大约有18万名驾车者沿着275号州际公路沿着霍华德·弗兰克兰（Howard Frankland）桥穿越霍华德·弗兰克兰（Howard Frankland）桥，如果他们认为正在进行的建筑作品没有普通甚至引人注目的东西，则可以原谅。

Currently, the only visible sign of completed work for the mostly low-level, approximately three-mile-long bridge structure is the substructure still taking shape. Eyed from one project endpoint, the view of completed substructure work extends impressively into the distance.

自2020年下半年建造以来，佛罗里达州的运输部报道说，截至2月，新八车道桥梁基金会所需的3,006个桩中有1,200多个已被驱逐出境。机组人员已经建造了该项目的549个桥梁基础中的120个，并完成了计划中的549座桥柱中的110个和必要的226码头盖的38个。其子结构配置匹配了构成当前霍华德·弗兰克兰（Howard Frankland）的两个双桥（其中一种将保留到位的双桥）的配置，新的跨度将配备113个码头，以支持其112个跨度。

沿新出现的桥结构的三英里长的长度出现了数百个混凝土桩，柱子和码头盖。
照片由Archer Western提供

Despite the impressive achievement marked by those numbers, Greg Fullington, project executive for the Archer Western-Traylor Bros. joint venture leading construction of the $865-million design-build project, describes the work as “pretty standard.”

And while this project’s status as a mostly low-level structure doesn’t qualify it as a “signature” bridge, it’s certainly a big project for the Tampa Bay area, in more ways than one.

The new bridge will serve as an update and an expansion to the current Howard Frankland, which is comprised of two four-lane structures: a late-1950s-era bridge that carries traffic heading northbound from St. Petersburg and a structure completed in 1990 that handles southbound I-275 traffic from Tampa.

“扩张”来自新大桥的capacity being twice that of the existing four-lane spans. In all, the new bridge structure will comprise eight total lanes, including four general-use lanes for southbound traffic along with four tolled express lanes—two each for northbound and southbound.

Once the new bridge is completed in late 2025—per the schedule—southbound traffic will switch over to the new bridge and its four general-purpose lanes. Crews will then perform maintenance on the current southbound bridge before switching northbound traffic from the oldest span and onto the 1990s bridge.

The new bridge span doubles that of the existing structures and will feature eight travel lanes, including four tolled express lanes.
Image courtesy BCC Engineering

Straightforward, But Tricky

To date, the Archer Western-Traylor Bros. joint venture is on schedule despite slower-than-expected progress with pile-driving work, says Fullington. He credits night drilling initiated during early schedule slippage with keeping the project on track despite the delayed pile work.

另一个帮助使承包商努力加快的项目是，该州批准了佛罗里达部的环境保护部颁发的特殊许可，用于使用“混合区”，以衡量由钻探和其他操作引起的浊度。从码头位置延伸了500英尺，承包商能够从该区域的边缘进行测量浊度，而不是与工作相邻。富灵顿说，迄今为止，承包商一直保持在限制范围内，帮助使工作人员生产效率。

Since construction commenced in October 2020, crews have driven 40% of the necessary 3,006 piles. Like Fullington, Marianne Brinson, senior project engineer with Atkins, the project’s construction engineering and inspection firm, seems to downplay the project challenges as she describes construction of the bridge substructure as “straightforward.”

这可能是正确的，但与此同时，坦帕湾的地质学一直在为团队提供一些曲线。富灵顿说：“这个范围当然是该项目最具挑战性的范围。”“这是非常困难的基础地质。”

Well-known for its irregularity, Tampa Bay’s geology can vary in seemingly random and isolated spots. For example, on numerous occasions—and as designed—the contractor has had to use the common method of splicing piles to reach bearing capacity. Sometimes, though, Fullington says, along the same pier line that required a spliced pile to reach capacity, crews have struggled to drill through rock.

富灵顿说，这种情况在93号码码头上以极端方式播放，船员必须在岩石上钻探，以达到一堆75-78英尺的最小尖端。他说，沿着约50英尺远的同一个码头，机组人员将拼接的桩驱动到约250英尺，而没有“接近容量”。

This view from the west end of the project shows how the contractor is working at both ends of the bridge project.
照片由Archer Western提供

Daniel Raymat, director of structures for BCC Engineering—and engineer of record for the bridge structures—concurs with Fullington that the project’s variable rock layer and unique soil conditions have “probably been the biggest challenge.”

From the construction of the two existing structures, engineers had plenty of historical data to rely upon as they precisely designed each of the 113 piers for the specific conditions they anticipated for each location.

Raymat解释说：“每个码头都必须为特定的土壤条件进行独特的设计。”他补充说，堆长度从60到220英尺不等。

尽管他们提供了广泛的历史信息，但“我们在任何给定的码头都不知道会有多少可变性，” BCC执行副总裁Ariel Millan补充说。

团队经验ected to see anywhere from 60 to 100 ft of variability between minimum and maximum pile depths on a single pier, Millan adds. Still, without being certain of what to expect at every pile location, “you have to assume you’re going to have to splice a certain number of piles.”

尽管承包商预计最终的桩数将超过3,006的官方估计，但合资企业是否给自己足够的多余堆仍然有待观察。富灵顿说，最终需要的数字“对我们来说是一个很大的风险”。尽管他补充说合资企业“在我们的估计中确实携带了额外的长度……我们看到的桩持续更长”，而不是比预期的短。

The 6.4-mile-long project also includes a causeway portion at its west end.
照片由Archer Western提供

到目前为止，一切都很好

Like the bridge builders, FDOT project engineer Greg Deese agrees that the current phase of construction is the “most critical.”

他说：“一旦我们离开地面，这项工作就变得更加简单。”“一旦堆驱动完成，完成应该是一项非常好的工作。”

To that end, FDOT states that beam placement is slated to start by late spring, followed by the commencement of deck construction by early summer.
So far, the contractor’s ability to stay on schedule, despite the underground hurdles, is earning kudos from FDOT.

Deese said what has stood out to him when visiting the site is the safety consciousness of the crews, noting that “you can tell they’re taking pride in their work.”

Despite the hazards of marine work, the contractor says the project has been able to achieve a good safety record to date.
Photo by Scott Judy for ENR

Brinson, with Atkins, has a similar view, noting that the joint venture’s point of surveying field workers as part of its monthly partnering effort has shown workers are feeling positive so far.

对于布林森来说，这些调查证实了“很明显，每个人都显然表现出对彼此的尊重水平”，包括野外工作人员。

To that end, Fullington says the joint venture has utilized such tools as recognition of Crews of the Month and other ways to keep employees engaged and otherwise proud to be working on this landmark project. The focus on workers is key to productivity, safety and keeping staff satisfied and on the payroll, he says.

Overall, despite what he calls an “extended learning curve” with the foundations, Fullington says “we’re where we expected to be, on schedule.”