Reviewed by: Bolen, Wayne A.                                                  Permit #: C15-1806

Phone: 343-8072                                                                       Date: 10/28/2015

Fax: 249-7393

Email: BolenWA@muni.org

Permit Manager: Tony Barganier

Phone: 343-8339

Email: BarganierTA@muni.org

Project: Courtyard at Marriott

Review Number: 359449

____________________________________________________________________________________

PERMIT STATUS

10/28/2015 – Review complete. Comments issued.

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. SITE CLASS

Reference the geotechnical report and the seismic calculations. It appears that the geotechnical report at the seismic design has been based on Site Class E. Please justify this classification. ASCE 7-0 5 section 20.3.3 requires Site Class E to be based on the properties of the top 100 feet of soil on the site. It appears the soil logs only go to 31.5'. There does not appear to be enough data to justify the Site Class E designation. While this assumption is fine for footing connectivity requirements and other prescriptive foundation requirements is not fine when determining the loads because it leads to a decrease in the required seismic design forces that can not be justified with the given data. Please revise and resubmit. A limited seismic review has been performed since the loading will be off by 11%. Please note that the Site Class has been indicated as Site Class D on sheet S001 of the drawings.

2. OPEN FRONT DIAPHRAGMS

Reference pages L-3, L-10, L-17 and L-24 of the calculations. It appears that the intent of the design in the longitudinal direction is to design the structure as a series of open front diaphragms. It appears that most of the open front diaphragms are not permitted. The Special Design Provisions for Wind and Seismic (SDPWS) section 4.2.5.1.1 limits the length of open front diaphragms to 25', and the aspect ratio of such diaphragms to 0.67:1. It appears that most of the open front diaphragms provided for lateral loads in the longitudinal direction exceed one of these two limitations. Please clarify or revise and resubmit. Please also keep in mind that open front diaphragms are rigid diaphragms and must be design accordingly. The lateral review in the longitudinal direction is even more limited than the rest of the structure as this comment will likely affect the load distribution substantially in this direction.

3. SEISMIC LOAD DISTRIBUTION

Reference pages L-3 through L-28 of the calculations. It doesn't appear as if the seismic distribution in the "Y" direction has been done correctly. It appears that instead of calculating loads tributary to a resisting line that where there are two walls on a line that the building was divided in half, and the loads were based on the tributary area to the wall assuming the upper wall supports the upper half while the lower wall supports the lower half of the building. For example on line 3, instead of a single resisting line with a tributary width of 20.4 feet, the upper wall has been designed with a tributary width of 20.4 feet and the lower wall has been designed with a tributary width of 27.1 feet because the next wall over at the top is closer than the one at the bottom. This is not correct. The tributary width to both walls is the same. It should be apparent that the method used is incorrect because the uniform line load to each wall is different which would mean the deflection is each wall is different which is not possible since they are on the same line. Please revise the load distribution and resubmit. The lateral review is once again limited because of the distribution issue. Reference the SDPWS section 4.2.5.

In the "X" direction it is likely the distribution will significantly change due to comment 2; however if there is a way to justify the open front diaphragms then the loads must be distributed based on stiffness of each wall and the diaphragms which means the deflections of the walls and diaphragms must be determine and the loads distributed based on relative stiffness. Reference SDPWS section 4.2.5.1.1 and ASCE 7-05 section 12.8.4. If the open front diaphragms remain it must also be shown that no torsional irregularities are present. If a torsional irregularity is present, the equivalent lateral force procedure of ASCE 7-05 section 12.8 would not be permitted per ASCE 7-05 table 12.6-1 and the modal response spectrum analysis or seismic response history procedure will be required to analyze the structure for seismic forces.

4. DESIGN OF CHORDS, COLLECTORS, AND DRAG STRUTS

Reference pages L-40 and L-41 of the calculations and the drawings. Please provide design of chords, collectors and drag struts for the diaphragms as required by ASCE 7-05 section 12.10. Please provide detailing around openings in the diaphragms as required by ASCE 7-05 section 12.10.1 and IBC section 2305.1.1. Additional comments may be generated from the response to this comment.

