Thanks to a box-jacking method new to the U.S., a contractor “ambassador” program and flexibility allowed by design-build, the New York Metropolitan Transportation Authority (MTA) is well underway with a $2.6-billion, 10-mile project to add a third track to the Long Island Rail Road (LIRR) commuter line.

Running from Floral Park, N.Y. to Hicksville, N.Y., the effort constitutes one of the region’s most significant transportation infrastructure projects. Major project elements include elimination of eight grade crossings, new parking facilities, upgrades to railroad infrastructure and improvements to stations.

Before the COVID-19 pandemic hit, the stretch of railway served about 100,000 commuters a day, running 250 trains, says Thomas McGuinness, MTA deputy project manager for the main line expansion. With only two current tracks, “during peak flow, you assume one [flow of traffic] in each direction,” he says. “We have peak flow schedules set up that utilize both tracks in peak flow directions for short periods of time. But it hampers reverse commutes.”

The future third track will accommodate those reverse commutesh, McGuinness says. “We will increase capacity by 50%,” he says. The third track also will allow for increased flexibility around maintenance issues that might pop up, he adds.

Dragados USA，John P. Picone，Halmar International和CCA Civil的第3轨构造仪（3TC）的工作包括更换通信，信号，轨道工作，交换机，交换机，变电站和电源。官员们说，3TC持有一份17亿美元的设计建设合同，并计划完成2022年底的完整日期。尽管大流行，但该时间表仍行驶。

Two grade crossings have been eliminated, says McGuinness. Crews are also replacing or rehabilitating seven bridges, ensuring that their clearances are at least 14 ft. Five stations are being upgraded or rebuilt. “There will be more platform space, more overhead canopies, Wi-Fi, communications—a real focus on an aesthetic upgrade,” says Susan Walter, executive vice president of Stantec, lead designer on the 3TC team. Stations will also receive security enhancements such as cameras and bollards and will be compliant with the Americans with Disability Act.

Work is almost complete on a new five-level, 551-space parking garage at Mineola Station, replacing the surface parking area. The garage, which consists of 600 precast concrete sections, will be completed this fall.

Walter says the main challenge lies in “just the size and volume of work associated with this project and being able to coordinate the design with all of our partners. We’re all in lockstep moving forward. It’s a lot easier in the pursuit phase. Now we’re really working on the day-to-day details. Like any project, it takes laser-focus communication between the parties to really move the design from the concept to the final design.”

由于灵活性和communication, the contractor was able to choose a box-jacking system from Italian firm Petrucco that allows for new underpasses to be placed over a weekend, rather than causing weeks of disruption.

Jacked Up

Petrucco的系统中,在美国,从未使用utilizes hydraulic jacks and spreaders to move a cast-in-place concrete box carrying the entire underpass and rail bridge into place in a matter of hours. “It’s accelerated bridge construction,” says McGuinness. “You construct a new bridge superstructure and substructure, almost like a culvert U-structure. [Crews] set the steel superstructure on top and remove the sheeting supporting the railroad.” Hydraulic jacks then push the structure into place.

此方法需要关闭当地街道约180天。麦吉尼斯说：“过去，类似的项目是独立的，可能18luck官网需要一年的计划和一到两年的时间才能完成。”“在这里，它们被整合到一份合同中；一个赛季，我们完成了三座桥梁和两个年级的过境点。”

The first installation, at Urban Avenue in Westbury, N.Y., was performed on July 20, 2019. The second installation, on Covert Avenue in New Hyde Park, N.Y. on Aug. 24, went even smoother as crews got accustomed to the method.

The Covert Avenue box consists of a 112-ft by 40-ft reinforced concrete slab, with 24-ft side walls and two spans on top bearing rail and a roadway. Crews cast the 2,000-tonne concrete box on site, and then slid it 58 ft into place.

将盒子从混凝土发射板上推开，但该板并没有延长其将行驶的整个距离。在Covert Avenue地点，该盒子的最终位置在平板上为一半，在土壤上的一半。在较早的Urban Avenue地点，该盒子的最终位置完全在土壤上。

According to Petrucco, the company has performed rail underpass box-jackings some 1,500 times globally, including in Spain, Canada and Qatar, since the method was first introduced in 1978.

Work is underway to eliminate the next grade crossing, at New Hyde Park Road. The project began with utility relocation last spring and demolition of the road. Crews began drilling soldier piles in September to shore up the excavation area. Excavation began in February, with a planned seven-month road closure.

