Reviewed by: Bolen, Wayne A. Permit #: C12-1227
Phone: 343-8072 Date: 8/30/2012
Fax: 249-7393
Email: BolenWA@muni.org
Permit Manager: Jinny Day
Phone: 343-8338
Email: DayJR@muni.org
Project: UAA Sports Arena
Review Number: 299505
____________________________________________________________________________________
PERMIT STATUS (no response required) 5/16/2012: Review completed. Comments issued.
6/17/2012 – Responses reviewed. Comments issued.
8/30/2012 – Responses reviewed. Comments issued.
10/23/2012 - Met with Engineers to go over what still needs to be done
Advisory Comment (no response required): This review is based on the requirements of the Anchorage Administrative Code (AAC), 2009 International Building Code (IBC), 2009 International Residential Code (IRC) and all adopted references thereto as amended by MOA. The following comments must be addressed before a permit can be issued. The approval of plans and specifications does not permit the violation of the codes, or any federal, state or local regulations.
1. DESIGN OF FOOTINGS FOR UPLIFT
Reference pages 558 through 561 of the calculations. Please provide the following:
A) Please clarify how the uplift forces were determined. Please note that when proportioning footings the vertical seismic load effect can be taken as zero. Please note that the confusion is because based on the earthquake load some of the uplift forces make it appear the dead load component is extremely large. This may be true based on some of the long spans in the roof, but there was not sufficient information provided to verify. Please clarify. See also item C.
Item remains. See item 1C. WAB – 6/17/2012
Item resolved. WAB – 6/20/2012
B) Please provide the design of the footings for the uplift condition. This design must include proportioning the size of the footing, and the design of the reinforcement in the footing to resist the uplift forces. The schedule appears to have options for top reinforcing, but it does not appear as if any footings have been indicated as having top reinforcing. The top reinforcing indicated is less than the bottom reinforcing so the design of this reinforcing must be verified.
Item remains. The proportioning of the footings uses the soil weight including the wedges adjacent to the footings. This method is not permitted to be used. The correct method would be to use Bowles Method with a factor of safety of 2 (we have accepted an FS of 1.67 as well). Please talk to Scott Gruhn about the Bowles Method as he is familiar with this method.
Please verify the following footings do not need top reinforcement – F22.0 on grid 9 between grids B.7 and B.9, F12.0 on grid H/9, M.1/9 (this footing is also missing its size), F6.0 on grid D/9, F14.0 on grid L.5/4, and F5.0 on grid M/4. It is possible that these footings do not have net uplift, but based on the ETABS output they appear to.
Please also clarify the design of the reinforcement for the uplift condition. Please remember that when designing for strength the strength load combinations must be used. For example for the footing on G.6/11.3 the earthquake load is 498 kips per 560 of the original calculations and the dead load appears to be 75 kips. The uplift force would be 0.9*75-498 = 430.5 kips. The load at the footing would be 4.305 plf/ft (430.5 kips/100 sq. ft). The moment from this would be 4.305*5*5/2 (for the 10X10X1.75 footing at this grid) or 53.81 k-ft/ft. The strength of the footing appears to be about 0.31*60*(19-0.456/2)*0.9/12 = 26.187 k-ft/ft based on a cover of 2” and #5 bars at 12” O.C. This is about half the strength that is required. WAB – 6/17/2012
C) Please provide an output file with the reactions for each load case (dead load, live load, snow load, earthquake, etc). It will likely be required to submit graphical representation of where each joint is located so the footing designs can be verified.
Item remains. The best way to resolve this comment is to take a couple of the footings and show how each load was determined (i.e. show where the dead load was taken from…same with live, snow, and earthquake). From here it is easy for the reviewer to verify the reactions used. WAB – 6/4/2012
Item resolved.
Please note that additional comments may be generated on the response to these comments.
2. OTHER F&F DESIGN COMMENTS
Reference the calculations. Please provide the following:
A) Reference page 351 of the calculations. There is a section called bearing where the shear plates are designed that the spreadsheet indicates to verify. Please clarify.
Item resolved. Response accepted. WAB – 6/17/2012
B) Reference page 707 of the calculations. ASCE 7-05 section 12.2.7.2 limits the axial load in cantilever columns to 15% of the axial capacity of the column. It appears the columns on grid A exceed this limitation. Please clarify. Please note that this also applies to the grid N columns designed on page 728.
Item resolved. f’c for these columns has been changed to 5,000 psi. WAB – 6/17/2012
C) Reference page 706 of the calculations. It appears that the cantilever column system chosen is the Special Reinforced Concrete Moment Frame option. This would require the columns to meet all the requirements for Special Reinforced Concrete Moment Frames except for ACI 318-08 sections 21.6.2 and 21.7 (since there are no column to beam moment connections and no concrete beams). All other sections from ACI 318-08 section 21.5 through 21.6 must be met. Please verify that these requirements have been met. Reference ASCE 7-05 table 12.2-1.
D) Reference page 713 of the calculations. This design appears to be for the columns on grid A for lateral loads perpendicular to the wall. Please clarify how the earthquake load was determined. 59/2.4 = 24.583 kips, and this doesn’t appear to be one of the loads shown on page 706 of the calculations.
E) The building height on grid N is 60’+, and even if a two stage analysis is done, it is almost 40’. This exceeds the height limitations for a Special Reinforced Concrete Moment Frame Cantilever Column System. For this system the height is limited to 35’. Please clarify.
Item resolved. Please note that the original drawings still have the braced frames above the cantilever columns which pushed the height to over 35 feet. The new drawings do not have these braces, and this part of the framing is gone. WAB – 6/17/2012
F) Reference the calculations. It doesn’t appear as if the connection of the trusses to the concrete columns on grids A and N have been provided. Please provide or indicate where in the calculations this design has been done.
Item remains. It appears the design of the anchors has been done assume that shear breakout is confined. Please clarify how this is done. If the ties are being used they must be placed such that they can be developed on either side of the potential shear breakout planes. As they are current placed it doesn’t appear as if this is the case.
G) Reference the calculations. It doesn’t appear as if the design of the column anchors has been provided. Please provide these designs or indicate where in the calculations these designs have been done. Reference IBC section 1912. The anchors are the braced bays are the ones of the most concern. Reference AISC 341-05 section 8.5.
Item remains. The referenced pages of the calculations only appear to provide design for the anchors for concrete breakout (by precluding this limit state). It doesn’t appear as if a shear design or design for pullout has been provided. Please clarify. WAB – 6/17/2012
H) Reference detail 3 on sheet S521. Please provide design of the anchorage for this braced frame base. Reference IBC section 1912.
Item no longer applicable. It appears this detail has been deleted. WAB – 6/17/2012
I) It is not clear from the calculations or the drawings how lateral shear loads are transferred at the foundation level. There does appear to be footing ties on grids 4 and 9, but otherwise it is not clear. Please clarify.
Item remains. Please provide a note on the drawings indicating the slab on grade as a structural diaphragm, and prohibit saw cutting of the slab on grade. Please provide a detail showing how lateral loads are transferred across construction joints.
Where ties are not provided interconnecting footings, the footing gravity loads for columns adjacent to the resisting line columns can not be used to resist lateral forces. Please remove these forces where applied and resubmit.
