C Community Board Eight Community Board Eight C it B it B d - PowerPoint PPT Presentation

1 SECOND AVENUE SUBWAY PROJECT C Community Board Eight Community Board Eight C it B it B d Ei ht d Ei ht Second Avenue Subw ay Task Force Second Avenue Subw ay Task Force June 17th 2008 June 17th 2008 June 17th , 2008 June 17th , 2008 June 17th, 2008

2 Proposed Revisions to Track Alignment PHASE 1 PHASE 1 June 17th, 2008

3 BACKGROUND BACKGROUND � Station Designs in Final Design Phase • 86 th Street - 2 track station cavern (one platform) 86 th St t 2 t k t ti ( l tf ) • 72 nd Street - 3 track station cavern (two platforms) � Decision made to change alignment • Lower station track levels • Reduce number of tracks and platforms at 72nd Street Reduce number of tracks and platforms at 72nd Street • Reduce construction cost and risk � New proposal for Station Designs (June 08) � New proposal for Station Designs (June 08) • 86th Street - 2 track station cavern (one platform) • 72nd Street - 2 track station cavern (one platform) June 17th, 2008

4 THREE TRACK TO TWO TRACK THREE TRACK TO TWO TRACK Three Track alignment plan g p June 17th, 2008

5 THREE TRACK TO TWO TRACK THREE TRACK TO TWO TRACK Two Track alignment plan June 17th, 2008

6 THREE TRACK TO TWO TRACK THREE TRACK TO TWO TRACK 2 nd Ave June 17th, 2008 100ft 70ft North

7 June 17th, 2008

8 BENEFITS/IMPACTS BENEFITS/IMPACTS � Benefits • Reduction in construction cost • Reduction in excavated material and truck trips • Reduction in temporary deep subsurface easements in • Reduction in temporary deep subsurface easements in 72 nd Street area � Impacts I t • N ew deep subsurface easements required in 63 rd Street area June 17th, 2008

9 NEXT STEPS NEXT STEPS � Environmental review E i t l i � Review design opportunities created by narrow er cavern at 72nd Street � Commence Real Estate Acquisition process for modified subsurface easements difi d b f t June 17th, 2008

10 Maintenance and Protection of Traffic PHASE 1 PHASE 1 June 17th, 2008 (MPT) ) (

96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION Existing Tunnels 96 th Street Lexington Ave / Lexington Ave / Contract 2 Contract 2 63 rd Street Contract 1 • Award: 4 th Quarter 2008 June 17th, 2008 11

96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION Entrance 1 Elevator Entrance 3 Ancillary 2 y 2 nd Avenue 2 nd Avenue 92nd 93rd 94th 95th 96th 97th Ancillary 1 Entrance 2 June 17th, 2008 12

96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION 96 TH STREET STATION Street Grade Street Grade 7’ to 8’ Utility Zone 7’ to 8’ Utility Zone (48’ ‐ 0”) (28’ ‐ 4”) ‐ 0”) (48’ ‐ (28’ ‐ 4”) (65’ ‐ 0”) June 17th, 2008 13

14 SCOPE OF WORK SCOPE OF WORK SCOPE OF WORK SCOPE OF WORK � Utility Relocation between 95th Street and 99th Street y � Slurry Walls & Decking between 95th street and 99th Street 99th Street � Excavation between 95th Street and 99th Street � SOE Walls and Excavation for Entrances & Ancillaries � Construction of 96th Street Station Base Slab from 92nd Street to 99th Street June 17th, 2008

15 MPT PLAN DEVELOPMENT MPT PLAN DEVELOPMENT CRITICAL ISSUES DURING MPT PLAN DEVELOPMENT � Interface with Ongoing TBM Launch Box Contract 26002 � Construction staging is developed to maintain two block buffer � Maintain Access to Metropolitan Hospital � Temporary closure of Side Streets to Build Walls for Entrances and Ancillaries � Maintenance of Left turn operation at 96 th /97 th Street � Maintain 5 lanes of traffic on 96 th St. when work is being done at 97 th St. � Maintain 3 lanes of traffic on 97 th St. when work is being done at 96 th St. � Maintain 4 lanes of traffic on Second Avenue � Maintain 7’ sidewalks June 17th, 2008

16 MPT PLAN MPT PLAN MPT PLAN MPT PLAN West Side Utility Relocation 92 nd Street 93 rd Street 94 th Street 95 th Street 96 th Street 97 th Street Walkway SECOND AVE 91 st Street C-26005 Work Zone (95 th Street to 99 th Street) Present Contract (91 st Street to 95 th Street)

17 MPT PLAN MPT PLAN MPT PLAN MPT PLAN West Side Slurry Wall Installation, Decking & Excavation 92 nd Street 93 rd Street 94 th Street 95 th Street 96 th Street 97 th Street Walkway SECOND AVE 91 st Street C-26005 Work Zone (95 th Street to 99 th Street) Present Contract (91 st Street to 95 th Street)

18 MPT PLAN MPT PLAN MPT PLAN MPT PLAN East Side Slurry Wall Installation, Decking & Excavation 92 nd Street 93 rd Street 94 th Street 95 th Street 96 th Street 97 th Street Walkway SECOND AVE 91 st Street C-26005 Work Zone (95 th Street to 99 th Street) Present Contract (91 st Street to 95 th Street)

