STRUCTURAL RESPONSE - BLDG.pdf5 IDE WAY
ENGINEERING
20305 87th Ave. W.
Edmonds, WA 98026
(425) 673-4160
March 31, 2017
Chuck Miller
City of Edmonds Building Division
121 5th Avenue N.
Edmonds, WA 98020
Subject: Permit #BLD2016-1366 Structural Comment Response
Project: Beach Walk Apartments, 303 Edmonds Street, Edmonds, WA
Chuck,
MiYa 1 7 w`017
Itemized below are responses to the structural review comments provided in your review dated February 9, 2017.
Calculations, where required, have been attached for reference.
21c. The 6.75"x18" glulam beams as specified in plan meet the requirements for a 1 hour fire rating using the
provisions for exposed wood members within Chapter 16 of the NDS. If it is assumed 3 sides char to a depth of
1.8" (Table 16.2.1) the reduced moment of inertia is 1116 in resulting in a fire bending stress of 3534psi. The
capacity is 6383psi using the 2.85 design stress to member strength factor in Table 16.2.2. This is a
conservative analysis approach because only the lower half of the beam is exposed, not the full height of each
side of the beam. A note has been added to the plans requiring an additional tension lamination as required in
Section 16.2.4.
30. The wall lengths utilized in the shear wall calculations were based on the most accurate information available,
CAD generated floor plans. We acknowledge that there will be some minor discrepancies with actual framed
wall lengths, however the net result will have a negligible effect on the on the overall design which
conservatively utilized both rigid and flexible diaphragm assumptions for the shear wall design. The
redundancy in this building does warrant dimensioning every shear wall. If conventionally framed per the plan
set, the structure will perform as intended.
31. The continuous footing as shown on S2.1 is sufficient for the combined point load resulting from the window
and door headers on Grid 7 at G.6. The load combination DL + 0.75(LL +SL) governs with a resulting axial
load of 7.7kips, which is less than the 8.Okip capacity of direct soil bearing shown on page 1.14 in the
calculations. The stem and footing reinforcing would engage additional footing length making the actual point
load capacity of the continuous foundation system much greater than shown.
32. The overexcavation detail within the geotechnical report has been duplicated as Detail 10 on S3.1 and is now
referenced by the foundation plan notes on S2.1.
33a. The intent is for the holdown to be installed with anchorage into the stem wall (6/S3.1). If the holdown length
of the shear wall is reduced by 14", the length of the building jog + 6", the HDU4 holdown remains adequate as
designed. In other words, there is flexibility on its location and it can be installed to a double stud at either of
the wall corners in the building jog constructed per 6/S4.1.
33b. Holdowns have been added to the shear walls marked 23 and 25.
34a. The joist framing has been updated to match the architectural drawings.
34b. The mark 2 holdowns (MST48 straps) as shown in plan are considered adequate at 101% capacity. The shear
wall calculation spread sheet automatically went up to the next size strap at 100% capacity, however the
calculated net uplift of 3689lbs is well within an acceptable margin of error of the 36401b MST48 capacity.
34c. The intent is for the strap to align with the studs, blocking, and HDU4 below. Refer to our Comment 33a
response. Similarly, reducing the holdown length by 14" at this level does not affect the size of the strap as
called out in plan.
Beach Walk Apartments Correction Notice
Sidesway Project No. 16057.01
20305 87th Ave. W.
IDE WAY Edmond5
s, WA 98026
ENGTHEEnrnU (425) 673-4160
34d. Holdowns have been added to the shear walls marked 23 and 25.
35. Shear wall mark 10 has MST37 holdowns at each end in the roof framing plan as shown in the calculations on
pages 2.17 and 2.18. The net uplift on shear wall mark 11 was calculated to be 521lbs which we determined to
be negligible and omitted the MST37 strap in plan.
36. Plan note 7 on S2.2 & S2.3 has been updated and added to S2.4.
37. Based on the manufacturer's literature, the pre-bent strap has a capacity of 3440lbs as detailed with (20) 10d
nails. This capacity is within 7% of the calculated net uplift of 3676lbs, which is a negligible difference.
Please feel free to contact me if there are any additional questions or concerns.
Sincerely,
Chris Bernards, PE, SE, LEED AP
Principal
Beach Walk Apartments Correction Notice
Sidesway Project No. 16057.01
03/31/17