Please clarify where the diaphragm design loads have been calculated. It appears that the capacities have been determined, but the reviewer was unable to locate the design loads (moments and shears). WAB – 6/18/2012
J) Reference detail 19 on sheet S521. The design of this strut connection could not be located. Please provide design or indicate where in the calculations the design was done.
K) Reference detail 1 on sheet S401. Please clarify how the top of wall is braced or provide design of the wall to cantilever from the ground or span between pilasters or indicate where in the calculations this design was done. Reference ASCE 7-05 section 12.11.1.
L) Reference page 343 of the calculations. The design of this column appears to make the assumption that the diaphragms provide rigid supports. This is not the case. Each diaphragm has its own spring constant which will permit some deflection of the column. It is also not clear why this column has been designed as a W27X368 when it is in fact a built up box section. Please verify the design of this column. Please also note that in the load case including seismic, the diaphragms will in fact being loading the column, and they could be acting is opposite directions. The column must be verified for this as well. Reference ASCE 7-05 section 12.12.2. Please also note that at the balcony level no lateral support is provided by the diaphragm. This level actually loads the column laterally with a couple.
Item remains. Please determine the stiffness of the diaphragm using the 3rd edition SDI and compare to the stiffness of the column. There are issues such as fastener stiffness in the SDI that were not considered. The diaphragm would need to be significantly stiffer than the column as well. WAB – 6/18/2012
M) Reference page 323 and 343 of the calculations. Please verify AISC 360-05 section E4 does not apply to the built up box sections or provide design check per this section. The section seems to imply that it only applies to open sections, but this isn’t clear.
Item no longer applicable. These sections have been replaced with regular sections. WAB – 6/17/2012
N) Reference detail 1 on sheet S517. Is this supposed to be the fixed W12 to concrete column connection? Please provide design of this connection or indicate where in the calculations the design was done. The bottom flange of the beam has been cropped which substantially impairs the capacity of the beam in bending as this would be the compression side in this case.
Item resolved. Please note that this comment was made before a full review was done. WAB – 6/17/2012
Please note that additional comments may be generated from the response to these comments.
3. FOOTING AND FOUNDATION DRAWINGS
Reference the drawings. Please provide the following:
A) Reference sheet S202. There is a detail cut near grids J and 8 that appears to be missing the reference. Please provide. This same cut shows up on sheet S204 without the reference.
Item resolved. Response accepted. WAB – 6/4/2012
B) Reference sheet S204. The footings around the interior lower slab have a top of footing elevation of -16’-8”. This puts the top of footing at the elevation of the upper slab, and above the elevation of the lower slab. Is this the intent? Please clarify.
C) Reference sheet S204. Please provide a detail cut at the change in slab elevation.
D) Reference sheet S204. There appears to be a foundation wall with footings around the lower slab area. Please provide the top of footing elevation for the footings under these walls.
E) Reference sheet S204. There are two footings at the elevator pit that have the same top of footing elevation as the top of slab for the elevator pit. Is this the intent? Please clarify. These footings are also shown on sheet S206.
Item remains. Response accepted; however please provide a detail showing the interaction between the footing and the elevator pit. WAB – 6/4/2012
F) Reference sheet the foundation plans. There are several sheets where it doesn’t appear as if the top of footing elevations have been provided for the strip footings under the foundation walls. Please clarify.
Item resolved. It appears these elevations have been provided. WAB – 6/17/2012
G) Reference sheet S211. There is a detail cut near grids E and 9 that doesn’t appear to have a reference. Please provide.
Item resolved. This has been corrected. WAB – 6/17/2012
H) Reference sheet S211. There is a detail cut on grids D and 12 that references detail 1 on sheet S205. Please verify that this reference applies at this location.
I) Reference sheet S213. Please clarify where the top of slab elevation has been indicated.
J) Reference sheet S213. There are foundation walls above and below grid 6. Please clarify if there are supposed to be footings underneath these walls. Please provide a detail cut in these areas to show the construction of these walls.
Item remains. There are footings shown under the foundation walls above grid 6, but it was not clarified if footings are required under the foundation walls below grid 6. Please clarify. WAB – 6/17/2012
K) Reference the foundation plans and sheet S502. Please clarify where each pilaster type applies. A lot of the footings have pilaster sizes indicated, but many do not.
Item remains. Please provide the pilaster sizes at the following locations: near grid 12 and F on sheet S202, on grid 9 near grid M on sheet S202/S212, on grid F/3 on sheet S205, on grid 0.4 near grid F on sheet 205, on grid 0.4 between grids G and H on sheet S206, near grid 3 between grids L and M on sheet S206, near grid 3 on grid N on sheet S206, on grid 4/B on sheet S213, on grid 4 near grid C on sheet S213, on grid 2 between grids B and C on sheet S215, on grid 3 between grids B and C on sheet S215, on grid C between grids 1 and 2 on sheet S215, on grid 1/D on sheet S215, on sheet S216 on grids H, J, K, and L between grids 1 and 3. WAB – 6/17/2012
L) Reference detail 19 on sheet S502. There is a detail cut that appears to be missing the reference. Please provide.
Item resolved. This cut has been removed. WAB – 6/17/2012
M) Reference detail 4 on sheet S401. This section shows one of the pilasters not extending to bottom of slab. Is this the intent? Please clarify. It appears all other sections shows the pilasters extending to bottom of slab. If the intent is to not have the pilaster extend to top of slab, please provide bottom of column elevations or top of pilaster elevations.
Item resolved. Response accepted. This information can be found in the base plate schedule. WAB – 6/17/2012
N) Reference the frame elevations on sheets S401 through S411 of the drawings. It appears several of the columns frame to top of footing even where top of footing is substantially below slab elevation. Is this the intent? Will these columns have concrete poured around them? Please clarify.
O) Reference detail 2 on sheet S403. There is a detail cut on this section with no reference. Please provide the reference.
P) Reference detail 19 on sheet S521. This detail indicates a W35X118 beam. This should be W33X118. Please revise.
Q) Reference detail 9 on sheet S521. This detail references another detail, but the reference isn’t provided (it shows up as _/S_). Please revise. This detail also indicates (3) #3 ties at 2” O.C. at top of the pier. This may not meet the requirement to have (3) #3 ties in the top 5”. It is recommended that the detail be revised to indicate (3) #3 ties or (2) #4 ties in the top 5”.
R) Reference details 5 and 6 on sheet S521. There is information missing in these details. The information missing is shown as underscores. Please revise.
S) Reference detail 5 on sheet S501. This detail shows how to construct a footing step. It is not clear from the plans where the footing steps occur. Please clarify.
T) Reference details 17 and 19 on sheet S502 of the drawings. Please clarify the lateral load path for the lateral loads from the cantilever columns into the concrete shear walls. While the cantilever column transfers the lateral loads to the wall on one side in direct bearing, it pulls on the wall on the other side, and must have rebar to tie it to the wall. The wall reinforcing can be used provided there is sufficient capacity to make the transfer.
U) Reference detail 1 on sheet S517. Please provide the rebar size for the plate embed. Please note that for shear friction the reinforcement must be developed on both sides of the potential shearing plane. It is not clear that this has been met. Reference ACI 318-08 section 11.6.8.