5. LATERAL AT ROOF

Reference sheets S141a and S141b and the details on sheets S521 through S523 of the drawings. Please provide the following:

A. Reference sheet S141a. Please provide detailing around the opening at the elevator as required by IBC section 2305.1.1 and ASCE 7-05 section 12.10.1. This also applies to the stair opening on sheet S141b.

B. Please provide chords, collectors and drag struts at each resisting line as required. Chords are required at the front and back of diaphragms to transfer the tension and compression loads generated from bending in the drawings. Collectors are required to transfer loads that are generated in one portion of the structure to another point in the structure. Drag struts are require where shear loads are required to be transferred from one point in the structure into the diaphragm of another part of the structure. For a great reference on these elements see "The Analysis of Irregular Shaped Structures" by R. Terry Malone and Robert W. Rice. Please note that additional comments may be generated from the response to this comment. Detail 7 on sheet S522 appears to show a condition that may apply at the beams on each side of the corridor, but there doesn't appear to be a reference on the roof framing plan calling out this detail. The intent may be to apply it at all header location, but this is not clear. Response to comment 2 may affect the collector/chord/drag strut requirements.

C. Reference detail 13 on sheet S512. Please provide a lateral load path from the diaphragm to the shear walls below. Neither the detail nor the schedule appears to call out a connection of the blocking to the top plate below. There does appear to be an attachment of the rim to top plate, and it is possible that the intent is to use this connection at blocking as well.

D. Reference page L-2 of the calculations. While seismic controls the over all forces at most levels and overall it appears that seismic controls overturning and shear, at the roof level it's possible that wind controls the overturning because of wind uplift on the roof counteracting the roof dead load. Please verify that wind does not control the roof level for overturning. It is also not clear how the wind load at the roof level was determined. Please verify that when the wind load at the roof was determined that the pressure on the parapet was taken as required by ASCE 7-05 section 6.5.12.2.4.

E. Reference details 1 and 2 on sheet S523. Please indicate edge nailing and boundary nailing for the connection of the shear wall sheathing and diaphragm sheathing to the blocking respectively. This provides the lateral load path from the roof diaphragm to the shear wall sheathing. Reference AAC section 23.10.104.8 and ASCE 7-05 section 12.1.3.

F. Reference sheet S141a of the drawings and page L-9 of the calculations. There are shear walls shown starting at grids C/10.3 and D/10.3 in the drawings; however these are not included in the shear wall design shown on page L-9 of the calculations. Please clarify. Please note that while including this wall in the drawings and not including in the calculations may be conservative for the shear wall design, it may affect collector designs. Reference ASCE 7-05 section 12.8.4.

G. Reference detail 10 on sheet S522. This detail references the plan for the shear wall from the high to low roof; however this information does not appear to be on the plan. Please clarify. Reference ASCE 7-05 section 12.1.3.

H. Reference details 1 and 2 on sheet S523. Please indicate edge nailing for the sheathing to 2X6 blocking connection as the blocking acts as the shear wall edge. Reference ASCE 7-05 section 12.1.3.

6. LATERAL AT 4TH FLOOR

Reference sheets 131a and 131b and the details on sheets S511 through S513 of the drawings. Please provide the following:

A. Reference sheet S131b. There are two shear walls shown between grids D and E in the left/right direction shown on the drawings that were not considered shear walls in the calculations. Please clarify. Please note that having those two walls as shear walls drastically affects the lateral distribution of loads and the lateral design would have to be redone. This comment applies to the lower levels as well.

