation types are used.
o Mr. Talianchich stated that foundations with bell-bottom piers can heave under
certain conditions and that the heave of the soil on the bottom of an under
reamed pier (bell bottom pier) can easily happen.
o The BSC chairman and staff agree with Mr. Talianchich and as such has stated
that the pier must extend through the active zone (where the soils can cause a
foundation to heave) and must extend to a proper point in the inactive zone.
These can be found in the documents referenced Section B.
o The BSC has included the need for a geotechnical soils report as part of the
design to determine the location of the active zone on the specific site so that the
RLPE can design the deep foundation elements to extend beyond the active
zone.
In summary, the BSC chairman and staff feel that all of the issues raised by Mr.
Talianchich and others have been covered in this ordinance, and the BSC chairman
asks the City Council to pass this ordinance on its second reading.
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Amendments to the
Standard Codes Schedule
regarding foundations
Delete the existing paragraph 3 under "International Building Code"and insert
the following:
3. The foundation for each new building (and each new addition to a building)must meet
the criteria in this section, as applicable. In this section:
"A2LA Lab"means a laboratory accredited by the American Association for
Laboratory Accreditation on the basis of ISO/IEC 17025:1999 ("general
requirements for the competence of testing and calibration laboratories").
"RLPE" means a licensed or registered professional engineer of the State of Texas
who is:
(1) listed with the State Board of Professional Engineers in either the
civil or structural branch of engineering (but, from and after May 1,
2006, listing in the structural branch is required);
(2) employed by a registered engineering firm of the State of Texas;
and
(3) (unless waived by the BSC as provided in"f' below) covered by
professional errors and omissions insurance that: (i) has limits of
at least$250,000 per claim (and at least$500,000 per year,
aggregate) and (ii)has effective dates—including any retroactive
coverage date—that include the entire period when the person
provides services or takes actions regulated by this section.
"RLGE"means a person who is:
(1) either: (a) a registered professional geoscientist of the State of
Texas, or(b) a licensed or registered professional engineer who is
listed with the State Board of Professional Engineers in a relevant
branch of engineering (civil, structural or geological) and
employed by a registered engineering firm of the State of Texas;
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and
(2) covered by professional errors and omissions insurance that: (i)
has limits of at least $250,000 per claim (and at least$500,000 per
year, aggregate) and (ii)has effective dates—including any
retroactive coverage date—that include the entire period when the
person provides services or takes actions regulated by this section.
a. Engineering. Foundations must be constructed in accordance with complete plans
and specifications prepared, signed and sealed by a RLPE. The plans and
specifications must be prepared specifically for the site of the work, and they must
meet criteria as to scope, content and form specified by the building official. If
there are existing trees (either to remain or to be removed) within 20 feet of a
foundation, the RLPE must acknowledge, in writing,that the trees have been
taken into account in the preparation of the plans and specifications.
b. Basic Standards. Each foundation must be an approved basic type listed in the
following chart. In addition, the design of each foundation must be supported by a
geotechnical report and special engineering certification, to the extent indicated in
the following chart.
Approved Basic Types. See Note 1. Geotechnical Report. Special Engineering
See Notes 2 and 3. Certification. See Note 4.
Structural slab with void space and deep foundations Limited Not required
Structural floor with crawl space and deep foundations Limited Not required
Stiffened structural slab with deep foundations Full Required
Stiffened non-structural slab with deep foundations Full Required
Mixed-depth system for all new building construction Full Required
Mixed-depth system for building additions with deep foundations Full Required
Another type approved by special exception issued by the BSC. As specified in the As specified in the special
See "f"below. special exception exception
Note 1. Approved Basic Types. Types of foundations are defined and described in"Foundation Design Options For Residential and Other
Low-Rise Buildings on Expansive Soils" published by the Structural Committee of the Foundation Performance Association,
Houston,Texas(Document#FPA-SC-01-0,Rev#0,30 Jun 04,marked"For Website Publishing"),a copy of which is on file in the
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City Secretary's office("FDO").
Note 2. Geotechnical Report,Standards. The plans and specifications for each foundation must be based on a written geotechnical report
prepared,signed and sealed by a RLGE. The report must cover all testing and site evaluation,and all must meet all applicable criteria
in"Recommended Practice for Geotechnical Explorations and Reports" published by the Structural Committee of the Foundation
Performance Association,Houston,Texas(Document#FPA-SC-04-0,Rev#0,11 April 2001,issued for website publishing),a copy
of which is on file in the City Secretary's office. The minimum depth of borings is 20 feet in all cases. All tests and other laboratory
work must be performed by an A2LA Lab.
Note 3. Geotechnical Report, Scope. "Limited" indicates that the geotechnical testing, evaluation and report may be limited to a
determination of the appropriate depth for the deep foundations(but the deep foundation components must meet the other criteria
applicable to them). "Full"indicates that the geotechnical testing,evaluation and report must cover all foundation components.
