In 1939, the U.S. Army Corps of Engineers’ LaGrange Lock and Dam was completed on the Illinois River near Beardsville, just north of where the Illinois meets the Mississippi. It’s a key shipping point for commodities flowing to all points south on the Big Muddy.

After 81 years of service with only minor repairs in 1986 and 1988, the 600-ft-long lock and dam was past due for a refresh when AECOM Shimmick began the Corps’ $117-million rehabilitation last year.

“The LaGrange Major Rehab/Major Maintenance is the single largest construction contract ever executed by the Rock Island District,” says Col. Steven Sattiger, commander and district engineer of the USACE Rock Island District. “In the last 20 years, only one other Rock Island project exceeded the magnitude of the LaGrange project, but that project was split into multiple contracts and took nearly 10 years to execute, unlike LaGrange, which was substantially completed in a single construction season.”

Frequent flooding and temperature extremes combined with high usage resulted in significant deterioration of lock concrete and the decline of mechanical and electrical systems’ performance and reliability. The locks even had grass growing through the aged concrete.

Aecom Shimmick的任务是脱水，卸下其锁定面，安装新的预制面板，并用嵌入式装甲板重建锁定面，以提高耐用性。

项目总监鲍勃·惠勒（Bob Wheeler）说：“这将是一项非常困难的工作。”“在夏季关闭之前，我们保持了锁定的打开状态，并刚刚在锁周围进行了施工活动，这可能会干扰河流的交通。以这种方式完成工作真的很难。”

Work began in July on a 90-day lock closure and dewatering, but AECOM Shimmick was supposed to get several closures throughout the two-year project. The flooding of spring and summer 2019 meant that Wheeler and his team needed to compress work activities into a reduced, single closure window of 90 days from July to October 2020. With such a tight window, Wheeler said he knew it was going to be “incredibly difficult.”

The AECOM Shimmick team would need to install new miter gate anchorage points and new programmable control systems for opening and closing the miter gates. Since the site floods so much, the Corps wanted to replace traditional hydraulic cylinders with new technology.

“When they go underwater, [hydraulic cylinders] tend to leak and that’s going to become a problem,” Wheeler says. “It’s a cost and maintenance issue.”

新的升力机制代替了液压缸，而是使用旋转执行器的主轴技术，而纺锤技术以前尚未用于锁。该军团适应了使用纺锤体打开和关闭舱口和鱼雷托架的潜艇的锁的技术。

Rotary actuator manufacturer Moog provided detailed instructions for their installation. The implementation needed to be exact for the actuators to work properly.

惠勒说：“他们的占地面积比传统的圆柱体要小得多。”“当我们测量旋转执行器所适合的轴和样条时，它必须在十分之一英寸之内 - 基本上是在这样的锁和大坝中，如果它在八分之一之内，那就很好。”

Laser scanning was used to pinpoint the installation points of the actuators.

河滨锁和大坝紧密占地面积的重型设备包括在陆地上的300吨起重机，上游的300吨起重机以及舱壁下游的300吨起重机和锁。一辆150吨的起重机位于河滨墙壁外的驳船上，并在房间的两辆60吨的起重机上。在陆上墙上，有两辆130吨的起重机和另一台60吨的起重机。这些起重机用于放置锁装甲以及锁墙的新混凝土，起重机使用桶放置。

AecomShimmick’s crews logged 200,000 worker hours in three-and-a-half months. Coordination and communication of heavy equipment, at peak, included 286 personnel working six 10-hour double shifts in the lock chamber, which is 600 ft long and 110 ft wide.

惠勒说：“我们从锁的两侧工作。”“双方同时。这是非常了不起的。我们有一个很好的计划系统，我们将所有这些内容预先计划。它类似于精益，但更加专注于吸引领域和手工艺工人进入其中并每天提供反馈。”

水下建筑分包商JF Brennan在威斯康星州的拉克罗斯（La Crosse）外面提供了海洋计划和潜水员。惠勒说，他们必须在舱壁上潜水，必须清理并取出。所有的阀门也必须修复。1939年的大坝有一个固定的堰来挖掘并清理干净。Brennan和Aecom Shimmick用混凝土填充了它，因此它不再起作用，也不是运输的责任。现代清洁系统是使用新的控制系统安装的。

“您只是无法像通常在模板的地方那样放入混凝土，然后将其放在三条屏幕线中并完成。必须非常准确。”惠勒说。“然后从锚固式出发的结构系统就在混凝土中。我们将其切出，然后用锚向向下钻了大约6英尺，将结构放入，然后将其放入该结构，然后将其螺栓固定在结构上，然后将旋转执行器固定在该结构上。这真的就像加工一样 - 您通常会在电力屋里做的工作，但是在锁的中间。”

Despite the tight 90-day window to do all of the lock work in the dry, AECOM Shimmick got the project completed on time and the Illinois River has been open for barge shipping since mid-October. Work on five of the eight locks and dams along the Illinois River has been completed.