4) STATEMENT OF SPECIAL INSPECTIONS
Please provide a statement of special inspections in accordance with IBC Chapter 17. The statement of special inspections must include both the type and frequency of the inspections.
Comment resolved. Response accepted. WAB – 6/17/2012
5) SPECIAL INSPECTOR
Please provide a letter from the Owner indicating who they will be hiring to provide the special inspections on this project. The special inspector(s) must be licensed by the MOA in the type of inspection(s) to be performed. Reference IBC section 1703.1.
6) FRAMING PLANS
Reference the drawings. Please note that the structural drawings are substantially incomplete so responses to the items in this comment may generate additional comments. Please also note that the framing plans have virtually no detail cuts and references making the review of the drawings extremely difficult as it is not clear that each condition has been detailed. Please provide detail cuts and references on the plans so that it can be verified that each condition has been sufficiently detailed. Please also note that top of steel elevations have not been provided in most cases. This information must be provided. Please also provide the following:
A) Reference sheet S211. There is a detail cut between grids E and F and near grid 9 that is missing the reference. Please provide the reference. This is the only detail cut provided for the framing on this sheet.
Item resolved. Response accepted. WAB – 6/30/2012
B) Reference sheet S212. On grid 9, the following beams have not been indicated as drag struts: the W14X109 spanning from grid H, and the W33X118 spanning to grid L. Please clarify why these are not drag struts.
Item resolved. The W33 has been indicated as a drag strut now, and the W14X109 is a drag by the referenced detail. WAB – 6/30/2012
C) Reference sheet S213. There are several details cuts with no references. There are three on grid F and near grids 5 and 8 and one between grids E and F near grid 9. Please clarify.
Item resolved. The references have been added or the cut has been removed. WAB – 6/30/2012
D) Reference sheet S214. Several of the beams on grid 4 appear to have fixed end connections. Is this the intent? Please clarify. Please note that this occurs throughout the framing plans, but it is not clear that the intent of the solid triangle end condition is meant to be a fixed connection.
E) Reference sheet S214. There are two detail cuts near grid F that have no reference. They are near grids 5 and 9. Please clarify.
Item resolved. These cuts have been removed. WAB – 6/30/2012
F) Reference sheet S214. Please verify the detailing of the diaphragm at the opening in the center. The chords may be discontinuous at upper and lower corners. Reference ASCE 7-05 section 12.10.
Item resolved. Response accepted. There are concrete walls all around the opening in this diaphragm so the chord is not discontinuous. WAB – 6/30/2012
G) Reference sheet S214. Please verify whether the beams on grid 4 are supposed to be indicated as drag struts. It also appears that some of the beams along grid 9 have not been indicated as drag struts but they appear to be so. Please clarify.
Item resolved. This has been clarified. WAB – 6/30/2012
H) Reference sheet S223. There appears to be framing shown between grids D and E on grid 4, but the framing hasn’t been indicated. Please clarify. The framing between grids C and D appears to have a double call out and it is not clear what this framing size is. Please clarify.
I) Reference sheet S226. There is a beam that spans to grid L between grids 2 and 3 that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
Item resolved. Response accepted. This beam is a drag strut, but the standard beam connection is sufficient to transfer the required loads. WAB – 6/30/2012
J) Reference sheet S226. There is a beam between grids 1 and 2 that spans from F.9 to G.3 that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
K) Reference sheet S226. There is a beam on grid 4 spanning from grids F to G that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
L) Reference sheet S231. There is a beam on grid 9 that spans from grids B to C that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
Item resolved. This beam has been indicated as a drag strut. WAB – 6/30/2012
M) Reference sheet S231. The beams along the “curve” have been indicated with note 8 which requires slip critical connections with faying surfaces classified as Class A or better. This seems to imply that these beams are drag struts/collectors. Is this the case? Please clarify.
Item resolved. This “line” is not a collector line. WAB – 6/30/2012
N) Reference sheet S231. There are two beams near grid F spanning from grids 10 to 12 that appear to be drag struts, but have not been indicated as such. Please clarify.
O) Reference sheet S231. There is a beam on grid 10 that spans between grids B and C that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
P) Reference sheet S232. There is an opening in the diaphragm between grids 11 and 12 and G and H that may need a load transfer detail around the opening on the side closest to grid G. It may be possible to use the rebar at this location. Please clarify.
Item resolved. The response to this comment did not seem to address the comment however there are drag strut beams on either side of this opening that can transfer any chord forces required. WAB – 6/30/2012
Q) Reference sheet S232. There are two beams on/near grid 11 and spanning from E.5 to F.9 that appear to be drag struts, but haven’t been indicated as such. Please clarify.
R) Reference sheet S232. There is an opening in the diaphragm between grid 9 and 10 and grids K and L that may need a load transfer detail around the opening on the side closest to grid L. The slab reinforcement may be sufficient to provide this transfer. Please clarify.
Item resolved. There are drag strut beams around this opening that can act as the force transfer around the opening. WAB – 6/30/2012
S) Reference sheet S233. There appears to be one or two beams on grid 4 that span from grids B to C that appear to be drag struts, but haven’t been indicated as such. Please clarify.
Item remains. Per page 1605 of the original calculations the load at the end of the W24X55 appears to be 189 kips. The standard connection for this beam is (7) ¾” diameter A325N bolts. Each of these bolts are good for 15.9 kips of shear (LRFD) which leads to a capacity of 15.9*7 = 111.3 kips. Please clarify. Please note that the elevations indicates detail 1 on sheet S512 and it is possible that this detail applies to the W24X55, but it may only apply to the W30X132 above which is indicated as a drag strut. It may also be possible that the lateral loads between grids B and C at the balcony level are to be transferred to the W30X132, but if this is the case the W24X55 would still be need to collect the load to the W30. Please clarify. WAB – 6/30/2012
Item resolved. This beam has been changed to a drag strut. WAB – 8/28/2012
T) Reference sheet S233. The HSS struts near grid E appear to be drag struts, but haven’t been indicated as such. Please clarify.
Item remains. The response is accepted; however reference detail 8 on sheet S521 of the drawings. The connection of the HSS struts appears to be indicated as a ¼” flare bevel weld. Flare bevel welds are not indicated with a thickness of weld. The qualified flare bevel weld is to fill the radius area, and to design the weld with a thickness of 5/16*radius or 5/8*radius depending on the process used. Reference AISC 360-05 table J2.2. Please revise the detail.
Item remains. The response indicates that the detail has been revised, but this doesn’t appear to be the case. Please revise and resubmit. WAB – 8/28/2012
U) Reference sheet S233. There is a beam on grid 9 spanning between grids B and C that appears to be a drag strut, but hasn’t been indicated as one. Please clarify.
Item resolved. This beam has been indicated as a drag strut now. WAB – 6/30/2012
V) Reference sheet S234. There is a beam indicated as a W12X30 between grids L and M and 4 and 5 that appears to supports two W21X101 beams. This beam doesn’t appear to have been indicated as the correct size. It appears this should have been a W12X120. Please clarify. It appears this may have been done to the beam between grids G and H and 4 and 5 as well (this beam supports two W21X101s), the beam between grids L and M and 8 and 9 (supports two W21X101), and the beam between grids G and H, and 8 and 9 (also supports two W21X101). Please clarify.