Note 4. Special Engineering Certification. Where indicated as"required,"for a particular type of foundation,the RLPE must certify that the
plans and specifications were prepared to achieve a soil-caused foundation movement potential of one inch or less,and that the RLPE
used the estimated depth of the active zone and at least two of the following methods to prepare the plans and specifications:
(1)Potential vertical rise (PVR) determined in accordance with Test Method Tex-124-E, Rev. January 1, 1978/December 1982,
Texas State Department of Highways and Public Transportation,Materials and Test Division,"Method for Determining the Potential
Vertical Rise,PVR"(a copy of which is on file in the office of the City Secretary).For this purpose,the"dry"moisture condition
(from which little shrinkage is experienced,but where volumetric swell potential is greatest)shall be used for each sample and test.
(2)Swell tests performed in accordance with ASTM D4546-03,"Standard Test Methods for One-Dimensional Swell or Settlement
Potential of Cohesive Soils"as last revised prior to June 1,2004.
(3)Suction and hydrometer swell tests performed in accordance with ASTM D5298-03"Standard Test Method for Measurement of
• Soil Potential (Suction) Using Filter Paper" and ASTM D6836=02 "Standard Test Methods for Determination of the Soil Water
Characteristic Curve for Desorption Using a Hanging Column,Pressure Extractor,Chilled Mirror Hygrometer,and/or Centrifuge,"as
such methods were last revised prior to June 1,2004.
C. Foundations, Deep Support Components. Deep support components must be of
an approved type. Approved types are listed below. In this list, types of deep
support components are defined and described in FDO.
(1) Drilled and underreamed concrete piers.
(2) Drilled straight-shaft concrete piers.
(3) Auger-cast concrete piles.
(4) Another type approved by special exception issued by the BSC. See "h,"
below.
d. Reinforcement. Reinforcement for each foundation must be of an approved type.
Approved types are listed below. In this list,types of reinforcement are defined
and described in FDO.
(1) Deformed bar reinforcing.
(2) Another type approved by special exception issued by the BSC. See "h,"
below.
e. Observation & Certification. Each foundation must be professionally observed
and must be certified by an RLPE, as more fully described below:
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(1) Observations must:
(i) be performed either by the certifying RLPE or by one or more
persons under that RLPE's direct supervision and control whose
professional qualifications are approved by the RLPE (any such
person may be an RLGE, with respect to geophysical matters),
(ii) include actual measurement of piers, fill, compaction,
reinforcement, forms, materials, dimensions, structural elements,
attachments, etc. before the work is covered or concrete is placed
(Note: dimensions of an underground element may be measured or
estimated from the forms, boring or cavity for the element, before
pouring or filling),
(iii) be performed continuously during placement of concrete, and
(iv) be documented in a form and manner approved by the building
official (which may include photographs).
(2) Certifications must:
(i) refer to and be based upon the professional observations required
by this section,
(ii) state that the work complies with the plans and specifications last
approved by the building official (with any field changes that are
ordered by the RLPE and reported to the building official and that
comply with applicable regulations),
(iii) comply with criteria as to form and content as may be specified by
the building official,
(iv) be signed and sealed by the certifying RLPE, and
(v) be filed with the building official.
(3) Certifications may:
(i) rely in part upon an attached certification by a RLGE, as to
geophysical matters, and
(ii) rely in part upon an attached certification by an A2LA Lab, as to
materials testing.
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Before framing or other work commences atop a foundation (and before the
foundation is otherwise covered),the permittee must obtain written
acknowledgment from the building official that the certification for the foundation
was duly filed as required above. Certifications,plans, specifications and related
items may be kept on file by the City, for public inspection, for an indefinite
period of time.
£ Special Exceptions. The BSC may issue a special exception from any requirement
in subsection"a"through"g," above, but only upon a showing that:
(1) the requirement will not affect life safety or the performance of a structure;
or
(2) an alternate requirement to be imposed by the special exception will
provide equal or better protection for life safety and long-term structural
performance.
However: (i) unless the basic type of foundation is "structural slab with void space
and deep foundations"or"structural floor with crawl space and deep
foundations," as described in this section, the BSC may not issue a special
exception waiving any requirement for an RLPE to have professional errors and
omissions insurance, in whole or in part; and (ii)the BSC may not waive any
requirement for an RLGE to have such insurance. In connection with any special
exception, the BSC may require that the applicant provide supporting engineering
data and opinion, and the BSC may impose conditions to carry out the purpose
and intent of applicable regulations.
Amend paragraph 4 under "International Building Code"as follows:
4. All concrete piers, footings and foundations must be cured for at least 72 hours before any
significant load is placed on them.
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