第二大道地铁– Phase 1
New York City
Best Project, Transportation
Key Players
Project Owner/Developer:MTA-Capital Construction Co.（MTACC）
总承包商/建筑经理：WSP Parsons Brinkerhoff
领导设计公司：AECOM-ARUP合资企业（AAJV）
Geotechnical Engineering:GZA GeoEnvironmental
Lighting Design:Domingo Gonzalez Associates
A $4.45-billion, nearly decade-long effort to build the first major expansion of New York City’s subway system in 50 years was bound to have surprises along the way, but few were as showstopping as a stretch of fractured rock below the intersection of Second Avenue and 91st Street. The first phase of the Second Avenue Subway, which runs 1.8 miles on Manhattan’s East Side, already promised huge tasks of building three new stations below 72nd, 86th and 96th streets; upgrading a station at 63rd Street and connecting to a tunnel built decades ago in East Harlem; and tackling that work in a crowded mix of massive high-rise and aging low-rise buildings.
The project that extends the Q Line north and now serves 176,000 passengers daily—greatly reducing congestion on the transit system’s only other Upper East Side service on Lexington Avenue—also has set a new bar for station design that optimizes rider experiences and uses modern technology.
但是要到达那里，有很多岩石要雕刻，要拆除的泥土，支持地基以及在那个棘手的十字路口的条件下 - 冻结。Despite multiple boring tests, the project team found a patch of softer soil and unstable rock at the eastern tunnel’s planned mouth late in planning because it was right under the 91st Street-Second Avenue intersection, and it threatened to hold up progress of the tunnel boring machine (TBM) needed to cut caverns for the two new stations further south.
S3隧道连接器 - 美国Skanska，Schiavone和J.F. Shea Construction的联盟，提出了首先钻探西方隧道的备用计划，然后在东隧道区域使用地面冰点技术，该技术可以使土壤足够稳定在土壤中TBM在该区域井井有条。这项工作发生于2011年，还需要缩短该合同中西隧道的长度，并将其转移到单独的采矿阶段，以便保持按时。The technique, which entailed drilling small pipes into the ground and circulating chilled brine through them to freeze the soil enough to behave like rock, had worked for Skanska on the 7 Line subway extension project on Manhattan’s West Side, and it did the trick on Second Avenue.
“We had to decide what to do on the spot,” says Chu Ho, chief geotechnical engineer on the project at Arup, which in a joint venture with AECOM led all engineering and architectural design services.
这样导致了projec可能是快速解决方案t’s most notable achievement of all—hitting its fiscal and schedule targets, says Craig Covil, Arup principal. After breaking ground in 2007, the Metropolitan Transportation Authority set a goal in 2009 to open the new line in December 2016, and made it with a free preview for dignitaries on New Year’s Eve.
他说：“明确的亮点是按时和预算开放。”“税收服务从1月1日上午开始。”
大规模合作伙伴关系
MTA as project owner was conductor of an orchestra of contractors and consultants, with big partnerships in star roles. Those involved Arup and AECOM on design and structural, civil, geotechnical and MEP engineering; contractor teams including S3, other Skanska ventures with Traylor Brothers and with L.K. Comstock; an E.E. Cruz- Tully Construction joint venture, among others; and WSP Parsons Brinkerhoff, now WSP, as construction manager.
The design side had 32 subconsultants, says Chris Bennett, AECOM chief engineer in the New York region. “At the peak of design, we had 350 people on the project.” It worked smoothly on the design front, says Richard Potter, the project’s chief MEP engineer at Arup for 15 years. “We were able to integrate teams from various companies,” he says. “No one was trying to push corporate agendas.” The same ethic bolstered the construction side, according to Brian Hotchkiss, AECOM project architect on later phases. “Getting all the trades working together, seeing it all on the same page, was a big thing.,” he says.
“Getting all the trades working together, seeing it all on the same page, was a big thing.”
– Brian Hotchkiss, AECOM
Such coordination was critical on a project conceived in the 1920s but not started until 50 years later. After completing several sections of tunnel, city officials facing the mid-1970s budget crisis abandoned the project. Today’s incarnation may one day run 8.5 miles down the East Side if the MTA proceeds with all planned phases, a concept mapped out by the design joint venture, says Bennett. “Phase 2 will take it up to 125th Street,” he says.
当然，有很多颠簸的时刻。2009年，官员们下令在检查员发现立面裂缝时撤离在第93街的六层步行建筑。三年后，一对受控的爆炸出现了，其中一对岩石和碎屑沿着街道和建筑窗户散发出来，尽管没有造成伤害。在2013年大雨之后，城市消防员还必须营救一个被困在第96街的泥土底部的沙霍格。
但是该项目在1500万工人小时内的安全记录（美国职业安全与健康管理局的记录事件率为2.8，时间损失1.38）低于行业标准，没有死亡。
High Expectations Deep Underground
在十年的建筑和将近二十年的设计中，有两个亮点脱颖而出：复杂的，肌肉发达的努力，打破，钻孔，切割和排干元素，以雕刻新的隧道以及精心制作的精巧工作，以创建均引起公众的震撼力墙壁后面的公用事业和系统的空间和错综复杂的难题。
The digging involved boring, excavation, blasting, cut-and-cover and other methods to create 2.65 miles of tunnels and station caverns, including the 800-ft-long TBM launch box that would later become the 96th Street station. The TBM cut 12,800 ft of twin-track, 22-ft-1-in.-dia tunnels and stations that are up to 64 ft wide, 1,600-ft long and 100 ft deep.
The team encountered a stew of geologic conditions. “We ran into hard rock—Manhattan schist—glacial deposits, soft soils, underground water,” says Arup’s Ho.
这一切都是在一个拥挤的城市,挤满了utility lines and building foundations of every size and condition, says Richard Giffen, Arup’s chief structural engineer on the project. “We had to modify and protect these buildings, and each station required major modifications,” he says. “Thirty-story buildings have columns that drop down into the project.”
The team undertook great efforts to establish tolerances, measure structural movement, shore foundations, create retention systems, stabilize ground, remove muck and manage water conditions and other stresses, Ho says.
The effort also played matchmaker—connecting south to the 63rd Street Station, which needed a near-complete upgrade, and to already built tunnels to the north, which are at higher elevation than the new alignment, Giffen says. “These were complicated sequences of tying into the existing structures and supports … and in some cases demolishing and rebuilding,” he adds.
Each station was its own epic, requiring a modern battery of ventilation, track, signal, lighting, power and communications systems, along with high standards for air temperature management, passenger navigability and visual appeal through design and artistic finishes.
In order to open column-free spaces for passenger flow, the team had to fit a complex array of mechanical, electrical, drainage and other support systems in tight spaces behind station walls, says Jim Collins, station design manager and coordinator at AECOM. “They didn’t want to use extra cubic yards there,” he says. “At the start, we were designing it all in [two dimensions] because [building information modeling] systems were in their infancy.”
A final payoff is in new station design guidelines for MTA evolving from the final production documents, which are meant to be a flexible, lasting legacy of the Second Avenue undertaking, according to Ken Griffin, AECOM’s chief architect who was on the job in its early days. “We helped them build a road map for what should be in a modern station,” he says.
It captured the project’s merging of old and future, says Don Phillips, a deputy project manager at Arup in the early going. “The subway was 100 years old, but we had to make this a 21st-century, even 22nd-century system.”