B. Please provide chords, collectors and drag struts at each resisting line as required. Chords are required at the front and back of diaphragms to transfer the tension and compression loads generated from bending in the drawings. Collectors are required to transfer loads that are generated in one portion of the structure to another point in the structure. Drag struts are require where shear loads are required to be transferred from one point in the structure into the diaphragm of another part of the structure. For a great reference on these elements see "The Analysis of Irregular Shaped Structures" by R. Terry Malone and Robert W. Rice. Please note that additional comments may be generated from the response to this comment. Detail 7 on sheet S522 appears to show a condition that may apply at the beams on each side of the corridor, but there doesn't appear to be a reference on the roof framing plan calling out this detail. The intent may be to apply it at all header location, but this is not clear. Response to comment 2 may affect the collector/chord/drag strut requirements. This comment applies to the lower levels as well.

C. Reference sheet S131b. Please provide dimensions to hold downs that do not occur at the ends of a wall. These must be dimensioned so they can be located correctly. Reference AAC section 23.10.104.8. This comment applies to the lower levels as well.

D. Reference sheet S131b. There is a hold down at the intersections of grids D and 24. This appears to be a shared hold down (this hold down appears to transfer overturning forces in both orthogonal directions). Please provide a detail showing how this hold down is framed to be able to transfer loads in from both directions. Reference ASCE 7-05 section 12.1.3 and SDPWS sections 4.3.6.4.2 and 4.3.6.4.4. There could be other locations where a shared hold down is used. This comment applies to those location as well. This comment also applies to the lower levels.

E. Reference sheet S131a. Where shear walls extend from the interior of the building to the exterior of the building please provide a detail at the transition between the interior and exterior show the lateral load path for shear and overturning forces. Typically the exterior walls of the building are constructed first with the interior walls to follow. This means there will likely be a joint at the transition that needs to be detailed. This occurs at several locations. Reference ASCE 7-05 section 12.1.3. This comment applies to the lower levels as well.

F. Reference sheet S131a. There are shear walls shown below grid D at grids 11 and 12 on the drawings; however these walls are not shear walls in the calculations. Please clarify. This also applies to the shear wall shown on sheet S131a above grid C at grid 11. This comment applies to the lower levels as well.

G. Reference sheet S131a. There are shear walls shown on grids C and D starting at grid 10.3 on the drawings; however these walls are not shear walls in the calculations. Please clarify. This comment applies to the lower levels as well.

H. Reference sheet S131a. There is a shear wall above grid C at grid 8 shown on the drawings that is not designed as a shear wall in the calculations. Please clarify. This comment applies to the lower levels as well.

I. Reference sheet S131a. There is a shear wall above grid C at grid 6 shown on the drawings that is not designed as a shear wall in the calculations. Please clarify. This comment applies to the lower levels as well.

J. Reference sheet S131a. There is a double hold down shown for the shear wall below grid D and on grid 3 near grid D. Please verify this is the intent. This comment applies to the lower levels as well.

K. Reference sheet S131a. There is a hold down on grid C near grid 1.5 that appears to be shown in the opening adjacent to the shear wall it is intended to be in. Please revise to show in the shear wall. This comment applies to the lower levels as well.

L. Reference sheet S131a. There are several instances of interior hold downs being indicated as straps. Please verify this is the intent and that it is not intended for these to be ATS hold downs. Installing interior strap hold downs required slotting of the diaphragm and are generally more problematic to install. This comment applies to the lower levels as well.

M. Reference detail 6 on sheet S511. Please indicate diaphragm boundary nailing at the interior shear wall details. Diaphragm boundaries occur at the vertical resisting elements, and if it is not clarified that boundary nailing is required at the shear wall lines it is possible that field nailing will be provided.

7. LATERAL AT 3RD FLOOR

Reference sheets S121a and S121b and the details on sheets S511 through S513 of the drawings. Please provide the following:

A. Reference sheet S121b. The two shear walls on grids C and D that start at grid 14.3 are discontinuous. Elements that support discontinuous shear walls must be designed to the load combinations including the overstrength factor. Please provide this check or indicate where in the calculations this check has been provided. Reference ASCE 7-05 section 12.3.3.3.