Item resolved. The sizes of these beams have been corrected. WAB – 6/30/2012
W) Reference sheet S234. There are multiple support conditions that do not appear to have been detailed. The beam between grids L and M and 8 and 9 that supports the two W21X101s, the beam between grids G and H and 8 and 9 that supports the two W21X101s, and the beam between grids G and H and 4 and 5 that supports the two W21X101s. Please verify. It appears the general beam to column condition and the beam to concrete wall/column condition have been detailed, but not these. Please note that the details provided may not even be applicable to some of the other conditions as they have a bent beams that frame back to the column.
X) Reference sheet S234. Please verify the diaphragm detailing around the opening in the diaphragm. It’s possible that the slab reinforcement can be used, but this isn’t clear.
Item resolved. There are drag beams around this opening that can act as the force transfer around the opening, and slab reinforcing. WAB – 6/30/2012
Y) Reference sheet S235. The line beams on “this curve” have note 8 indicated which requires a slip critical connections with surfaces prepared as Class A slip critical or better. This would imply that the beams on “this curve” are drag struts, but they have not been indicated as such. Please clarify.
Item resolved. As with the previous “curve” the beams on this line are not collectors. WAB – 6/30/2012
Z) Reference sheet S235. There are three beams on grid 3 spanning from grids B to near E that appear to be drag struts, but they have not been indicated as such. Please clarify.
Item resolved. This beam really isn’t a collector. It appears it is being used to transfer chord forces at the plan offset. WAB – 6/30/2012
Reference AAC section 23.10.104.8.
7) FRAMING PLANS CONTINUED
A) Reference sheet S235. There are two beams on grid 4 between grids B and C that appear to be drag struts, but have not been indicated as such. Please clarify.
Item remains. See item 6S. WAB – 6/30/2012
Item resolved. WAB – 8/29/2012
B) Reference sheet S236. There is some overlapping text between grids M and N and 3 and 4. Please revise.
Item resolved. This has been corrected. WAB – 6/30/2012
C) Reference sheets S236 and S234. There is a beam between grids K and L and spanning from 4 to 4.5 that may be a drag strut, but has not been indicated as one. Please clarify.
Item resolved. It appears the load at the balcony level to the brace on grid K.6 is relatively small, and the connections shown on sheets S517 are sufficient to transfer this load. WAB – 6/30/2012
D) Reference sheet S246. There is a beam on grid 4 spanning between grids F and G that appears to be a drag strut, but it has not been indicated as one. Please clarify.
E) Reference sheet S246. There are two beams near grid 3 and spanning from grids K to L.5 have been indicated as drag struts. The strut appears to start in the last third of the diaphragm. Please verify if these are struts and if they are, please clarify why the strut doesn’t extend the length of the diaphragm.
Item resolved. These beams are for force transfer around the opening. They are not collectors. WAB – 6/30/2012
F) Reference sheet S246. There is a braced frame between grids 1 and 2 and F.9 and G.3 that appears to have drag struts connected to it, but these struts stop at grid G.8. Are the rest of the beams on this “line” and along the “curve” between grids H and L.5 and 1.2 and 2.9 supposed to be drag struts? Please clarify.
Item resolved. The loads on the struts on this line are small enough that the standard beam connection has sufficient capacity to transfer the required loads. WAB – 6/30/2012
G) Reference sheet S251. There is a note near grid 9 that references sheet S404 for beams and connections this line. Sheet S404 shows the elevation of the frame on grid 4. Please revise.
H) Reference sheet S251. The plan appears to show more framing on grid 9 between grids A and C, but it is not clear if there is framing here or not. There is one beam called out as a W24X176 that appears to span from B to C, but there appears to be other elements shown, but not indicated. Please clarify.
Item resolved. The extra framing is shown due to a BIM software issue. Framing for this grid is best seen in the elevation. WAB – 6/30/2012
I) Reference sheet S251. There is a W27X84 near grid F spanning to grid 12 that appears to be a drag strut, but has not been indicate as one. Please clarify. It is also not clear how this beam is supported. Please clarify.
Item resolved. This beam is not a drag strut. No strut connection required. WAB – 6/30/2012
J) Reference sheet S252. There is a note that references S404 for beams and connections this line. Sheet S404 is the grid 4 frame, and not the grid 9 frame. Please revise.
K) Reference sheet S252. There appears to be some framing shown on grid 9 between grids L.5 and N that is shown, but not indicated. Is there supposed to be framing here? Please clarify.
L) Reference sheet S253. There appears to beams on grids 4 and 9 and between grids A and C that appear to be shown, but not indicated. Please clarify.
M) Reference sheet S253. The HSS near grid E appear to be drag struts/collectors, but have not been indicated as such. Please clarify.
Item resolved. The loads on E at this level are small. The HSS drag connection shown on sheet S521 has more than enough capacity to transfer the required loads. WAB – 6/30/2012
N) Reference sheet S253. There are two beams on grids 4 and 9 between grids C and D.9 that appear to be drags struts, but they have not been indicated as such. Please clarify.
Item resolved. The elevation indicates detail 2 on sheet S512 typical for the beam connection at this elevation. WAB – 6/30/2012
O) Reference sheet S254. None of the beams on grids 4 and 9 have been indicated as drag struts. Are these beams not drag struts at this elevation? Please clarify.
P) Reference sheet S254. There is a note on grid 9 between grid F and G that references sheet S404 for beams and connections this line. Sheet S404 has the grid 4 elevation. Please revise.
Q) Reference sheet S255. There is a beam on grid D spanning from 1 to 2 that has been indicated as a drag strut. Is this beam a drag strut? Please clarify. If it is a drag strut the other two beams on this line should be indicated as drag struts as well.
Item resolved. This line isn’t a collector line. WAB – 6/30/2012
R) Reference sheet S255. There is a beam on grid 2 between grids C and D that appears to pass over the column on grid C. Is this the intent or should there be a cantilever beam similar to the W12X16 on grid 1.3. This also occurs at grids C/3.
Item remains. Reference detail 20 on sheet S511 of the drawings. Please clarify how the beam is restrained for rotation as required by AISC 360-05 section 6.3. WAB – 6/30/2012
Item resolved. Response accepted. Please also note that this detail is not detail 14 on sheet S511. WAB – 8/29/2012
S) Reference sheet S255. There are two beams on grid 4 between grids C and D.6 that appear to be drag struts, but they haven’t been indicated as such. Please clarify.
T) Reference sheet S255. There is a beam near grid E that cantilevers from grid 1 to the south (W33X130). Please verify that this beam is not a drag strut.
Item remains. Response accepted; however please verify the detail provided at this location applies. It is not clear that the column is in line with the beams here. WAB – 6/30/2012
Item resolved. This is an affect of the BIM software. WAB – 8/29/2012
U) Reference sheet S256. There are beams on “this curve” between grids K and L.5 and 2 and 3 that have not been indicated as drag struts, but they appear to be drag struts. Please clarify. Please also note that the drag struts appear to stop at grid H.5 on “this curve.” Is this the intent or should the drag struts extend to grid G.5.