19 MITIGATIONS MITIGATIONS MITIGATIONS MITIGATIONS � Additional Variable Message Signs � Additional CCTVs � Additional Traffic Agents � Signal Timing Modifications at 2nd Avenue /96th St., Third Avenue / 96th St., First Avenue/ 97th St., 2nd Avenue/ 97th St. � Extend right turn restriction time period at First Avenue onto 96th St. EB to start at 1pm to 7pm from current 4pm to 7pm � Improvements in traffic operations at 96th St. and 97th St near FDR Drive � Monitoring of construction zones via NYCDOT TMC at Long Island City June 17th, 2008

20 69 th STREET & 72nd STREET SHAFTS PHASE 1 PHASE 1 June 17th, 2008

69th Street Work Shaft Existing 20’ 4 Traffic 4 Traffic sidewalk curb line sidewalk curb line Lanes Work Zone (Typical) Alternative Delivery Zone (Typical) (Typical) 6/18/2008 21

72nd Street Work Shaft Existing 20’ 4 Traffic 4 Traffic sidewalk curb line sidewalk curb line Lanes Work Zone (Typical) yp Alternative Delivery Zone (Typical) (Typical) 6/18/2008 22

69th & 72nd Street Construction Shafts Shafts will be used by Shafts will be used by Contractors to excavate the station cavern & muck removal 6/18/2008 23

24 SIDEWALK ENCROACHMENTS SIDEWALK ENCROACHMENTS SIDEWALK ENCROACHMENTS SIDEWALK ENCROACHMENTS � Vaults, Cellar doors, Utility vaults, etc � Sidewalk Cafes � Canopies and Awnings � Sidewalk retail areas � Public telephones, Bike racks etc � Steps, Ramps, Oil fill valves June 17th, 2008

Second Avenue Subway Second Avenue Subway Construction Progress Construction Progress Update (March to June) Update (March to June) Update (March to June) Update (March to June) Presented by Presented by Presented by Presented by S3 Tunnel Constructors S3 Tunnel Constructors June 1 7 , 2 0 0 8 June 1 7 , 2 0 0 8 6/ 18/ 2008 6/ 18/ 2008 1 1

Topics Covered Topics Covered • Progress update (March to June) P d t (M h t J ) • Secant Pile Walls • Slurry wall equipment and steps Slurry wall equipment and steps 6/18/2008 6/18/2008 Page 2

“Gas Trench” + splice boxes Gas Trench + splice boxes Splice Box Box Gas 2 nd Avenue Looking North Future 2 nd Avenue Subway 6/18/2008 6/18/2008 Page 3

6/18/2008 6/18/2008 Page 4 Excavation for Gas Trench March 2008 View of

6/18/2008 6/18/2008 Page 5 Install Sheeting for Gas Trench View of April 2008 2008

6/18/2008 6/18/2008 Page 6 Install Gas Pipe in Trench View of May 2008

6/18/2008 6/18/2008 Page 7 30” Gas Main Inside 42” Carrier Pipe

Place Splice Boxes For Deck Beams & Backfill 6/18/2008 6/18/2008 Page 8

“Sew er Trench” + other utilities Sew er Trench + other utilities Splice Box Box Sewer Sewer Gas 2 nd Avenue Looking North Support Support Future 2 nd Avenue Subway 6/18/2008 6/18/2008 Page 9

6/18/2008 6/18/2008 Page 10 Installed Mini Piles at 92 nd to 93 rd Str.

Construction of Drilled Shafts- 93 rd to 95 th Str. 6/18/2008 6/18/2008 Page 11

6/18/2008 6/18/2008 Page 12 Pour Concrete for Drilled Shafts

6/18/2008 6/18/2008 Page 13 Construct Sew er in Trench

Secant Wall at selected location location Splice Box Box Sewer Sewer Gas 2 nd Avenue Looking North Secant Wall Support Support Future 2 nd Avenue Subway 6/18/2008 6/18/2008 Page 14

Topics Covered Topics Covered • Progress update (March to June) P d t (M h t J ) • Secant Pile Walls • Slurry wall equipment and steps Slurry wall equipment and steps 6/18/2008 6/18/2008 Page 15

6/18/2008 Location for Secant w alls SECANT WALL Portions installed

Secant Pile Wall Construction- 91 st to 92 nd Str 6/18/2008 6/18/2008 Page 17

Secant Pile Wall Construction- 91 st to 92 nd Str 6/18/2008 6/18/2008 Page 18

Secant Pile Wall Construction- 91 st to 92 nd Str 6/18/2008 6/18/2008 Page 19

Secant Pile Wall Construction- 91 st to 92 nd Str 6/18/2008 6/18/2008 Page 20

Topics Covered Topics Covered • Progress update (March to June) P d t (M h t J ) • Secant Pile Walls • Slurry wall equipment and steps 6/18/2008 6/18/2008 Page 21

6/18/2008 6/18/2008 Page 22 Location for Slurry w alls SLURRY WALL y

6/18/2008 2 nd Avenue Looking North Future 2 nd Avenue Subway Slurry Wall Slurry Walls Work Building Building

Slurry Wall Excavation Stage1 in Steps Primary Panel Excavation Clamshell Bucket 6/18/2008 6/18/2008 Stage1 Page 24