Uplift anchorage for perforated shear wall ends with the 2009 code
Uplift anchorage for perforated shear wall ends with the 2009 code
(OP)
With the transition to the 2009 code, the ICC refers the engineer to NDS SDPWS for design of shear walls. I had a question about one section in particular. In the 2006 IBC, 2305.3.8.2.4 refers to a "minimum tension chord uplift force, T". The ICC instructs the engineer to provide anchorage capable of resisting this tension. Because this was a minimum tension, the engineer had to call out hold-downs even if the dead load stablizing moments were sufficient to resist overturning.
However, NDS SDPWS does not make reference to uplift anchorage at perforated shear wall ends. In 4.3.6.4.2, it talks about the bottom plates being anchored for a uniform uplift force, t, which is equal to the unit shear force, vmax. 4.3.6.1.2 shows how to calculate the tension and compression in the chords of perforated shear walls. However, this section does not refer to the tension calculated as a minimum tension. If the dead load stabilizing moments are sufficient to resist overturning, do I not need to call out hold-downs at the ends of perforated shear wall segments? 4.3.6.4.2.1 (Uplift Achorage for Perforated Shear Walls) is given in addition to the requirements of 4.3.6.4.2.
Let me know what you guys think.
However, NDS SDPWS does not make reference to uplift anchorage at perforated shear wall ends. In 4.3.6.4.2, it talks about the bottom plates being anchored for a uniform uplift force, t, which is equal to the unit shear force, vmax. 4.3.6.1.2 shows how to calculate the tension and compression in the chords of perforated shear walls. However, this section does not refer to the tension calculated as a minimum tension. If the dead load stabilizing moments are sufficient to resist overturning, do I not need to call out hold-downs at the ends of perforated shear wall segments? 4.3.6.4.2.1 (Uplift Achorage for Perforated Shear Walls) is given in addition to the requirements of 4.3.6.4.2.
Let me know what you guys think.






RE: Uplift anchorage for perforated shear wall ends with the 2009 code
Garth Dreger PE
AZ Phoenix area
RE: Uplift anchorage for perforated shear wall ends with the 2009 code
RE: Uplift anchorage for perforated shear wall ends with the 2009 code
This minimum uplift force requirement, however, has been removed from the 2009 IBC. Instead, the code requires the uplift force to be determined using Equation 4.3-5 of the 2005 SDPWS and only requires hold-downs when the dead load moment is not sufficient to prevent uplift (SDPWS section 4.3.6.4.2).
Unlike the 2006 IBC, the 2005 SDPWS / 2009 IBC allows the tension force at PSW ends to be reduced due to the effect of gravity loads, as stated in SDPWS section 4.3.6.4.4 (see also section commentary). Example No. 37 of the 2005 Structural Wood Design Solved Example Problems demonstrates the calculation of a reduced PSW hold-downs force due to the wall weight (page 442).
RE: Uplift anchorage for perforated shear wall ends with the 2009 code
RE: Uplift anchorage for perforated shear wall ends with the 2009 code
I thought the whole point of the perforated shear wall methods was to eliminate the need for hold downs at intermediate segments. I thought it was based on only provided hold downs at each end of the perforated shear wall.
??????
RE: Uplift anchorage for perforated shear wall ends with the 2009 code
DaveAtkins
RE: Uplift anchorage for perforated shear wall ends with the 2009 code