8. LATERAL AT 2ND FLOOR

Reference sheets S111a and S111b and the details on sheets S511 through S513 of the drawings. Please provide the following:

A. Reference sheet S111b. The shear wall above the 2nd floor on grid D starting at grid 22.3 is discontinuous as the shear wall below is shorter by several feet. Element supporting discontinuous shear walls must be designed to the load combinations including overstrength. Please provide this check or indicate where in the calculations the check has been provided. Reference ASCE 7-05 section 12.3.3.3.

B. Reference sheet S111a. Please clarify the lateral support for the canopy/trellis at the plan south end of the building. Reference ASCE 7-05 section 12.1.3.

C. Reference sheet S111a. Please clarify the lateral support for the low roof and trellis at the plan north end of the structure (Media Pod room and trellis to the east of it). Reference ASCE 7-05 section 12.1.3.

D. Reference sheet S111a and pages SB-1 through SB-19 of the calculations. The steel beam on grid 14 below grid D is supporting a discontinuous shear wall. Elements supporting discontinuous shear walls must be designed to the load combinations including the overstrength factor. Please provide this check or indicate where in the calculations this check has been provided. Reference ASCE 7-05 section 12.3.3.3.

E. Reference sheet S111a and pages SB-1 through SB-19 of the calculations. Many of the steel beams in along each side of the corridor appear to support discontinuous shear walls. Element supporting discontinuous shear walls must be design to the load combinations including the overstrength factor. Please provide this check on the beams that support discontinuous shear wall or indicate where in the calculations this check has been provided.

F. Reference sheet S111a and pages SB-1 through SB-19 of the calculations. The steel beam on grid 13 above grid C is supporting a discontinuous shear wall. Elements supporting discontinuous shear walls must be designed to the load combinations including the overstrength factor. Please provide this check or indicate where in the calculations this check has been provided. Reference ASCE 7-05 section 12.3.3.3.

G. Reference sheet S111a and page L-32 of the calculations. There should be a shear wall on grid C starting at grid 5 per the calculations, but it does not appear as if this has been indicate as a shear wall on the drawings. Please clarify.

H. Reference sheet S111a. There is a CMSTC call out near grid 2 on grid C. This strap is not shown in the correct location. It should be located on the grid 2 shear wall. Please revise.

I. Reference sheet S111a and pages SB-1 through SB-19 of the calculations. There is a steel beam on grid 13 below grid D (W14X34) that appears to be supporting a discontinuous shear wall. Element supporting discontinuous shear walls must be design to the load combinations including the overstrength factor. Please provide this check on the beams that support discontinuous shear wall or indicate where in the calculations this check has been provided.

J. Reference detail 3 on sheet S603. Where bolted connections transfer seismic forces they must be installed as fully pretensioned with their faying surface prepared as Class A slip critical or better as required by AISC 360-05 section 7.2. Please indicate this requirement on the drawings. Where ever the steel beams act as a collector the bolts will transfer seismic forces.

9. LATERAL AT FOUNDATION

Reference sheets S101a and S101b and the details on sheets S501 through S502 of the drawings. Please provide the following:

A. Reference the foundation plans and pages FN-1 through FN-10 of the calculations. It is not clear how the uplift from the hold downs are resisted at the foundation level. Is grade beam action being used or is concrete mass being used. Please clarify. In either case, please provide calculations showing the uplift can be resisted at the foundation level or indicate where in the calculations this design has been provided (where grade beam action is used provide design of grade beams and where mass is used show there is sufficient mass). Reference IBC section 1808.3.

B. Reference the foundation plans and pages FN-1 through FN-10. Please clarify how the lateral shear forces are resisted at the foundation level. If the slab on grade it to be used to resist lateral forces from seismic it must be designed to meet the requirements of ACI 318-08 section 21.12.3.4.

