HomeMy WebLinkAbout09272004 BSC Agenda Item 1 • •
Draft amendment of the
Standard Codes Schedule
regarding foundations
With changes from the "markup"at BSC meeting 8-5-04
(document revised 8-27-04)
Standard Codes Schedule
Adoption. Subject to the amendments and deletions indicated beneath each code, each of the following codes,
including all of its published appendices and attachments, is adopted, ordained and made a part of the Code of
Ordinances of the City and of each chapter where it is referenced, except as otherwise expressly provided.
Procedure for amendments,etc. The procedure for adopting new codes, updated codes, local amendments and
provisions for administration and enforcement of these codes is as follows: (1)proposal by the building official
or other appropriate City official, (2)referral to the Building&Standards Commission, (3)consideration by the
City Council, after giving required meeting notices, and(4)adoption and publication, as required by Article II of
the City Charter.
International Building Code, 2000 Ed.,International Code Council,Inc..
* * *
k s than 450 sq. ft. of gloss floor area),and
further.
3. All foundations for new buildings (or additions to existing buildings)with more than one
story, or with a gross floor area of 485 square feet or more, must meet the criteria in this
section, as applicable. In this section:
"RLPE"means a licensed or registered professional engineer who is:
(1) employed by a registered engineering firm and
(2) covered by professional errors and omissions insurance with limits
of at least$500,000 per year, aggregate; and
"RLGE"means a licensed or registered geotechnical engineer who is:
(1) employed by a registered engineering firm; and
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(2) covered by professional errors and omissions insurance with limits
of at least$500,000 per year, aggregate.
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) that could affect a
foundation,the RLPE must certify that the trees have been taken into account in
the preparation of the plans and specifications.
b. Geotechnical Report. 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.
Partial exception: If 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 below,the testing, evaluation and report
may be limited to a determination of the appropriate depth for the deep
foundations, but they must meet the other applicable criteria.
The minimum depth of borings is 20 feet in all cases. All tests and other
laboratory work must be performed by a laboratory accredited for such work 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").
c. Foundation Performance Standard. The plans and specifications for each
foundation must be prepared to achieve a foundation soil movement potential of
one inch or less, determined by the estimated depth of the active zone in
combination with at least two of the following methods:
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(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.
(Partial exception: If 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 below, neither a PVR determination nor a swell,
suction or hydrometer test is required.)
d. Foundations, Basic Types. Each foundation must be of an approved basic type.
Approved basic types are listed below. In this list,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 City Secretary's office ("FDO").
(1) Structural slab with void space and deep foundations.
(2) Structural floor with crawl space and deep foundations.
(3) Stiffened structural slab with deep foundations.
(4) Stiffened non-structural slab with deep foundations.
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(5) Grade-supported stiffened structural slab.
(6) Grade-supported stiffened non-structural slab.
(7) Grade-supported non-stiffened slab of uniform thickness (approved for
one-story buildings--or additions to buildings--containing only garage or
storage space, not habitable space).
(8) Mixed-depth system for all new building construction.
(9) Mixed-depth system for building additions with deep foundations.
(10) Another type approved by special exception issued by the BSC. See (h),
below.
e. 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.
f. Foundations, 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) Welded wire fabric reinforcing(approved for one-story buildings--or
additions to buildings--containing only garage or storage space,not
habitable space).
(3) Another type approved by special exception issued by the BSC. See (h),
below.
g. Foundations, Observation & Certification. Each foundation must be
professionally observed and must be certified by an RLPE,as more fully
described below:
(1) Observations must:
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(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,
stressing, tendons, tensions, attachments, etc. before the work is
covered or concrete is placed,
(iii) be performed continuously during placement of concrete and any
stressing or tensioning operations, 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) state that the work complies with sound engineering practices,
(iv) comply with criteria as to form and content as may be specified by
the building official,
(v) be signed and sealed by the certifying RLPE, and
(vi) 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) be kept on file by the City, for public inspection, for an indefinite
period of time.
Before framing or other work commences atop a foundation(and before the
foundation is otherwise covered),the permittee must obtain written
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acknowledgment from the building official that the certification for the foundation
was duly filed as required above.
h. 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
(for its estimated useful life); 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.
In connection with any such 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.
4. All concrete piers, footings and foundations must be cured for at least 72 hours before any
significant load is placed on them.
5. All walls and ceilings within a R-1, R-2, R-3 and R-4 type occupancy shall be sheathed
with Type X gypsum board at least 5/8-inch(15.9 mm)thick. Exception: Where this
code(IBC)requires otherwise for moisture protection.
6. Delete: Appendices A (Employee Qualifications), B (Board of Appeals) and D (Fire
Districts).
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