Sonoma County, California Bridges: Rockpile Road Bridge across Warm Springs Creek (2)

September 2014 (38.71500 Degrees, -123.01583 Degrees) Rockpile Road Bridge

The photo above shows the view from the west abutment of the Rockpile Road Bridge. Warm Springs Dam can barely be seen through the truss in the photo. The view from the east abutment can be seen in the photo below. Not only is this a long bridge but as Eric Sakowski mentions on his website it is also a very tall bridge. The bridge deck is 355 ft above the creek bottom. The bridge was built before the dam raised the water level in Warm Springs Creek.

It looks like the superstructure is attached to the piers with two bearings and a damper in the center to absorb energy for wind and earthquake loads. Hopefully the county has performed an analysis for this bridge to ensure it can resist a large earthquake on the San Andreas Fault (20 miles away) and the Healdsburg fault (2 miles away). Sonoma County performed a strategic planning assessment of its bridges following the I-35 bridge collapse. Their report can be found on this website.

Sonoma County, California Bridges: Rockpile Road Bridge across Warm Springs Creek (2) by MarkYashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Sonoma County, California Bridges: Rockpile Road Bridge across Warm Springs Creek (1)

September 2014 (38.71500 Degrees, -123.01583 Degrees) Rockpile Road Bridge

Sonoma is a big county that extends from San Pablo Bay in the east to Bodega Bay in the west. We've spent the last 30 days looking at different types of bridges in Sonoma County. Today's bridge, the Rockpile Road Bridge (20C0438) has the longest span (753 ft) and the longest length (1780 ft) of any bridge in Sonoma County. In fact, it has the 21st longest main span of any continuous truss bridge in the world (according to the Wikipedia Website). A continuous truss has no locations along its length of zero moment. Still, I would imagine that the bridge was built as two cantilevers and made continuous in the middle.

In the photo above the Warm Springs Dam is to our left and we can see the bridge spanning an arm of the reservoir called Warm Springs Creek. The dam was constructed by the U.S. Army Corps of Engineers and completed in 1983. The bridge was completed in 1978. We'll take a closer look at this interesting structure tomorrow.

Sonoma County, California Bridges: Rockpile Road Bridge across Warm Springs Creek (1) by MarkYashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.