C. Reference sheet S101b. On grid 22 near grid E, it appears that the ATS hold down is not continuous to the foundation. Is there some sort of load path from the ATS system to the steel column? Please clarify. Please also provide a detail showing how overturning forces from the shear walls above the 1st floor are transferred into the steel column. It does appear there is a calculation for anchors of steel columns that appear to include uplift forces on page L-42 through L-53; however these calculation do not appear to consider the non ductile yielding factor of ACI 318-08 section D.3.3.6. Please clarify. If there is a load path from the ATS system to the steel column please provide a detail showing this load path. This issue appears to occur on multiple ATS rods that appear to stop at the 2nd floor level.

D. Reference sheet S101a. The shear wall on grid C starting at grid 14 requires an HDU11 hold down per the calculations. It appears that an HDU 8 has been provided at one end and nothing except a steel column has been provided at the other. Please clarify.

E. Reference sheet S101a. There is a shear wall on grid D starting at grid 5 that does not appear to have hold down indicated. Per the calculations this wall requires HDU5 hold downs. Please clarify.

F. Reference sheet S101a. It appears there are several conditions where steel columns are being using as hold downs. Please provide details showing how lateral loads are transferred to these steel columns. Details must be provided for overturning from walls as well as overturning from walls above.

G. Reference sheet S101a. On grid 5 near grid C, please ensure the ATS-1 hold down is indicate in the correct location. It appears to be located outside of the wall.

H. Reference sheets S602 and S603. Please provide design of all hold down anchors per ACI 318-08 Appendix D. Please ensure the ductile or non ductile yielding requirements of sections D.3.3.4 through D.3.3.6 is met. Please note that since post installed and cast in place options have been indicated that designs for both options must be provided.

I. Reference detail 1 on sheet S603. The embedment for two of the ATS systems appears to indicate 19'. This is likely supposed to be 19". Please revise. Please provide design of these anchors as requested in 9H.

10. GRAVITY AND WIND DESIGN

Reference the drawings and the calculations. Please provide the following:

A. Reference the calculations. It does not appear as if any design for uplift on the roofs has been provided. Please provide design of all roof framing elements for wind uplift. Please show that all hurricane ties, hangers and other fastening of roof framing members have sufficient capacity to transfer the required uplift forces. Please ensure there is a sufficient load path for the uplift forces to a point in the structure where there is sufficient dead load to resisting the uplift forces. Reference IBC sections 1604.9 and 1605 and the SDPWS section 4.3.6.4.4.

B. Reference details 1, 2 and 12 on sheet S511, and details 9 and 11 on sheet S512. Please provide substantiating data showing the connections shown in the referenced detail have sufficient capacity the transfer the required out-of-plane wind loads or indicate where in the calculations this design has been provided. Reference IBC section 1605.

C. Reference the calculations. It doesn't appear as if the design of the headers in the header schedule has been provided. Please provide. Design must include consideration of both gravity and uplift forces, and the headers must be designed as fully unbraced.

11. OTHER DESIGN ITEMS

Reference the drawings and calculations. Please provide the following:

A. Reference details 2 through 5 on sheet S522 and details 1 though 4 on sheet S523. Please provide design of the parapets and their connections. Parapets must be designed for the loads require by ASCE  7-05 section 6.5.12.4.4.

B. Reference page L-34 of the calculations. Please clarify what is being designed on page L-34 of the calculations. It appears to be drag/collectors on specific grids, but these elements are not clear on the drawings, and it's not even clear what level this calculation applies to.

C. Reference sheet S602. Please provide substantiating data showing the 1/2" plywood used on the roof has sufficient capacity to transfer the required loads in areas of drift.

D. Reference detail 6 on sheet S512. Please provide design of the splice shown in the referenced detail.

E. Reference detail 9 on sheet S513. Please provide design of the canopies over the doors at the ends of the corridor for the load combinations including wind uplift as required by IBC sections 1604.9 and 1605.