Item remains. The W24X55 between grids K and L on “this curve” appears to have between 131 and 183 kips of axial load. The standard beam connection does not appear to have sufficient capacity to transfer this load. Please verify. WAB – 6/30/2012
Item remains. The response is not clear. The loads indicated in the comment are directly from ETABS. Collectors do not generally transfer loads into diaphragms. Generally diaphragms transfer loads to the collectors. It seems in this case the load path is from the diaphragm to the W24X55, and then the load is collected to the braced frame on grid 1.7. Please clarify the response. WAB – 8/29/2012
V) Reference sheet S256. There are beams shown on grid 4 between grids L.5 and N that do not appear to have a size called out. Please clarify.
Item resolved. Use elevation for beams on grids 4 and 9. WAB – 6/30/2012
W) Reference sheet S256. Please verify whether the beams between grids F and G (running parallel to these grids) are supposed to be drag struts or not. They are in line with the frame on this line. This applies on sheet S255 as well for the same line.
Item resolved. The braced frame line is on grid E. Not between F and G. WAB – 6/30/2012
X) Reference sheet S263. There is framing shown on grids 4 and 9 that do not appear to have sizes indicated. These sizes do appear to be indicated on the elevations on sheet S403 and S404. Please provide the sizes on the plans or reference the appropriate elevation on each line. Please note that grids A through F framing does not appear to be shown on the elevation on grid 4 either.
Item resolved. Use the elevations for the framing on grids 4 and 9. WAB – 6/30/2012
Y) Reference sheet S263. There is a note near grid 5 and between grids D and E that references “this curve.” This note probably doesn’t apply. Please clarify.
Item resolved. This note has been removed. WAS – 6/30/2012
Z) Reference sheet S264. There are two details cuts on this sheet that are missing their references; on grid N near grid 5 and between grids J and K and spanning from grid 8 to 9. Please clarify.
Item resolved. These references appear to have been removed. WAB – 6/30/2012
Reference AAC section 23.10.104.8
8) FRAMING PLANS CONTINUED
A) Reference sheet S264. There are three beams on grid N from grids 5 to 8 that have double members indicated. Please clarify.
B) Reference sheet S264. As with the previous sheet, there are beams along grids 4 and 9 that have not been indicated. Please indicate these beams on the plans or reference the elevations for this information.
Item resolved. Use the elevations for these frames. WAB – 6/30/2012
9) ELEVATION DRAWINGS
Reference sheets S401 through S412 of the drawings. Please note that several of the elevations do not have reference elevations indicated for each level shown in the elevation. Please provide the reference elevations (i.e. detail 8 on sheet S401 only references “Level 1” and “Balcony Level” but does not indicate what the other two levels are). Please also provide the following:
A) Reference detail 2 on sheet S401. Please provide the brace sizes in the elevation. It does not appear as if this information was provided anywhere else.
Item resolved. This item is no longer applicable as these braces have been eliminated from the project. WAB – 6/30/2012
B) Reference detail 4 on sheet S401 and sheets S231 and S235. Please clarify the location of these braces on sheet S401. It appears from the framing plans the braces are on grid C. The elevation indicates the braces on grids B.7 and C.5. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Please also note that at the balcony level the beams run perpendicular to the beams on both of the braces shown and to brace the bottom chord as shown in detail 6 on sheet S512 would require the brace to be 20+ feet long (brace would be to the W21X44 on grid D for the B.9 brace and to a same size beam on grid D for the brace on grid C) which would limit both the strength and stiffness of the L3X3X1/4 indicated in the detail. Another option would be to brace off to a perpendicular beam, but this should be clarified in the detail, and a maximum length of the L3X3X1/4 should be indicated. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 6/30/2012
Item remains. The response seems to indicate that the wide flange beams will be used to brace the flanges; however unless the beam is at the location of the brace intersection it can not be counted as the brace at the intersection. Please clarify. The wide flanges can be used as intermediate bracing as required by section 13.4.a(2). WAB – 8/29/2012
C) Reference detail 7 on sheet S401 and sheet S232. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 6/30/2012
Item remains. The design of the angle must consider the effects of the eccentric loading of the angle (angle loaded on one leg, and not through centroid) or the slenderness factor of the angle must be determined per AISC 360-05 section E5. Please clarify. WAB – 8/29/2012
D) Reference detail 8 on sheet S401. There is a W21X55 beam above the “Balcony Level” that has a two story X brace framed into it. The top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2). It is not clear where this beam is on the framing plans. The reviewer was unable to locate it so this bracing may be indicated on the plans. Please clarify.
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. Please clarify where this beam is located in plan as it appears to be in between the low roof and balcony levels. If so both top and bottom flanges must be braced. Please also note that the brace for this beam may have a long unbraced length to get it to the low roof. WAB – 6/30/2012
Item remains. It appears that this beam is being modified with angles to stiffen the section; however it is not clear how this provides bracing for a torsion couple in the beam unless the beam ends are restrained for torsion. Please also note that by building this member up, the plastic modulus of the section increases which would increase the brace force and stiffness requirements. Please clarify. WAB – 8/29/2012
E) Reference detail 5 on sheet S401 and sheet S226. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Please also note that at the mezzanine level the beams run perpendicular to this beam and to brace the bottom chord as shown in detail 6 on sheet S512 would require the brace to be 12.75’ long (brace would be to the W12X16 near grid 2) which would limit both the strength and stiffness of the L3X3X1/4 indicated in the detail. At level 2, the brace would have to be even longer to reach the adjacent parallel beam as it is 37 feet away on grid 3. Another option would be to brace off to a perpendicular beam, but this should be clarified in the detail, and a maximum length of the L3X3X1/4 should be indicated. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 6/30/2012
Item remains. The response is accepted; however see item 9C. WAB – 8/29/2012
F) Reference detail 5 on sheet S401 and sheet S246. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. At level 2, the brace would have to be extremely long to reach the adjacent parallel beam as it is 37 feet away on grid 3. Another option would be to brace off to a perpendicular beam, but this should be clarified in the detail, and a maximum length of the L3X3X1/4 should be indicated. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 6/30/2012
G) Reference detail 6 on sheet S401 and sheet S226. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. At the balcony level both the top and bottom flange must be braced. The brace for this beam will need to be extremely long to reach the perpendicular beam which is the W30X90 on grid L.5. Even to be braced to a perpendicular beam would require a substantially long brace. Either option will severely limit the capacity and stiffness of the L3X3X1/4. Please clarify. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. Please note at the balcony level it does not appear as if there is anything to brace off to. Please clarify. WAB – 6/30/2012
Item resolved. This beam has been built up into a box beam, and the ends have been provided with torsional resistance. The beam is able to brace itself. WAB – 8/30/2012
H) Reference sheet S402 and sheet S213. It is not clear, but it appears this brace is framed into the slab on metal deck above the W21X101 beam on grid E between grids 6 and 7. If this is the case, the bottom flange of the beam at the braced intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2). This is not clear because detail 3 on sheet S521appears to show an embed plate with WHS embedded 8” which would imply the braces frames to the foundation wall; however this does not appear to be the intent. Please clarify.
