3315 SEAWAY BLVD 2020-06-05 - Laserfiche WebLink

z i 1111111111011111 filters that weigh about 1,600 pounds each. Distributing that loads as a percentage of the 125 PSF loading is actually only about 1%of the 125 PSF.So the current design is conservative for the intended loading. d. Continuing with the previous comment,the design loads on Sheet 51.0 shall clearly distinguish the design loads for storage and permanent equipment. DCI Response:There is currently no intent for the ceiling of the TAT space to be used for storage. Sheet S2.1 shows the(3)three intended HEPA filter units on the TAT ceiling pan. e. The tributary wall mass to the structural lid only include the longitudinal walls. The mass should be increased to include the transverse walls. Note that a weight estimate of wall Types 2 and 12 per Sheet A8 appears to exceed 10 psf. Architect to verify that Wall Type 12 should include GWB on both sides similar to other wall types. DCI Response:The total dead load assigned to the ceiling of the TAT space as seismic mass is 23 PSF.The dead load of the ceiling is calculated as 13.4 PSF.This leaves 9.6 PSF to allow for the tributary mass of the walls below.This more than adequate for the walls that exist below the TAT ceiling.Also,it is our understanding that wall type 12 has drywall on one side and plywood on the other side.Even if drywall were to be added over the sheathing the weight of the wall would be 9.9 PSF.The weight summary of the wall is 2.8 PSF for 2x10 studs @ 16"o.c.,2.8 PSF for each layer of 5/8 GWB and 1.5 PSF for'A"sheathing.See calculations sheet S-1. f. It is not clear if the 125 psf load represents both permanent equipment and storage loads. Where either load is not equally distributed across the structural lid,the weights shall be effectively loaded to the wall lines support the associated lateral seismic load. Non-uniformly distributed loads shall not be uniformly distributed to all wall lines. DCI Response:The ceiling of the TAT space will only have 3 HEPA filters.The contact load to the ceiling framing is about 31 PSF which is much less than the 125 PSF design load.The lateral system has been overdesigned using 25%of 125 PSF as the seismic mass attributed to the mechanical equipment. g. The limited wall length on Grid 4.4 is only 7 feet long,not 9'-10" per page T-6. DCI Response:The shear walls on grid 4.4 have been redesigned using the updated wall lengths. Which are now 7'-0", 19'-10"and 23'-3".See supplementary calculations sheets S-2 thru S-4. h. Page T-6 includes a 4'tributary roof width resisting overturning for the walls on Grids 4.4 and 3. Based on the joist spacing of 16" per Sheet 52.1,the tributary width is only 8". The resisting weight shall be reduced. DCI Response:A 4'tributary floor or ceiling width when framing is parallel to the shear wall has been used to calculate the associated dead load effective in resisting shear wall uplift.This 4'