12. DRAWINGS

Reference the drawings. Please provide the following:

A. Reference sheets S101a and S101b. In several of the grade beam call out it indicates to slope the grade beam. Please indicate the maximum slope of the bottom of the grade beams to be 1:10 as permitted by IBC section 1809.3. Where the slope exceeds this stepped footings are required. Where step footings must be provided it is likely that grade beam action would not be permitted to be used in resisting the overturning forces from the shear walls above.

B. Reference sheet S101a. There is a footing on grid 8 between grids B and C that indicates a top of footing of 99'-4" however it has a pedestal shown on top of it like the footings that have a lower top of footing. Please verify that this footing is intended to have a pedestal.

C. Reference sheets S101a and S101b. Under "Marks and Symbols Legend" please define CP-x.

D. Reference sheet S101a. On a couple of grid lines (line 9.5 for example) it appears that there is a transition between a thickened slab to a foundation wall condition. Please provide a detail showing how this transition is to be constructed (it's not clear where the transition occurs but the footing just above grid A has a top of footing elevation of 99'-4" while the footing below the foundation wall just below grid B has a top of footing elevation of 96'-0").

E. Reference sheet S111a. On grid 6 near grid F there is a detail cut that references detail 2 on sheet S512. Please verify that this detail cut is correct.

F. Reference sheet S111a. There are several conditions where it appears that an HSS beam is being connected to the side of a column. It does not appear as if a detail has been provided showing this condition. It's possible the details just has not been cut on the plans, but it didn't appear as if a details as provided on sheets S521 through S523. There does appear to be a detail showing tube steel beams framing over the top of columns. Please provide.

G. Reference sheet S111a. Please provide top of steel elevations for all steel framing.

H. Reference sheets S111a. At the Porte-cochere on the plan north side of the building there are two detail cuts that reference detail 10 on sheet S522. Detail 10 on sheet S522 appears to show a roof pop up on the Porte-cochere that does not appear to be shown on the plan. Please clarify.

I. Reference sheet S121a. There is a detail cut on grid 6 near grid B that references detail 5 on sheet S511. It appears this should be 7 on sheet S511. Please revise.

J. Reference detail 8 on sheet S502. Please indicate the reinforcement requirements for the house keeping pads.

K. Reference sheets S111a and S111b. There are two canopies over the doors at the ends of the corridors. The detail references the Architectural drawings for dimensions. This information does not appear to be on the Architectural drawings. Please clarify.

L. Reference detail 7 on sheet S521. Please provide rotational restraint of the steel beam at the point of support as required by AISC 360-05 section 6.3.

M. Reference the roof framing details. Please clarify what type of hanger applies where. The hangers indicated in the schedule has different uplift capacities and it is possible the that only a specific hanger will have sufficient capacity to transfer the required uplift forces. See comment 10A.

N. Reference details 3 and 4 on sheet S522. The Simpson A34 clip indicated on the end o the brace back does not have a rated capacity to transfer upward forces. Please revise the details to include a connection that can transfer the required upward force from the brace back. Reference the 2015-2016 Simpson catalog. This also applies to detail 3 on sheet S513.

O. Reference detail 3 on sheet S601 of the drawings. Please revise note 1 of the schedule to indicate (3) #3 or (2) #4 ties in the top 5" of all pedestals as required by ACI 318-08 section 7.10.5.6.

P. Reference detail 4 on sheet S601. Please provide required development lengths for hooked reinforcement as well as a typical detail showing the required dimensions of hooks (radius, extension, etc). Reference IBC section 1901.4.

Q. Reference detail 6 on sheet S602. Please indicate the end length requirements for all strap hold downs.

13. SPECIAL INSPECTORS

Please provide a letter from the Owner indicating who they will be hiring to provide the special inspections on this project. The special inspectors must be licensed by MOA in the types of inspections to be performed. Reference IBC section 1703.1.

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.

All submittals should be sent to the permit manager.