高生活：定位美国最高的住宅建筑的地板

Author:T/F/D

On Manhattan’s ‘Billionaire’s Row’, a new glistening New York skyscraper nears completion. The Central Park Tower rises to 1,550 feet (472 metres) tall, the tallest residential building in the world, and the second tallest building in the city, second only to One World Trade Center. Construction began in 2014 and Pinnacle Industries II, LLC installed the core super-climber forming system in 2016. Due to the height of the building, Robert Mandelbaum, Survey Engineer at Pinnacle Industries II, used a GPS solution − a Leica Geosystems GNSS system − to locate the layout of each new floor.

A new approach to monitoring

Central Park Tower will contain 179 homes with one of the most expensive views in the world. 300 feet (over 91 metres) above the street, the Tower cantilevers to the east, creating views of Central Park for all north-facing residents. The elegant exterior gives away nothing of the complexity of the construction or the challenges of keeping the building’s footprint consistent and accurate. Before each new floor could be built, Mandelbaum needed to provide the Pinnacle Industries II team with reliable coordinates to set out the structure. On a smaller building, surveyors would use optical instruments to do this from the ground, but above a certain height that becomes impossible. “Because it’s so high, we cannot use conventional transits [transit levels] to establish location,” explains Mandelbaum. “On a bad weather day, that’s just not happening. At 1500 feet (over 450 metres), you cannot see with a traditional instrument.” So, for the first time on a residential construction site, Mandelbaum used a GPS-based solution.

Establishing control lines for each floor

The Leica Geosystems GNSS-based monitoring system works by GNSS receivers being placed on the outside of the building − the hydraulically climbed protection screen enveloping the structure in this case − and acting as control points that move up as floors are completed. The system used on the Central Park Tower construction included fourLeica AS10 SmartTrack antennas与共同认同的360棱镜，一个Leica GM30 GNSS monitoring receiver，Leica Viva TS15 Total Station（前身Leica TS16) andLeica Spider和Leica GeoMoS monitoring software. Mandelbaum explains, “The protection screen climbed up alongside the building, so I put all the equipment on it. I didn’t have to worry about me physically moving it up because it was fixed to the inside of the screen. The GNSS antennas, I would place on the perimeter, on each corner of the building as far as I could from each other. They would give me coordinates, and using that I was able to establish control lines.” The control lines mark out where the building slabs-edges, and column and walls will be positioned and located.

在高压环境中经过证实的准确性

Mandelbaum说，该系统对Pinnacle II团队的最大好处是它的准确性，在任何建筑工地工作时都令人放心，尤其是高层。他使用传统技术检查GNSS测量值。“为了验证访问线或控制线从地板到地板的堆叠，每10层，我将使用一条旧学校钢琴线。从字面上看，一条钢琴线，将其掉到角落。我会将良好的80磅重的重量绑在底部，然后我会用规则对地板上的访问线进行物理检查，并与控制线一起检查。它在那里，16^th一英寸（1/6英寸= 1.55毫米精度）。它只是证明这是对的。”

Leica Viva TS15总站还用于建立控制线的位置，作为对溶液的另一项独立检查，可以针对天线读数引用。整个站点通过在GNSS天线下共列的棱镜定位自身。Mandelbaum解释说：“我会知道每个天线根据笔记本电脑上的解决方案在哪里。我会采用离我最远的天线，我也会寻找时间解决方案。我将同时插槽并射击（与总站测量）天线。而且，如果我在笔记本电脑上看到的数字相同，那么我将使用它。”

Easy to use software displaying real-time data

Despite being new to the GNSS system, Mandelbaum and his partner found it easy to use. With support from Leica and by filming some of the processes on his phone for reference, he says “it was pretty simple.” A self-confessed mechanic rather than a ‘software guy’ Leica’s software programs − the Leica Spider Software Suite and Leica GeoMoS Now! − provided easy access to the real-time data essential for establishing control lines. “There were a few steps I needed to learn, and that was that. It was a piece of cake.”

中央公园的建设将惠塔ete in 2021. Now that Mandelbaum’s part in the build is finished, he plans to use the Leica Geosystems GNSS system again: “If I can, I will. It has a track record that it works.”

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