Tuesday, July 25, 2023

US-98 Bridges over Santa Rosa Sound in Okaloosa County, FL

(Bridge Hunter broke Mar 22, 2023; Satellite)

Why am I bothering talking about replacing a UCEB (Ugly Concrete Eyesore Bridge) with a couple of UCEBs? Because I have never before seen the use of a steel framework to help pound pilings into the ground. And this is just for temporary pilings.
FDOT Northwest Florida added
Crews are constructing the temporary work trestles required for the construction of the new Brooks Bridge in Okaloosa County.
Although the work trestles are temporary, they require a strong foundation, deep within the ground. Here is a look at pile driving operations underway near the base of the bridge in Fort Walton Beach.
First, crews assemble a large auger (shown in the first photo) to drill 10 feet into the soil. This essentially creates a large “pilot hole” to stabilize the pipe pile as it is hammered into the ground.
The second photo displays a pipe pile being placed into steel framework, which acts as a template to ensure that the piles (30 inches in diameter and 80 feet tall) are placed and driven into the drilled hole.
The third picture shows crews assembling the hammer and placing it in the steel lead system, which will keep the pile and hammer aligned.
The final photo shows crews placing the crane-mounted hammer and lead over the pipe pile. With everything in place, the diesel-powered hammer drives the pipe pile into the ground.
Once built, the temporary trestle will provide access for cranes and heavy equipment to reconstruct the bridge over the Santa Rosa Sound without the use of barges. The $171-million Brooks Bridge replacement project includes constructing two new, parallel bridges that will increase capacity to six travel lanes from the current four-lane bridge that opened in 1966. Project completion is estimated for summer 2027.

The lower parts of the bridge over shallow water used concrete girders and the part over deeper water used longer steel girders.
Street View, Feb 2020

I think that green thing is a vibrator. Note the hydraulic hoses that power the vibrator. I presume they are driving the columns for the steel framework here.

FDOT Northwest Florida added

GetTheCoast
The new bridge will carry 6 lanes instead of 4, will improve the vertical clearance from 50' (15m) to 65' (20m) and widen the channel from 140' (43m) to 150' (46m). It has a budget of $171m, and it is expected to be done in mid-2027.

The permanent bridge will require driving 348 concrete pilings. To help reduce the impact of the noise, pile driving won't be done when the sun is down. [TheDestinLog]

The current bridge has "an average annual daily traffic count (AADT) of 66,000." [nwflroads]

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