Buffeted by hurricanes, northwest Florida’s largest-ever infrastructure effort is finally seeing the light at the end of the storm. The three-mile-long bridge across Pensacola Bay is expected to reopen to traffic this spring after an ongoing replacement effort abruptly became an emergency repair job as well.

2020年9月15日，萨利飓风进入墨西哥湾沿岸的途径使阵风超过39英里 /小时，佛罗里达州的运输部（FDOT）常规预防措施，将横跨彭萨科拉湾的桥梁关闭到交通中。没有人知道至少要六个月才能重新开放。

A last-minute eastward shift in Sally’s track brought the storm’s eye to within 30 miles of the bridge and its partially complete parallel structure, being built by Skanska USA Southeast. At some point during the storm, wind-driven waves freed 27 construction barges from their moorings, scattering them into the churning bay. An unknown number of vessels struck the existing bridge at multiple locations, completely severing some spans and leaving deep gashes in others.

It would be several days before inspections revealed the full extent of damage. FDOT’s drone surveys and other preliminary images left little doubt that a challenging restoration effort lay ahead. FDOT and contractor representatives did not make themselves available for interviews, but the agency has shared many aspects of how the recovery and repair effort has unfolded via press releases, video updates and its public information website.

地标穿越

Opened in 2019, the damaged bridge was the first project completed as part of FDOT’s $430-million program to replace a now decommissioned 1960s-era bridge between downtown Pensacola and the suburb of Gulf Breeze with twin three-lane structures. The project, which also included a new interchange in downtown Pensacola and improvements to Gulf Breeze approach roads, aimed to expand capacity for commuter traffic, which had reached 55,000 vehicles a day, and upgrade a key hurricane evacuation route.

The design-build project began in 2016 with Skanska, lead designer WSP and Eisman & Russo Inc. Each 65-ft-high steel-reinforced precast bridge sports a 375-ft-long, 83-ft-high steel-plate arch supporting a 10-ft-wide multiuse path. Prior to Sally, the parallel bridge was on track for completion in late 2021.

But in the aftermath of Sally, what had been a largely uneventful construction process spiraled into uncertainty. As the storm left the area, FDOT and the team mobilized inspectors to assess the condition of both bridges, while eight dive teams evaluated underwater footings and potential debris damage.

At the outset of the inspections, Eisman & Russo senior project manager Glenn Peterson said in an FDOT-produced video that while the surviving bridge spans appeared in good shape, the team had to carefully scrutinize the structural load carrying capacity of individual components.

“The beams are the easiest to see, and they were really badly affected in several areas,” Peterson said. “When we can see the load-carrying steel member has been damaged, we have to consider how badly it’s damaged. When we see it’s exceeded a certain point where it can’t be repaired, we have to replace it.”

Damage assessments revealed that 70 155-ft-long beams required replacement, along with 14 of the 250,000-lb trophy pieces and eight 150-ft by 59-ft spans. Another 14 spans required partial replacement, while 12 spans of the multiuse path had to be rebuilt.

尽管批评了其前赫鲁里奇准备工作，但Skanska仍继续担任首席承包商。FDOT设定了将桥梁完全维修并在3月之前开放交通的目标。Skanska与另外两个承包商和四家打捞公司一起增加了资源。

根据Skanska的声明，维修工作人员增加到了近400名手工艺和工作人员，他们处理拆除和重建，打捞和桩操作以及混凝土制造。设备资源也得到了增强，包括增加了五只驳船的起重机来替换萨利飓风期间损坏或丢失的设备。

Other existing bridge construction assets for the parallel bridge would likewise benefit the repair effort. A precast yard established in nearby Bayou Chico stepped up fabrication of trophy pieces and beams, with additional piles supplied by a separate precast facility in Tampa.

在维修工作可能进行之前，承包商必须进行广泛的拆除工作，以去除受损的部分以及地下混凝土和钢碎片。还有问题的问题是，将四个任性的驳船放在结构下，而不会引起其他结构问题。承包商采用了多种方法来尽可能快速，安全地删除损坏的组件。根据FDOT网站的说法，一种方法涉及使用配备有自行车的移动运输（SMPT）的专业驳船，该驳船位于跨度下的范围下。

在船员将跨度沿码头的中心线上方切开后，SPMT抬起并将每个部分移到驳船的另一侧，以转移到第二驳船上。然后将部分运输到岸边区域进行拆除和卸载。较大的碎片被输送到人造礁石遗址。

Zeta飓风朝路易斯安那州海岸驶去时，活动的喧嚣被打断了。随着驳船和设备在远离桥梁的安全位置重新安置并停泊，驶出风暴，Zeta通过而不会造成进一步的损坏，从而使维修工作迅速恢复，尽管损害评估仍在进行中。

Eisman & Russo Brett Pielstick再保险项目总监ported in an FDOT-produced video that some areas that were unsafe weren’t cleared for reconstruction until mid-November. “Dive boats are everywhere to help us complete our assessment so we know exactly the scope we have to do,” Pielstick said, adding that Skanska also resumed construction on the parallel bridge and landside portions of the project. FDOT has not said whether the repair effort has affected that project’s level of activity or completion schedule.

By December, pile-driving for new spans was underway in earnest. According to FDOT, the process was synchronized with removal of damaged trophy pieces and waterline footings, followed by saw-cutting the four-pile clusters at the mudline. A 20,000-lb diesel-powered hammer drove new piles in clusters of six to avoid conflict with remnants of the old piles, followed by installation of a new footing and trophy piece.

December also brought another unwanted sense of déjà vu, with FDOT reporting that a Skanska-owned barge had broken loose and become stuck against private docks near the bridge. Along with reviewing its mooring practices, the company launched an investigation with state and local authorities to determine if the line connecting the barge to the sea floor had been severed intentionally. Results of the investigation have not been made public.

专注于Finishing

该项目团队在1月中旬实现了另一个维修里程碑，FDOT宣布了第一个新的桥梁甲板的混凝土倾倒开始。该机构还报告说，所有新桩和光束的铸造都已完成，预计安装将于2月底完成。根据FDOT的剩余时间表，桥梁上的横梁勃起，甲板倒入和非结构性维修计划于3月完成。重新开放的最后一步 - 隔壁的墙，条纹和电气工作 - 将在月底完成。

Though it seems likely that FDOT will complete restoration work on time, many questions remain about the incident itself, including responsibility for a final cost that has yet to be determined. From the outset, FDOT has publicly asserted that “once the situation is fully assessed, and damages are fully understood, appropriate parties will be held responsible for the repairs.” For its part, Skanska has said little beyond initial public statements that it had done all it could to secure its construction barges prior to the change in Sally’s storm track.

“The sudden shift in the intensity, direction, and duration of the storm was unprecedented and entirely unexpected by the entire Pensacola community,” a company statement said. “Unfortunately, it was neither safe nor feasible to attempt the removal of barges and other equipment in the brief period between the storm’s sudden intensification and its ultimate landfall.”

Whatever public plaudits Skanska may receive from its contribution to restore the bridge will likely be overshadowed by the dozens of lawsuits from local businesses and property owners claiming economic losses as a result of the bridge closure. The company is awaiting a federal court to rule on its assertion that maritime law applies to the incident, thereby limiting liability to each barge’s approximate value, which range in legal filings from $125,000 to $550,000.

目前，项目团队的重点是履行彼得森一开始表达的承诺 - 彭萨科拉湾桥（Pensacola Bay Bridge）恢复了75年的完整设计寿命，“因此我们拥有全部服务，而不是服务水平降低。”