AWWA COMMENT PERIOD ON AWWA D110, Wire- and Strand-Wound, Circular, Prestressed Concrete Water Tanks

AWWA COMMENT PERIOD ON AWWA D110, Wire- and Strand-Wound, Circular, Prestressed Concrete Water Tanks

AWWA solicits public comments on all proposed new AWWA Standards, and on all proposed revisions, reaffirmations, or withdrawals of existing AWWA Standards. The referenced standards project is being considered for approval and the publication of this notice begins the 45-day public comment period for AWWA and ANSI. An electronic public review copy of the proposed standard can be obtained for review during the comment period by emailing ETS Support (ETSsupport@awwa.org). Comments must be submitted in writing to the AWWA contact listed below no later than the last day of the comment period specified herein. Such comments shall be specific to the section(s) of the standard under review and include sufficient detail, so as to enable the reader to understand the commenter’s position, concerns and suggested alternative language, if appropriate.

AWWA Comment Period closes on November 11, 2024.

Send comments to:
Frank Kurtz, FKurtz@awwa.org
303.347.6221 phone

The review copy will be edited for publication and may also be revised as appropriate based on any comments received during the public comment period. Therefore, this copy is not suitable for continued utilization and is intended only for comment purposes.

Final publication of the standard may take several months. When it is available, a notice will be published in the official notice section of Journal – American Water Works Association. The standard becomes an effective AWWA standard on the first day of the month following such publication in Journal – American Water Works Association.

SCOPE
The intent of this standard is to provide minimum requirements for the design, construction, inspection, and maintenance of wire- and strand-wound, circular, prestressed concrete water tanks with the following four types of core walls:

• Type I—cast-in-place concrete with vertical prestressed reinforcement
• Type II—shotcrete with a steel diaphragm
• Type III—precast concrete with a steel diaphragm
• Type IV—cast-in-place concrete with a steel diaphragm

MAJOR REVISIONS
This edition of the standard has been edited throughout and includes revisions to stated definitions and terms to achieve a higher degree of consistency among the various AWWA standards. The technical revisions to this standard reflect current thinking and construction practices. These include the following:

1. A global change of design criteria, including provisions for earthquake-induced forces, and references to ASCE 7 has been made from the 2005 and 2010 editions (ASCE 7-05 and ASCE 7-10) to the 2016 edition (ASCE 7-16, Minimum Design Loads and Associated Criteria for Buildings and Other Structures).
2. Vertical tendons are typically referred to as vertical prestressed reinforcement throughout the standard.
3. Definitions for the types of wall-base joints and wall-roof joints have been updated in Sec. 1.2 and moved under the definition for standpipe.
4. Criteria for duct material for bonded tendons has been removed (Sec. 2.7.2 of ANSI/AWWA D110-13(R-18)).
5. The equation for minimum recommended dome thickness for buckling, Eq. 3-1, in Sec. 3.6.3.1 has been modified.
6. Provisions for separate inlet and outlet pipes or a combination of arrangements have been added to Sec. 3.11.1.
7. A section on underdrain piping system design (Sec. 3.11.2.4) has been added as a subsection under Sec. 3.11.2, Tank Appurtenances, Other Tank Piping.
8. The minimum size of roof openings for personnel hatches has been changed from 2.5 ft (0.76 mm) to 3.5 ft (1.07 m) (Sec. 3.11.3.1).
9. An option for mixing units to be provided inside tanks to improve water quality has been added (Sec. 3.11.8).
10. Equations Eq 4-33 and Eq 4-34 for maximum vertical compressive and tensile forces at the wall base, Pc and Pt, respectively, have been modified in Sec. 4.4.5.
11. A maximum allowable shotcrete temperature of 95°F (35°C) has been added for shotcrete when deposited during hot weather (Sec. 5.3.1.2).
12. Quality control testing criteria for wet-mix shotcrete has been modified (Sec. 5.3.4.2).
13. Appendix A, Alternative Method of Analysis Based on UBC 1997, has been removed.