During a weekend double-track outage planned for July 11-12, the existing tracks and systems will be removed to allow for excavation under the shored-up tracks. Then the bridge will be pushed into place with 20 hydraulic jacks, each with a capacity of 250 tons for a total of 5,00 tons of jacking force. The jacking system is capable of pushing the bridge 20 in. with each stroke. After each push, it must be reset. Over the course of the weekend, the jacking system will be reset 30 times to move the bridge 50 ft into its final position.

麦吉尼斯说，LIRR已经有一个多世纪的历史了，“大多数城镇和村庄都建立在周围”。“因此，您有很多本地企业。您的起重机正在贯穿地区。没有太多空间。”船员正在铁路通行权中登台和存储设备。施工活动通常仅发生距住宅的脚。

3TC项目主管Alan Paskoff说：“它长10英里，对于每个工作元素，您都有一定程度的发言权。”“在某些地方，您的一侧是通行权的一侧，另一侧有一个社区。村庄，县，城镇 - 具有不同规则和需求的众多人。3TC带来的一件事是一个强大的外展计划。我们习惯于在城市地区工作，因此来到郊区是一个不同的挑战。我们实际上是在人们的后院。”

传播商誉

To reduce impacts and increase goodwill, 3TC and the MTA established an extensive outreach program.

“Local ambassadors are assigned to each municipality,” explains McGuinness. “We hold monthly meetings with local officials. We have commitments to reduce noise levels. We measure air quality, vibrations, noise.” Mitigation measures have included sound curtains, soundwalls and temporary fencing.When 3TC did the first grade crossing, it set up an ice cream truck handing out free treats and rebuilt two Little League fields used for construction, says Paskoff. The team even has been building its brand. “We have a couple of street sweepers out there,” he says. “One of the mayors recommended that we put our name on the side of them.”

There is a community center dedicated to providing information about the project, although at press time it was closed. Paskoff says 3TC’s appointed ambassadors have attended meetings of chambers of commerce and historical societies, among others. “We know the building owners and business owners,” Paskoff says.

由此产生的善意是项目成功的关键。Paskoff说：“我们在不同的位置24/7全天候工作，有时是夜间和周末。”他回忆说，当工作人员在樱桃巷建造了一座新桥时，“几乎在区域中间的角落里有一个女人，给她的花朵浇水并看着工作。”

Moreover, “sometimes we have to move people out of their homes for a weekend because of the noise,” Paskoff adds. “They understand what’s going to happen. We’ve had to take parking lots sometimes from business owners. [They realize that the] more they help us, the quicker we get out of their neighborhoods.”

Based on survey feedback from municipalities, 3TC can receive incentives of up to $250,000 per quarter, says McGuinness. “We distribute scorecards to local residents and municipalities about the contractor’s performance in maintaining commitments to communities,” he notes. “The scores drive how much of that incentive the contractor receives.” 3TC has been scoring well; it earned $183,000 last quarter, which is about typical, McGuiness adds.

Collaboration

Thanks to contractor input early on, the new third track will run mostly on the south side of the existing two tracks beginning at the Floral Park station. “It stays on the south through the entire corridor through Westbury,” McGuinness points out. “East of Westbury, it adjusts to the north side.” Moving parts of the new track to the south simplified some construction phasing, he notes.

McGuiness says while the project is under one contract, “it’s broken down into 50 elements. Each element is a stand-alone project. Eliminating a grade crossing is one project. Replacing a station is another. What’s challenging is that your schedule is not linear. There’s no clear path to follow in the logic of a CPM [critical path method] schedule.”

与多个设计合作伙伴（包括MBE/WBE/资深公司拥有的公司）合作增加了许多移动作品的复杂性。Stantec的Walter说：“另一层是添加在设计的每个阶段进行连续的可构造性评论的需求。”她补充说，设计师必须与通行权团队，土木工程师，结构工程师和景观设计师接触。

The moving parts of 50 elements are put into six “buckets,” says McGuinness. “The managers of those buckets are like project managers themselves. On a higher level, senior management ensures coordination of those buckets.”

Another challenge is that essentially a whole new railroad is being built while the existing one keeps running. “New signals, utilities, communications—you’re putting in in a new interface with a new system,” says Walter. “Adding a third track—all that infrastructure that makes the trains run safely—requires a lot of systems expertise.”

Paskoff说，3TC的周末停电在提前六到九个月内被锁定。“这确实意味着我们全都参加了这项工作，并致力于日程安排。我们只是不能让这些日期滑行。”

So far, the schedule has not slid, even with the coronavirus. “Our workforce has not been hit,” says Paskoff, noting a few cases of self-quarantining. With ridership down 90% and trains running on a weekend schedule, “we identified some opportunities for additional time on the tracks. We have not missed a beat on the design side. On the construction side, things have changed a bit regarding where and when we can work.”