20140813091600462.pdfENGINEERNNG
July 14, 2014
Jeanie McConnell
City of Edmonds
121 5th Avenue North
Edmonds, WAV803O-3l45
RE: Permit: 2014{457
Project Name: Prestige Care
Detention Vault Review
Dear Ms. McConnell,
itemized below bour response tothe detention vault plan review comments submitted
on June 18, 2014 for the above referenced project. Our response appears in bold.
SVI.1
1. Add "ACI 350-06 Code Requirements for Environmental Engineering Concrete Structures
(ACI 350-06)". This code governs the design of environmental engineering structures
including detention vaults.
Vault has been redesigned to ACI 350-06. Please refer torevised drawings and
additional calculations.
2. 250 PSF per geotechnical memorandum, Update here in calculations.
The 250psf live load surcharge is a vertical load. Page 15 of the geotechnical report
states "For traffic loads, we recommend using an equivalent two foot soil surcharge, of
about 250 psf". A 2ft surcharge of 50pcf soil was added resulting in a lateral load of
3. Recommend defining maximum distance between construction joints rather than a plan
are. Also, ACI 350 minimum shrinkage and temperature reinforcement requirements
Table 7.l2.21are based off length between movement joints.
Control joint note revised to 20ft maximum. Refer to revised notes sheet.
SV2.1
1. Recommend providing vault elevation. Also nolid elevations provided.
Lid elevations added to2/SV2.1. Top of slab elevations are included mn I/SV2.1. ImKet
Prestige Care -13073.10 July 14, 2014
Detention Vault Comment Response Page 2 of 3
SV3.1
1. Provide hydrophyllic water stop as this joint will crack.
Waterstops have been provided at cold joints.
2. No interface shear calculation included. Will probably have sufficient interface shear capacity but may not
meet minimum interface shear reinforcement requirements.
Interface shear adequate. Refer to the attached interface shear calculation.
3. Check minimum reinforcement requirement in ACI 350-06 Table 7.12.2.1 and minimum cover
requirements in ACI 350-06-7.7.1. Both of these requirements are more stringent that ACI 318 to reduce
cracking in the structure. This applies to both walls and footing.
Wall design revised per ACI 350. Refer to the attached reinforcement calculations.
4. Reinforcement is not fully developed her. Typical in multiple locations. Also, insufficient reinforcement to
resist diagonal shear crack.
Development length has been calculated and the reinforcement has been revised to include a hook.
Top reinforcement has also been provided to resist shear crack.
S. Strongly recommend a double mat of steel in walls, This is desirable for walls and slabs in a detention
vault to prevent cracking and remain water tight (especially in this case where walls/slab are 8" thick or
more).
Vault has been redesigned to ACI 350 which does not require 2 layers of reinforcement for walls 10" or
less. Vault walls have been updated for requirements of ACI 350. Refer to the attached calculations
and revised details.
6. Wall - Examine case of water in vault with loss of backfill. Will cause tension on outside of the wall and
may require another mat of steel.
Wall has been analyzed per load combinations in ACI 350. In the load case where the vault is full of
water the resisting soil has been reduced to 0.611-11 per the ACI 350 9.2.1 (d). A load case where the vault
is full and the soil is not present is not required by code.
7. Slab- Examine case of empty vault where self weight of vault above slab, fill above vault, and live load will
cause tension in top of slab. May require an additional mat
Additional reinforcement added to footing. Refer to revised details.
250 4th Ave S Edmonds, WA 98020
p. 425.778.8500 f. 425.778.5536
IUC5INRIhIG
Prestige Care 1]07]10
Detention Vault Comment Response
Calculations
Page
July 14,014
Page 3of3
The 25Opoflive load surcharge ismvertical load. Page 16ofthe geotechnical report states "For traffic
loads, werecommend using anequivalent two foot soil surcharge ofabout 25011 A2ftsurcharge of
SOpdsoil was added resulting |nalateral load of1ODpsf.
Page
An additional load case has been provided with water at the exterior and no water inside the vault. The
water pressure was applied below the elevation cfthe footing drains. Nuwater pressure was applied
above the footing drains. Per the civil plans the footing drain will 6e1G"above the top ofslab. Water
pressure was added tothe wall for the bottom 1O". This load case does not govern the design o;the
interface shear adequate. Refer tnthe attached interface shear calculation.
Vault slab thickness and reinforcement has been increased. Refer tmattached buoyancy calculation.
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10
if you have any questions or comments regarding the responses to this review please do not hesitate to call.
Sincerely,
CG Engineering
Dennis Titus, PE, 5E
250 4'h meS[�on�wm�o�
°�m�� ~�==�p. 425778o500 f. 425,778.5536