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. It should also be clarify where the brace is spanning to in the case where there is no deck at the top flange. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 6/30/2012
Item resolved. The HSS has sufficient strength and stability to brace themselves. WAB – 8/30/2012
I) Reference sheet S402. There is a W27X94 that appears to be two levels above the above the “Concourse Roof” level that has a two story X connected to it. The top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2). This beam could not be located in the plans. While the elevation appears to show floor decking it is not clear that this decking is there. Please clarify.
Item no longer applicable. The brace in question has been modified due to the elimination of the swoop in the roof. WAB – 6/30/2012
J) Reference sheet S402. There are several instances where two story X braces connect to HSS struts. The top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Detail 3 on sheet S522 can not be used at the HSS struts. Please clarify the response. At the balcony level, to brace off to the adjacent parallel beam, the brace will need to be 16-20+ feet long. This will severely affect the strength and stiffness of the L3X3X1/4 brace. It is not clear what the braces can be spanned to at the level above the “concourse roof” level. It appears the high roof diaphragm or balcony levels would be the options, but this would require extremely long braces. Please clarify. Please note that it can be shown that the beam has sufficient out-of-plane strength and stiffness to ensure stability between the adjacent brace points. WAB – 6/30/2012
Item resolved. The HSS have sufficient capacity and stability to brace itself. WAB – 8/30/2012
K) Reference sheet S403 and sheet S253. There is a W24X176 beam between grids B and C on the elevation that appears to support an odd braced frame. It doesn’t really appear to be a concentric braced frame and really appears to be more of an eccentric brace. Please clarify. If this is a concentric braced frame, the top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item resolved. There has been a column added this location to the foundation which makes the brace concentric. This also eliminates the bracing of the beam flanges. WAB – 6/30/2012
L) Reference sheet S403. There is several detail cuts provided with no references. Please provide the references.
Item resolved. All of these were either removed or filled in. WAB – 6/30/2012
M) Reference sheet S403 and sheet S253. There is a W24X146 spanning between grids C and D on the elevation that has a two story X brace connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 7/1/2012
Item remains. The design of the angle must consider the effects of the eccentric loading of the angle (angle loaded on one leg, and not through centroid) or the slenderness factor of the angle must be determined per AISC 360-05 section E5. Please clarify. WAB – 8/30/2012
N) Reference sheet S403 and sheet S253. There is a W24X94 spanning from grid D to the first set of leaning columns on the elevation that has a two story X connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
O) Reference sheet S403. There is a W21X93 spanning from grid G to H at the “Concourse Roof” elevation that has a two story X brace connected to it. The top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2). This beam could not be located in the plans so it is not clear if anything braces either flange.
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Please also note that this beam is between the low roof and balcony levels so both the top and bottom flange must be braces. The brace length will also need to be extremely long to brace off to a level with a diaphragm. It can also be shown that the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 7/1/2012
Item resolved. This beam has been built up into a box beam and the ends have been modified to support torsion. WAB – 8/30/2012
P) Reference sheet S403 and sheet S252. There is a W24X94 spanning from grids K.5 to L at the “Low Roof” elevation that has an inverted V braced frame connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. Reference AISC 341-05 section 13.4.a(2). It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise.
Please note that there are several instances between the high and low roofs where brace intersections occur at HSS struts. These struts need to have both top and bottom flanges braced or it must be shown that the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Please note that the braces for these HSS will need to be extremely long to reach diaphragms to be braced to. WAB – 7/1/2012
Item resolved for this portion. The HSS struts have sufficient capacity and stability to brace themselves. WAB – 8/30/2012
Q) Reference sheet S404. There is a detail cut at Grid B/”Balcony Level” that references detail 1 on sheet S512. This detail does not appear to apply at this location. Please verify.
Item resolved. It appears the intent is to apply this connection above the balcony level connections on this grid unless noted otherwise. WAB – 7/1/2012
R) Reference sheets S404 and S255. There is a beam that spans from grids C to D at the “Low Roof” elevation that has a two story X brace connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
S) Reference sheets S404 and S255. There is a beam that spans from grids D to the first set of leaning columns that has an inverted V brace connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
T) Reference sheet S404. There are several two story X braces connected to HSS struts between the high roof and low roof elevations. The top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Detail 3 on sheet S522 can not be used at the HSS struts. Please clarify the response. These struts need to have both top and bottom flanges braced or it must be shown that the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Please note that the braces for these HSS will need to be extremely long to reach diaphragms to be braced to. WAB – 7/1/2012WAB – 6/30/2012
Item resolved. The HSS struts have sufficient capacity and stability to brace themselves. WAB – 8/32/2012
U) Reference sheet S404. There is an inverted V brace between grids G and H and between the “Mezzanine Level” and “Balcony Level” that does not appear to be concentric. Please clarify. If it is concentric, the top and bottom flanges of this beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
Item remains. Response accepted; however please provide substantiating data showing the brace has sufficient strength and stiffness to provide the necessary restraint. It is recommended that the new detail indicates that it applies at each brace intersection unless noted otherwise. WAB – 7/1/2012
Item resolved. The column has been modified to extend to this level so it is no longer a V or inverted V brace. WAB – 8/30/2012
V) Reference sheet S404 and S256. There is a W24X94 spanning from grids K.5 to L at the “Low Roof” elevation that appears to have an inverted V brace connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
W) Reference sheet S404 and S256. There is a W24X94 beam spanning from grids L to L.7 that appears to have a V brace connected to it. The bottom flange of the beam at the brace intersection must be braced per AISC 341-05 section 13.4a or it must be shown the beam has sufficient out-of-plane strength and stiffness to ensure stability between adjacent brace points. Spacing of lateral bracing must also meet AISC 341-05 section 13.4a(2).
X) Reference sheet S411. There are two detail cuts on grid G that overlap each other. Please clarify.
Item resolved. This has been clarified. WAB – 7/1/2012
Y) Reference sheet S411. There is a detail cut on the truss bottom chord that is missing the reference. Please provide.
Item resolved. These cuts have been removed or filled in. WAB – 7/1/2012
Z) Reference sheet S411. Please provide location of both the bottom and top chord splices.
Item resolved. Response accepted. WAB – 7/1/2012
10) FRAMING DETAILS
A) Reference details 1 and 2 on sheet S412. Please clarify what supports the concrete panels at the base of the seating. Are the panels going to be designed to be self supporting here? Please clarify.
B) Reference detail 4 on sheet S511. This detail provides the moment connection detail where the beam connects to the column flange. Please provide, or indicate where in the drawings it has been provided, a detail showing the condition of the beam into column web moment connection.
Item resolved. This detail is on sheet S511 (detail 9). WAB – 7/1/2012
C) Reference detail 11 on sheet S511. This detail makes reference to detail 4 on sheet S5.12. This sheet does not exist. Please note that detail 4 on sheet S512 doesn’t appear to apply either. Please clarify.
Item resolved. This note has been deleted. WAB – 7/1/2012
D) Reference detail 13 on sheet S511. This detail makes reference to detail 4 on sheet S512 for “W BMS NOTED IN PLAN AS DRAG STRUTS,” but this detail does not appear to apply. Please clarify.
Item resolved. This note appears to have been deleted. WAB – 7/1/2012
E) Reference detail 15 on sheet S511. This detail indicates the column as a girt. Please revise.
