Shani Wallis, Editor

Main Manhattan elements

Dragados/Judlau JV will construct all Manhattan underground works associated with East Side Access project. A negotiated contract of $734 million adds excavation of the two large stations caverns and all their associated works to the JV's $428 million TBM running tunnels contract under Park Avenue for the Long Island Rail Road (LIRR) services into Grand Central Terminal. The 1,500ft long x 67ft high x 58ft 6in span (457m x 20m x 17.86m) caverns will accommodate eight platforms, two above two, in two caverns. Nine deep elevator and escalator shafts will provide access to the surface through the Terminal's famous great hall.

Confirmation of the caverns contract in February brings the JV's work in Manhattan for the project to more than $1.15 billion.

The JV is preparing a bid also for the soft ground tunnels to connect the Manhattan alignment to existing LIRR lines on the other side of the East River in Queens. A bid opening date for this often postponed design-bid-build contract is rescheduled for this summer. The estimated $400 million contract is for two TBMs to drive four tunnels under multiple rail tracks in the Sunnyside Yard rail depot and junction.

Lead project designer for project owner the MTA is Parsons Brinckerhoff.

Plan of the project's alignment

Meanwhile, the two TBMs boring their way beneath Park Avenue toward Grand Central Terminal for the JV are more than half way through their initial 7,000ft (2km) long drives. On Thursday this week, (June 5), the Seli TBM had advanced 5,015ft since starting in September 2007 and is advancing through the alignment's station cavern zone. The Robbins TBM is 3,513ft into in the parallel drive after starting in January 2008 and had just passed under the 53st Subway tunnels.

Detail of the Queens tunnels

Ground conditions for the leading Seli machine were said to be very good and becoming harder with penetration rates down a bit to about 5ft/hr. The Robbins machine is just completing a reach of installing full-round steel sets on 5ft centers to pass safely under the 53rd St Subway tunnels with a clearance of about 12ft. Full sets were needed also to pass through a zone of decomposed granite on the outside wall of the tunnel. Shotcrete provided strength for the gripper.

With excavation of the caverns in hand, the JV has optimized the construction plan and will now bore four TBM tunnels through each station cavern. At the end of these first drives we will bring both TBMs back to the GTC 3 wye excavations on the upper alignment and bore two more parallel tunnels through the cavern zone. The machines then go back to GCT 5 wye to bore the lower two running tunnels and we will again bore a second two station cavern tunnels at that elevation. The rock is said to be good and the distance between parallel drives is 14.5ft or more so there is no concern for the strength of the pillars between and the eight cavern bores that will give the JV a big advantage for the top heading and bench excavations of the deep caverns.

NAT conference reference:
East Side Access - Segmental lining design challenges for closely spaced and shallow tunnels and Tuesday, June 10, 8.30am - Track II

Schiavone and Dragados make a team

Acquisition of Schiavone Construction by Dragados in December 2007 is set to contribute to the success of the East Side Access contracts. Dragados bought 100% of the previously privately owned New Jersey-based company and its extensive New York City experience for a reported $150 million. Schiavone is busy on New York City's other major MTA transit projects working in joint venture with Skanska and Shea on the first $337 million contract for the 2nd Avenue Subway project and with the same partners on the $1.145 billion negotiated contract for the No 7 Line extension of the Subway from Time Square under 41st St and 11 Ave to 34th St. It is working by itself on the South Ferry rebuild projects in Lower Manhattan. In joint venture with Shea and Frontier Kemper and for a total of more than $1 billion, it is completing more than 45,000ft (13.7km) of tunnel excavation and concrete lining for Water Tunnel No 3 for the Department of Environmental Protection. Previously it completed the award winning excavation of new concert facilities under the existing Carnegie Hall.

NAT conference reference:
Design of large and shallow caverns for New York Second Avenue Subway
Tuesday, June 10, 8.30am - Track II

Footnote:

Phone calls concerning charges of possible connections with organized crime brought against the company's senior projects manager Anthony Delvescovo were not returned. According to reports in ENR, Delvescovo's arrest was part of a federal sweep that charged 62 individuals with alleged crimes ranging from loan-sharking to embezzlement.