当Carr属性与威尔逊和榆树搬到MD的威尔逊和ELM时，2016年，开发商看到了一个为郊区D.C.地平线为郊区增加了突出的新财产。建立在一个计划未来的未来隧道和马里兰州过境管理局的轻轨紫线，该开发也代表了机会在运输枢纽的三座塔楼内创建近100万平方英尺的办公室，住宅和零售空间。但是，提供了该愿景，要求团队重大协调。它必须围绕现有和未来的地下基础设施工作，同时设计和构建上面的复杂结构系统和邻近这些元素。
Given the complexity of the project, Carr brought on Clark Construction to work with Shalom Baranes Architects while the project was still in schematic design to help with budgeting and constructibility, says Alison Wertzler, Carr Properties vice president of design and construction. “Carr wanted to know that we could do what we said we would do,” she says. “We needed Clark’s help from the beginning.”
在地下，该网站计划成为MTA紫线的西部终点。该地点还将允许乘客转移到华盛顿大都市区交通管理局的红线的邻近贝斯达站。此外，多用途Capital Crescent Trail系统最终将通过Bethesda下的新隧道通过该网站。Wertzler表示，与Montgomery County，MTA和其他利益相关者合作，该团队设计了一个计划为未来紫线和小径创建壳空间。允许团队围绕着它们。随着红线邻近的房产，来自地铁隧道的两个主要通风口和紧急出口楼梯也通过该网站上升。船员需要在整个项目中保持通风口和楼梯，没有停机。
所有现有和计划的地下基础设施都创造了“无情的几何形状”，Shalom Baranes Associates主任Jack Moyer表示，以及威尔逊和榆树的项目经理。“这是一个三角网站，带有铁路线，”他说。“网站几何形状本身没有引用。这只是通过该网站的斜线。“
该设计在地面创建了三个级别，也适应了壳空间和现有的基础架构。虽然这些要素纳入设计中，但团队提前决定，他们不会成为威尔逊和榆树的结构系统的一部分。“剪切墙设计是该项目中最困难而繁琐的方面，”结构设计公司Tadjer-Cohen-Edelson Associates助理助理。“大多数剪切墙必须在建筑物中转移。剪切墙显然无法穿过隧道，所以必须从车站的屋顶转移。“
地下元素
基于地质的基础，除了WMATA设施周围外，结构设计呼吁在大部分地点进行垫基础，其中包含30个4-FT-DIA沉箱，以避免现有轴的压力。帕斯科丘陵副总裁Pasco Umbrac表示，挖掘将带来自己的一系列挑战。雨寒说，周围的现有基础设施致力于“我们的挖掘中的混合袋，以及传统的挖掘支撑，”雨寒说。
Walls from the existing building, which were located slightly outside the new structure’s footprint, were retained and incorporated into the excavation design. “We were able to treat them like temporary support of excavation members and then just build our building inside them on two sides,” he says.
雨伞表示，该团队大量使用建筑信息建模，包括4D型号，确定设计和排序。“我们提前招募了我们的[虚拟设计和施工]群体，因为我们需要了解所有基础元素以及如何与挖掘发挥作用，并带来混凝土[工作]。”
Before excavation could begin in 2017, existing buildings on site were demolished, except a historic building—Community Paint and Hardware—that had to be relocated. For crews to successfully move the two-level structure to a new location a half-mile away, it was cut vertically into halves. Crews could then lift each half from the existing foundations with hydraulic jacks and move them on specialty trucks to the new site.
一旦挖掘开始，雨伞说时钟正在滴答。MTA在2018年底之前需要紫线的壳空间。从混凝土工作开始完成空间的工作人员有六个月。
The team turned shell spaces over two weeks early, and the focus shifted to above-ground efforts. The structural concrete project has the three towers—two residential and one office—set on a shared six-story podium. With limited space underground, the podium provides five floors of parking, which Wertzler says enabled Carr to get zoning changed to allow the towers to rise an additional 50 ft above Bethesda’s 250-ft height limit.
The podium also includes long-span spaces, such as a lobby and a 14-ft-clearance loading dock area that required seven structural transfers. WMATA’s two vents extend up into the podium and exit at the second floor. The egress stair exits at the ground level.
在结构上，讲台通过25层商业塔和两个住宅塔之间的扩展接头垂直分开，一个28个故事和其他31个故事。在排序工作时，克拉克将结构元素用于其优势。船员被分成了商业团队和住宅队，在协调但独立的范围内工作。该项目需要超过85,000码的混凝土，因此每个团队将该计划分开，分布倾倒。商业团队从下午7点涌入。傍晚，然后住宅队从上午3点倒入直到高峰时刻。
虽然工作进展顺利，但早期的租户签署也影响了设计和施工。当地福克斯5电视台同意将其业务转移到商业塔，这需要创建双层高度的工作室空间。该车站还需要屋顶上的卫星农场。艾哈迈德说卫星没有增加大量的死载，但确实存在提升考虑因素。
另一个延迟设计是一个60英尺长的两层天空桥，将两个住宅塔连接在28楼。Moyer表示，该概念是设计一种设计单个机械系统的一种服务，包括住宅塔。起初，他说，设计师考虑创造一个管，“但是这是一个你可以走过的桥梁。”Moyer指出，该概念还允许更容易地访问两座塔的居民等娱乐空间，例如游泳池。
A steel structure was devised for the bridge, but lifts were greatly limited by the capacity of the available tower crane. To reduce weight, Umbriac says the team devised a plan to remove the bottom chords from the bridge’s three trusses, install them first and add a metal deck to create a work surface for crews. Then the remaining portions of each truss could be placed, one pick per night over three nights. The bridge is seated on one tower with a 9-in. sliding connection on the other to allow for movement between the towers.
该团队广泛使用BIM来设计和排序工作，并专用18个月来规划项目的桥梁。“这是关于整个建筑物的努力，”虚拟设计和建设的克拉克建筑主管Ava Norton说。
虽然通过本网站的单独紫线项目被搁置在9月份，但威尔逊和榆树正在朝完成。预计住宅楼预计将于2021年初开放，并于2021年5月遵循商业建筑。
Wertzler credits the team’s early and consistent collaboration for keeping the challenging project on track. “If we weren’t working together to figure out the best solution—regardless of who had to work harder to make it happen—we wouldn’t be where we are today,” she adds.