Item resolved. This has been corrected. WAB – 7/1/2012
F) Reference detail 20 on sheet S511. Please clarify the intent of this detail. There is no information provided.
Item resolved. This detail has been deleted. WAB – 7/1/2012
G) Reference detail 6 on sheet S512. This detail references sheet S5.13. This should be S513. Please revise.
H) Reference detail 7 on sheet S512. It is not clear where this detail applies. Please clarify. Please note that it is not possible to fabricate this detail without additional information like the location of the cut. Otherwise the “WT CUT FROM W33X118” can not be fabricated correctly.
I) Reference detail 9 on sheet S512. It doesn’t appear as if the embedment of the post installed anchor at the top of the detail has been provided. Please provide.
Item remains. The response references the WHS anchors. The comment was about the post installed anchor at the deck angle. WAB – 7/1/2012
Item resolved. Response accepted. WAB – 8/30/2012
J) Reference details 8 and 9 on sheet S513. Please clarify the size of the WT shown in this detail or indicate where in the drawings the size of this WT can be located.
Item resolved. These WTs are indicated on sheet S412. WAB – 7/1/2012
K) Reference detail 9 on sheet S514. The bearing notch plate has been indicated as 1/14X2’-2 ½”. This doesn’t appear correct. This probably should be 1 ¼”X2’-2 ½”.
Item no longer applicable. This detail has been deleted. WAB – 7/1/2012
L) Reference details 17 and 18 on sheet S514. Please clarify the intent of these details. There is no information provided in either.
Item no longer applicable. These details have been completely revised or removed. WAB – 7/1/2012
M) Reference detail 18 on sheet S514. There is a detail cut in this detail that is missing the reference. Please provide.
Item no longer applicable. This detail has been completely revised. WAB – 7/1/2012
N) Reference detail 5 on sheet S515. The bearing plate has been indicated as 11/2. It appears this should be 1 ½”.
Item no longer applicable. This detail has been completely revised or removed. WAB – 7/1/2012
O) Reference detail 6 and 7 on sheet S515. Note 1 in detail 7 on sheet S515 indicates to trim the flange to 8 ¼”. It appears that detail 6 on sheet S515 indicates to trim the flange to 8 ½”. Please clarify.
P) Reference detail 8 on sheet S515. There is a note that states “48 DIA SHEAR PLATES 12EA FACE OF EA GL.” Please clarify this note.
Q) Reference details 9 and 10 on sheet S515. Note 1 in detail 9 indicates to trim the flange to 8 ¼”. Detail 10 appears to indicate to trim the flange to 8 ½”. Please clarify.
R) Reference details 16 and 17 on sheet S515. Note 1 in detail 17 indicates to trim the flange to 8 ¼”. Detail 10 appears to indicate to trim the flange to 8 ½”. Please clarify.
S) Reference details 19 and 20 on sheet S515. Note 1 in detail 19 indicates to trim the flange to 8 ¼”. Detail 20 appears to indicate to trim the flange to 8 ½”. Please clarify.
T) Reference detail 6 on sheet S517. The intersection of the WF beam and the built up beam is not clear. Please clarify this detail.
U) Reference detail 10 on sheet S517. There are a couple of welds in this detail that are not clear; the partial pen with backing fillet at the HSS to leaning column, and the PL ¾ to end plate weld. These appear to call for a partial pen weld without giving a size unless the size of the back up fillet is meant as the size of the partial pen. Please clarify.
V) Reference detail 2 on sheet S521. The detail references detail 11 on sheet S512 for the angle, but this reference does not appear to be correct. It appears this may be detail 6 on sheet S512. Please clarify.
W) Reference detail 4 on sheet S521. The notes in this detail references both sheets S6.01 and S3.02. Neither of these sheets exist. Please revise.
X) Reference detail 7 on sheet S521. This detail has a note that means to reference a sheet, but doesn’t. Please revise.
Y) Reference detail 8 on sheet S521. This detail reference sheet SS321 for the brace connection. It appears this should be S521.
Item remains. The response and correction are accepted; however this detail gives a throat thickness on a flare bevel weld. Flare bevel welds do not have throat thicknesses. Please revise. WAB – 7/1/2012
Item remains. The response indicates that this was corrected, but it doesn’t appear as if it has been. Please revise. WAB – 8/30/2012
Z) Reference detail 12 on sheet S521. This detail reference sheet S6.01 which does not exist. Please revise.
11) FRAMING DETAILS CONTINUED
A) Reference detail 13 on sheet S521. This detail references sheet SS321 which does not exist. It probably should be S521.
B) Reference detail 17 on sheet S521. This detail has a note that means to reference a sheet, but doesn’t. Please revise.
C) Reference detail 1 on sheet S601. This schedule indicates “BRACE CONN REINF SEE ?/S?.” Please clarify the reference.
D) Reference sheet S211. There appears to be a condition where a steel beam connects into the side of another steel beam right at the connection point of the beam to concrete wall (grid 10 between grids E and F). Please provide a detail showing how this condition is to be framed. It appears this applies to the beam on grid 3 between E and F as well.
Item remains. The response indicates that these beams have been moved to accommodate a standard beam to beam connection, but it doesn’t appear as if this has been done on the plans. Please clarify. WAB – 7/1/2012
Item resolved. The beams appear to have been moved slightly on the plans. WAB – 8/30/2012
E) Reference sheet S212. There appears to be a W21X121 on grid G.6 spanning from grid 11 to just past grid 12. Does this beam frame over the top of the concrete pier below or does it frame into the side of the pier? Please clarify. If framed over the top of, a detail showing this condition needs to be provided.
Item resolved. The framing in this area has been revised. WAB – 7/1/2012
F) Reference sheet S212 (and other sheets showing the level 1 seating area). Please provide details showing how the level 1 seating area is to be constructed.
G) Reference sheet S232. There is a condition where it appears a W12X30 beam passing over or under a W30X108 beam (on grid 9 between grids G and H). Please clarify this condition.
Item resolved. This has been corrected on the framing plan. WAB – 7/1/2012
H) Reference details 1, 2 and 3 on sheet S412. Please provide a dimension to where the slope for the seating area starts.
12) FRAMING DESIGN COMMENTS
Reference the drawings and calculations. Please note that per the engineer, the wood has been removed from the project so all wood design has been ignored in the reviewed. Please provide the following:
A) Reference pages 809 and 811 of the calculations. Please clarify why the tributary width of these beams have been taken as 3.125 ft. They appear to have the same tributary width as the beams before it.
Item no longer applicable as the wood beams have been eliminated. WAB – 7/1/2012
B) Reference pages 810 and 812 of the calculations. Please clarify why there is 0-psf snow load on these beams and why the tributary width has been taken as 3.125 ft. These beams are roof beams that appear to have snow load on it, and they appear to have a similar spacing as the beams on pages 805 through 808.
C) Reference pages 804 and 809 through 812 of the calculations. Please clarify how the point loads applied to the beams were determined.
D) Reference page 904 of the calculations. Please clarify why the live load for the platform has been taken as 25-psf.
