安联球场
Saint Paul, Minn.
Best Project, Sports/Entertainment
Key Players
Owner:明尼苏达州联合足球俱乐部
领导设计公司：人口
General Contractor:莫滕森建筑
结构工程师：沃尔特·P·摩尔（Walter P Moore＆Associates）
Civil Engineer:Loucks Inc.
MEP工程师：ME Engineers
Owner’s Representative:Tegra Group
Like the lakes of Minnesota, the undulating exterior of the $250-million Allianz Field in St. Paul appears sparkling and bright in the sun, yet transparent and refractive in the shade. The look of the new home of the Minnesota United FC was created by wrapping the 20,000-person stadium in 88,000 sq ft of transparent and laminated fabric known as polytetrafluoroethylene (PTFE), making it the largest PTFE installation of its kind in North America.
By stretching the fabric over the stadium’s sweeping steel ribs, lead design firm Populous aimed to mimic the motion of Minnesota’s abundant waters, says Phil Kolbo, associate principal at Populous and lead designer on the project. When backlit with 1,700 LED lights, the design’s intent is to invoke the look of the Northern Lights.
他说：“我们有一个想法，可以承担所有这些品质，例如反射，折射和半透明 - 水的所有特征。”“从概念的角度来看，要采取这个想法并使之成为现实是一项艰巨的任务。”
除了设计属性外，PTFE还可以跨越30英尺。该团队能够节省大约100吨的钢，这是更传统的覆层所需的。
“To make this a signature stadium, it was all about the PTFE,” says Troy Blizzard, project director and vice president of operations at Mortenson Construction, which served as the construction manager at-risk.
Populous及其亚公民在设计早期与Mortenson合作，使PTFE系统成为现实，每周开会两年。尽管它似乎是一个连续的包裹，但PTFE分为部分。原材料从中国运到加拿大，将其切成梯形形状，并用折叠并运送到现场的大型床单中进行热焊接。
为了满足PTFE部分的确切公差，从设计到制造，广泛使用了建筑信息建模。
到达现场后，将部分展开，抬起并螺栓固定到位。安装时间表很大程度上由合成织物的热膨胀驱动。科尔博说，必须在温暖的夏季安装PTFE部分，以便在寒冷的月份收紧，但在夏季仍然保持紧绷。
全年的织物的潜在膨胀和收缩在此过程的早期是一个关键问题，因为团队需要知道织物如何反应，而钢肋骨也对温度变化做出了反应。
“One of the interesting challenges we found was that no one in the fabric industry had really looked at the thermal expansion of fabric,” he says. “As it turns out, PTFE expands faster than metal does, and when colder, it shrinks faster. So it would not be an issue.”
除了必须满足PTFE安装的特定季节性截止日期并为运动场铺设草皮外，该项目还面临其他时间表的挑战。
Two acres of land on the site that were occupied by retail spaces from an old mall needed to be demolished to make way for the north end of the stadium. The original schedule called for demolition in August 2017, but the date was pushed back to November to accommodate tenant lease agreements.
The team resequenced the project to stay on track for an early 2019 completion. Work on concrete, mechanical and electrical had to be done in 10-hour daily shifts, six days a week, from July to November. Rather than build the stadium in a typical circular fashion, steel crews built roughly two-thirds of the stadium in a U-shape. Once the last retail spaces were demolished, including a Rainbow Foods supermarket, the remaining third of the stadium could be built.
利用预制的建筑组件和系统（例如位于体育场冠层下方的金属桁架）也有助于加快建筑。
该地区的大风是确定建造体育场的最佳方法的关键考虑因素。根据风洞中测试体育场模型的结果，该团队决定将330个岩石锚定在地下65英尺的地下，以保护PTFE和平板级元素免受风载。岩石锚定工艺尤其征税，因为在安装过程中将地面冷冻，并且需要在亚冻结温度下使用水基灌浆。
新体育场于2019年5月按时完成并按预算完成，为球迷们提供了一个非常亲密的游戏环境，最接近球场的座位最接近17英尺，而最远的座位距离酒店则只有125英尺。一个2,850个容量，安全的支持者部分（被拿到Wonderwall）游览了联盟最陡峭的耙子。
暴雪将该项目的成功归功于人口众多，莫滕森（Mortenson），所有者和亚顾问之间的牢固合作伙伴关系，并指出，核心小组在目标实地项目中也将核心集团合作近十年。他说：“能够与您认识的人建立这样的复杂的东西，并且已经从斜槽中信任的是非常强大的。”
