A Concrete Parade

There’s quite a bit to catch you up on with the River ‘S’ Bridge replacement project after a busy couple weeks of other Ridgefield National Wildlife Refuge milestones, like the completion of Douglas fir felling on the Carty Unit and the opening of the brand new Carty Lake Trail.

For the last couple weeks, the focus has been on the construction of two piers. These are the legs of the bridge that are in the water. To perform this task, a new barge-mounted crane was brought to the work site in late April. Ceccanti and their subcontractor team worked tirelessly last week on this multi-step process that included drilling, setting the rebar cage, and pouring concrete at Pier 2. This week, they plan to complete Pier 1 in similar fashion.

This is work that must be completed quickly and without interruption to avoid water refilling the drilled shafts and to allow the concrete to set properly. To accomplish this important step, work hours have been adjusted to 24 hour shifts, which is likely to continue through May. And if you happened to be in the area this past weekend, you may have noticed a parade of concrete trucks going in and out of the River ‘S’ Unit. The unofficial count of our staff observers was 47 concrete trucks!

A little more about the piers:

  • They are 10 feet diameter and are 100 + feet deep below the Lake River bottom

  • The holes are dug inside a casing that keeps the water from filling the hole

  • Once the designated depth is achieved, the rebar cages are lowered into the casing, followed by concrete

  • At about water level, the 10-foot shafts taper down to 6-foot shafts. So the shafts will look like 6 feet because the 10-foot section will be largely submerged and out of sight.

Looking ahead, a lot of steps remain. But here’s a rough idea of what’s to come:

  • 10-foot piers are completed

  • A 10-foot pier will be constructed West of the railroad tracks

  • Then a pier will be constructed at each end of the bridge for a total of five bridge legs

  • The two water-based piers, which are 130 feet apart, will eventually be spanned by three precast concrete girders, each 130 feet long