Tunnel responses to Bureau of Sewers comments, Dec 1987

NYC 9/11 Public Portal Document

• 11th Avenue.

Invert at 33rd street at west of 33rd street.

. Satisfy all the house connections along 33 & 34th streets not to be flooded.

. Hydraulic gradient satisfies the MH cover elevation.

At this point, this request cannot be met for the following reasons:

Will change the siphon cross sections (reduced)

. Will force to lower the profile. This cannot be done because of the controlling Inverts at MH #1, #2, & #3.

It will increase the velocity which will raise the hydraulic gradient.

. It will cause flooding at critical house connections and MHs. The proposed cross section and design was reviewed by BOS* staff in several different meetings.

15. a) Will do drawings. S-33, 34, 35, and 36.

b) Guide lines for design of chambers is attached to Hydraulic calculations. The selected radius satisfies all of the reguirements. See calculations which are stamped by a P.E.

16. a) Standard practice of R bar detailing with proper dowels are shown.

b) All necessary Information and relevant details and bar placements are shown on Dwgs. S-93 and 94.

c) Plow Redirection Chamber is very close to the adjacent Plow Distribution Chamber and new chamber (MH) #3 from where access can be provided.

17. a) Dwgs S-33 thru S-36 have more details (sections a plans) than the sample given. There are 26 sections taken to cover 180 feet long siphon which should be adaguate.

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