Item remains. Please submit an alternate means and methods form to the Building Official for approved. Elevated platforms are required to be designed for 60-psf live load per IBC table 1607.1. WAB – 7/1/2012
Item resolved. Platform to be designed as a catwalk for 40-psf live load. WAB – 8/30/2012
E) Reference page 904 of the calculations. There appears to be a catwalk and platform system within the roof framing. This hasn’t been listed as a deferred submittal. Please clarify this framing or indicate as a deferred submittal.
Item resolved. This has now been indicated as a deferred submittal. WAB – 7/1/2012
F) Reference page 904 of the calculations. The loading indicated is confusing. The dividing by two for two trusses is clear. The second factor of two seems to imply that each truss will have two hanging loads of 15 kips each, but the note appears to indicate a single 15 kip load applied to various locations on the truss from grids J to M, but then the total hanging load from trusses indicates 45,000 lbs each. Please clarify.
G) Reference page 906 of the calculations. This page indicates a 25 kip point hanging load and a 15 kip hanging load. The 15 kip load appears to have been developed on page 904 (see item F), however it is not clear where the 25 kip load was developed. Please clarify.
Item resolved. See the response to F. WAB – 7/1/2012
H) Reference page 603 of the calculations. When the deflection was determined it appears that only the deflection of the W21X101 was calculated. This deflection does not appear to include the deflection of the supporting frame which is likely significant. Please clarify the deflection check.
I) Please provide design of the steel plate shear walls or indicate where in the drawings this design has been provided.
Item remains. It appears that only one condition has been checked (where the height is 4.5’). There are conditions on grids G.5 and 4 that have taller heights. These walls may have lower shear in them as well, but this needs to be checked. Please also note that steel plate shear walls must be designed and detailed as required by AISC 341-05, Chapter 17. Please verify this has been done. WAB – 7/1/2012
Item remains. These need to be designed per AISC 341, Chapter 17. Please note that the permit referenced was prior to the adoption of the 2005 AISC Seismic Provisions where Special Steel Plate Shear walls were introduced. It is possible that this method was accepted even after the 2005 Seismic Provisions were adopted; however this would still not be a reason to accept the design as is. Please note that the seismic provisions are there to provide design requirements to ensure the vertical resisting element can resist the lateral seismic loads through inelastic behavior. That is one of the purposes of AISC 341. WAB – 8/28/2012
J) Please verify the design of the roof framing members for the load combinations including wind uplift. There is likely no net uplift on the main trusses, but the other members likely have net uplift. Since the bottom flange of most of the roof framing will not be braced the moment capacity for these members under the uplift condition will be substantially lower than for the dead plus snow load condition.
Item resolved. Response accepted. WAB 7/1/2012
K) Please provide the truss Staad model input and output for review. This information is required to verify the design of the connections as well.
L) Reference pages 1601 through 1607 of the calculations. Please verify that at a minimum the diaphragms, chords and collectors have been designed for a minimum of 0.2*SDS*I*wpx as required by ASCE 7-05 section 12.10. Please note that due to the redistribution of loads in ETABS it is probably that the 0.2*SDS*I*wpx controls the design of many of the diaphragms, chords and collectors. It is not clear from the referenced pages whether the loads indicated are from the ETABs model or based on the minimum required force. If the values indicated in the calculations already consider this please just provide verification for a few of the diaphragms/chords/collectors. Please note that it appears this was attempted on page 1601 for grid 4, but the scale used isn’t clear. It seems like it should be the 1354.7 kips from page 12 divided by (855+691)/1.4 times 855 which would scale the 855 kips up and not down as it appears has been done.
13) DESIGN OF BEAMS FOR UNBALANCED BRACE LOADS
Reference the elevations. The following beams appear as if they will have an unbalanced brace load that must be considered:
A) Reference detail 4 on sheet S401. The beams at the balcony level in both braced frames.
Item remains. Please provide substantiating data showing the unbalanced braced force is negligible and does not need to be considered. Since this unbalanced load must be considered in combination with the appropriate gravity loads it may not take a substantial unbalanced load to overstress the beam. Please note that the unbalance force must be determined and transferred assuming all compression braces have buckled simultaneously. WAB – 7/1/2012
B) Reference detail 7 on sheet S401. The beam at the balcony level.
Item remains. Please provide substantiating data showing the unbalanced braced force is negligible and does not need to be considered. Since this unbalanced load must be considered in combination with the appropriate gravity loads it may not take a substantial unbalanced load to overstress the beam. WAB – 7/1/2012
C) Reference detail 8 on sheet S401. The beam above the balcony level.
D) Reference detail 5 on sheet S401. The beams at the 2nd level and the mezzanine level (the one at the mezzanine level may have approximately the same brace forces at approximately the same angles so it may not require checking).
E) Reference detail 6 on sheet S401. The beams at the 2nd level and balcony level.
F) Reference detail 1 on sheet S402. The beam at the 1st level between grids 6 and 7, the beams at the balcony level between grids 4 and 5 and 8 and 9 (while the brace sizes are the same it appears the angle of the braces are different), the beams at the concourse roof level between grids 6 and 7, and the beams above the concourse roof level between grids 4 and 5 and 8 and 9.
G) Reference detail 2 on sheet S403. The beam at the balcony level between grids D and D.5, the beams above the concourse roof level between grids B and C, C and D, and D and D.3, and the beams below the high roof level between grids B.6 and C.3, and C.3 and D.2.
Item remains. Please provide substantiating data showing the unbalanced braced force is negligible and does not need to be considered. Since this unbalanced load must be considered in combination with the appropriate gravity loads it may not take a substantial unbalanced load to overstress the beam. For the balcony beam between grids D and D.5, please provide hand calculations showing how the 43.5 kip unbalanced load was determined. This doesn’t appear to be close to the unbalanced load. WAB – 7/1/2012
H) Reference detail 1 on sheet S403. The beam at the concourse roof level between grids G and H, the beams at the low roof level between grids K.5 and L and L.5 and N. Please note that it isn’t really clear where the braces at grid L.5 connect to. A detail for this condition needs to be provided, and it’s possible something needs to be done with the beam from L to L.5, and the connection of this beam to the column.
I) Reference detail 1 on sheet S404. The beams above the concourse roof level between grids C and D and D and D.5. It is very unclear how the braces are connected to the beam between grids D and D.5. It doesn’t appear as if the brace above is concentric with the braces below, and it’s not clear if the braces below are concentric. This may be an eccentric connection based on the layout shown. The beams below the high roof level between grids B.6 and C.3 and C.3 and D.2 also need to be designed for the unbalanced braced force.
J) Reference detail 2 on sheet S404. The beam at the balcony level between grids G and H. This brace connection may not be concentric. By the elevation it appears to be eccentric, and may need to be designed as such. The beam at the concourse roof level between grids L and L.5. This may not be a concentric braced frame either given its closeness to the beam/column connection. There will likely be some behavioral issues in the braced frame given this configuration.
Please provide the design of these beams for the unbalanced brace force or indicate where in the calculations this design has been provided. Where the braces sizes and angles above and below the beam are the same this unbalanced condition does not need to be considered, and the response can just state this. Reference AISC 341-05 section 13.4a.
Please provide a written response to the comments and include one copy of additional or revise calculations, and two copies of additional or revise drawings. While not required it is extremely helpful to the reviewer if the response indicates where in the submittal each comments has been addressed.
All submittals should be sent to the permit manager.
