| 9.23.6.1. |
Anchorage of Building Frames
- Except as required by Sentence 9.23.6.3.(1), building frames shall be anchored to the foundation unless a structural analysis of wind and earthquake pressures shows anchorage is not required.
- Except as provided in Sentences (3) to (6), anchorage shall be provided by
- embedding the ends of the first floor joists in concrete, or
- fastening the sill plate to the foundation with not less than 12.7 mm diam anchor bolts spaced not more than 2.4 m o.c.
- For buildings with 2 or more floors supported by frame walls that are in areas where the seismic spectral response acceleration, Sa(0.2), is not greater than 0.70 or the 1-in-50 hourly wind pressure (HWP) is equal to or greater than 0.80 kPa but not greater than 1.20 kPa, anchorage shall be provided by fastening the sill plate to the foundation with not less than two anchor bolts per braced wall panel, where all anchor bolts used are
- not less than 15.9 mm in diameter, located within 0.5 m of the end of the foundation, and spaced not more than 2.4 m o.c, or
- not less than 12.7 mm in diameter, located within 0.5 m of the end of the foundation, and spaced not more than 1.7 m o.c.
- For buildings supported by frame walls that are in areas where the seismic spectral response acceleration, Sa(0.2), is greater than 0.70 but not greater than 1.8 and the 1-in-50 hourly wind pressure (HWP) is not greater than 1.20 kPa, anchorage shall be provided by fastening the sill plate to the foundation with not less than two anchor bolts per braced wall panel located within 0.5 m of the end of the foundation and spaced in accordance with Table 9.23.6.1.
Table 9.23.6.1.
Anchor Bolt Spacing where the 1-in-50 HWP ≤ 1.20 kPa and 0.70 < Sa(0.2) ≤ 1.8
Forming Part of Sentence 9.23.6.1.(4)
Notes to Table 9.23.6.1.:
(1) See Note A-9.23.13.2.(1)(a)(i).
(2) All constructions include support of a roof load in addition to the indicated number of floors.
- Anchor bolts referred to in Sentences (2) to (4) shall be
- fastened to the sill plate with nuts and washers,
- embedded not less than 100 mm in the foundation, and
- so designed that they may be tightened without withdrawing them from the foundation.
- Where the seismic spectral response acceleration, Sa(0.2), is greater than 1.8 or the 1-in-50 hourly wind pressure is equal to or greater than 1.2 kPa, anchorage shall be designed according to Part 4.
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| 9.23.6.2. |
Anchorage of Columns and Posts
- Except as provided in Sentences (2) and (3), exterior columns and posts shall be anchored to resist uplift and lateral movement.
- Except as provided in Sentence (3), where columns or posts support balconies, decks, verandas or other exterior platforms, and the distance from finished ground to the underside of the joists is not more than 600 mm,
- the columns or posts shall be anchored to the foundation to resist uplift and lateral movement, or
- the supported joists or beams shall be directly anchored to the ground to resist uplift.
- Anchorage is not required for platforms described in Sentence (2) that
- are not more than 1 storey in height,
- are not more than 55 m2 in area,
- do not support a roof, and
- are not attached to another structure, unless it can be demonstrated that differential movement will not adversely affect the performance of the structure to which the platform is attached.
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