由华盛顿州运输部运营的40年来为该国最大的渡轮系统建造了第一个新码头，这意味着要应对棘手的地点条件和文化敏感的问题。耗资1.87亿美元的Mukilteo渡轮终端需要多个合同和独特的雨水系统。

The terminal is replacing a 63-year-old structure that is part of State Route 525, Washington State Ferries’ (WSF) second-busiest ferry route with 4 million riders annually and an expected walk-on ridership increase of 124% by 2040. Hemmed in by other development, the new terminal is built one-third of a mile east of the existing structure on what was an abandoned World War II-era U.S. Air Force fueling station.

But environmental contamination wasn’t the only concern, as the site is also steeped in cultural significance. It was the signing location of the 1855 Point Elliott Treaty with dozens of Native American tribes and nations.

The combination of culturally sensitive land with potentially contaminated areas required raising the terminal site 7 ft. “We needed to be very sensitive to that cultural significance, and that really drove so many decisions for the project,” says Dan Alire, project engineer for KPFF Consulting Engineers.

“It certainly had its challenges,” Alire says about the requirement that there be virtually no on-site excavating. The team had to find a “happy medium” in elevating the site as much as possible to allow burying all utilities without excavating, and to protect against coastal flooding, yet not overextend the budget with expensive fill. A tidal range of up to 18 ft made design trickier, as the overhead passenger loading bridge had to work at both low and high tide, with the proper slope to accommodate the Americans With Disabilities Act. “It was balancing a lot of things to get the finished grade elevations,” Alire says.

科比Bullamore WSF施工经理说,test borings set the boundaries of the culturally sensitive and environmentally delicate areas, and an archeologist on site ensured they followed all tribal agreements.

该地点需要一个独特的雨水系统，该系统由生物娱乐设施，模块化湿地和大型透明的路面砂过滤系统组成，所有这些都可以一起处理水。“我们建立了整个区域，” IMCO Construction的项目经理尼克·米勒（Nick Miller）说。“我们基本上放了一个巨大的过滤器。这是一个相当大的区域，清理和排放。”

Crews uncovered unexpected site conditions. The existing shore riprap was thought to be up to 5 ft thick, but as teams started drilling for pile placement, it was found to be up to 10 ft. “We had to do a lot of extra work to remove that and armor that slope,” Bullamore says. “That was one of the big challenges at the beginning.”

多个合同

The project, which started in 2017 and wraps up this spring, includes the terminal, a maintenance building, passenger overhead loading, a toll plaza with four toll booths and seven holding lanes, an in-water docking and loading structure, a transit center for connections to buses and trains and improvements to intersections and the waterfront promenade.

Because of the concerns about work stoppages involved with the site’s sensitivity, the project was broken into four different contracts to ensure it moved forward. Bullamore says this added complications in coordination, but the contractors worked well together and kept the project moving forward to an on-time opening of the building. He says it also opened the project to contractors with unique specialties.

猎户座海洋集团建立了基金会栈桥,high-risk portion, while IMCO handled the deep stormwater system with a trenchless technique to avoid disturbing the site. Manson Construction executed the remainder of the marine work, and IMCO, in a separate contract, constructed the building, roadwork and utilities. “The different contracts and phasing were an important part of how this kept moving forward and how we mitigated some of the major risks we knew existed,” Alire says.

由于多个州机构，穆基尔特奥市和11个联邦认可的部落都是该项目的一部分，因此协调并没有停止承包商。阿里尔说：“有很多人，有很多独特的部分。”

The in-water work first required dredging 23,500 cu yd and removing 3,600 creosote piles, 4% of the creosote piles in the Puget Sound. Charlie Torres, WSF project manager, says Orion was able to complete that work in one year instead of the projected two.

最大的挑战是实施一种新的结构系统来处理斜坡的地震考虑，并在传统系统中最多运动7英尺。通过与华盛顿大学合作，该团队设计了一个充满混凝土的钢管系统，以固定的桩途径来控制运动，从而将位移限制在不到一英尺的位置。Alire说：“这是您在大多数项目上都不会做的事情，但是它在这里符合我们的标准。”18luck官网

During placement of large-diameter shafts, some up to 7 ft in diameter, the first started sinking in an unexpected way. “It was a quick all-hands-on-deck [moment],” Alire says. “We got the shaft stabilized and finished construction.” They solved the issue by drilling out the interior of the pile and placing a slurry mix inside with enough hydrostatic pressure to stabilize the shaft before installing the remainder of the concrete casing.

Throughout the marine work, Kelli Rider, Manson Construction project engineer, says it was a technical project with unique elements such as heavy lifts, tight tolerances and tidal work areas. The steel items were fabricated off-site and set in place, including a nearly 400,000-lb vehicle transfer bridge that make the pick geometry challenging.

Rider说：“所有结构性钢材物品都具有紧密的公差，以便为系统（车辆传输跨度和架空装载驾驶室）在任何潮汐高程中正常运行。”“该项目的协调比大多数人更广泛。所有元素都必须以一种不相互冲突的方式安装。”

The terminal building—designed in the form of a 30-ft by 100-ft Coast Salish longhouse with a large gathering hall, with views of the water and sustainable features—is aiming for LEED Gold certification and includes photovoltaics, rainwater harvesting and natural building ventilation.

该建筑于2020年12月29日向乘客交通开放，但工作一直持续到春季，以拆除了以前的航站楼和旧的固定车道，以与525号高速公路建立新的连接。