Sacramento County, California Bridges: Greenback Lane Bridge across the American River

August 2013 (38.68194, -121.17583) Rainbow Bridge

There are also several old bridges that cross the American River in Folsom.

We previously looked at the 1917 Rainbow Bridge that carries Greenback Lane across the American River in 2009. The city has built a nice viewing area to look at the Rainbow Bridge (and at an adjacent Truss Footbridge).

The Rainbow Bridge (24C0067) was widened in 1969 but still has only a 25 ft wide deck. The bridge carried over 31,000 vehicles a day in 2010. Consequently the bridge has a sufficiency rating of 63.5 and is considered functionally obsolete.

This bridge is similar to the other bridges around Folsom with two column bents and mini-capitals at the tops of the columns. We can see how the bridge deck was slightly widened beyond the columns in the photo above.

Sacramento County, California Bridges: Greenback Lane Bridge across the American River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Figueroa Street Bridge across Riley Ravine

August 2013 (38.67694 Degrees, -121.17583 Degrees) Figueroa Street Bridge

There are several old bridges within a few miles of each other around Folsom, California. For the last two days we studied the Orangevale Bridge. Nearby is the Figueora Street Bridge (24C0269) that was built in 1916. It is a three span, continuous T girder bridge on two-column bents over Riley Ravine in Folsom. The ravine is quite steep and I had a hard time climbing down to photograph the substructure. The columns were cast with mini-capitals that reflect the neo-classical style of concrete bridges at the beginning of the 20th century.

The bridge includes open balustrade railing and a metal plate at the bridgehead giving the names of the people who built it (or who administered its construction).

The photo above shows how much lower the bridge is than its surroundings. I guess they didn't want to build it long enough to reach the top of the banks. The bridge is 90.9 ft long with a 40 ft center span over the river (but it looks longer in the top photo). The bridge is 18 ft wide, which is somewhat better than the previously studied Orangevale Bridge.

I don't know if Folsom has plans to replace this bridge, but I did notice it isn't eligible for historic status in the National Register. It's in generally satisfactory condition but they don't know about the foundation or if there is a scour issue.

Sacramento County, California Bridges: Figueroa Street Bridge across Riley Ravine by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Orangevale Bridge across Gold Creek (2)

August 2013 (38.68091 Degrees, -121.19427 Degrees) Orangevale Avenue Bridge

A few more photos of the Orangevale Bridge (24C0268). This bridge is 161 ft long with a 100 ft arch span and it's only 18 ft wide between the curbs. I guess that explains why the Lincoln Highway was eventually re-routed onto State Route 50. Still, the bridge carries a surprising 1000 vehicles a day!

On the map above we can see the Lincoln Highway originally jogged into Folsom and only later crossed the American River before finally settling on State Route 50 south of the river. It was in 1927 (when the highway crossed the American River) that the Orangevale Bridge briefly carried the Lincoln Highway.

Still, it is hard to understand how an 18 ft wide bridge could ever have carried two lanes of traffic. The Bridgehunter writes that the Lincoln Highway Association and the Heritage League of Folsom are planning to convert Orangevale Avenue to one-way traffic to try to preserve the bridge.

Sacramento County, California Bridges: Orangevale Bridge across the Gold Creek (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Orangevale Bridge across Gold Creek (1)

August 2013 (38.68091 Degrees, -121.19427 Degrees) Orangevale Avenue Bridge

New bridges are easier to photograph while older bridges are often surrounded by thickets of overgrown blackberries and poison oak.

According to the Bridgehunter, the Orangevale Avenue Bridge was once on the Lincoln Highway, which was the fastest route from New York to San Francisco. Later this bridge carried citrus from Orangevale and Citrus Heights to processing and shipping plants in Folsom.

This 98 year old bridge is about to get replaced by what the Bridgehunter calls a UCEB, an Ugly Concrete Eyesore Bridge.

I'm not in love the past. Still, this open spandrel arch bridge, with its nicely sculpted floor beams and barrier, is a nice reminder of the care that should be taken when building something to last 100 years.

Sacramento County, California Bridges: Orangevale Bridge across the Gold Creek (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (4)

March 2013 (38.49477 Degrees, -121.08421 Degrees) Cosumnes River Bridge

A few more photos of the Cosumnes River Footbridge. When I first saw this bridge from a distance, I just assumed I was looking at an old steel truss.

The bridge portals are unadorned vertical steel I girders with a Glulam top chord. The deck is 12 ft wide and composed of 2-1/2 inch thick Glulam panels. I'm not sure about the vertical clearance. The bridge had to be designed for a 10 kip maintenance vehicle. I wonder if it controlled the design?

A look at the underside of the bridge deck, which is supported by Glulam floor beams and stringers. Steel rods provide lateral stability at the top and bottom chords. The superstructure was designed by Western Wood Structures, the substructure was designed by Quincy Engineering, and the bridge was built by Viking Contractors. Western Wood Structures has a nice website with a description of this bridge.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (3)

March 2013 (38.49477 Degrees, -121.08421 Degrees) Cosumnes River Bridge

Another view of the Cosumnes River Footbridge, which was completed in 2008. The bowstring truss (and the parallel chord approach spans) are composed entirely of diagonal load bearing members. The only vertical elements are at the supports.

The trick to building timber structures is to provide well-designed connections. The steel plate connectors look like they were manufactured especially for this bridge. Also, the trusses use diagonal steel rods at the top and bottom chords instead of the usual sway bracing.

There are several websites that discuss this unusual structural including StructureMag which has some nice construction photos and the section properties of most of the bridge members.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (2)

March 2013 (38.49477 Degrees, -121.08421 Degrees) Cosumnes River Bridge

Another view of the Cosumnes River Footbridge. The exterior concrete is faced with rounded river stones. I wonder if they glued facing stones to the formwork or placed them after the concrete hardened?

The bridge is a nice combination of structural steel for the vertical members over the supports and the connecting hardware, glulam wood for the other truss elements, and stone faced reinforced concrete for the retaining walls, abutments, and piers.

What makes this bridge so impressive is that the glulam effortlessly bends upward to form the top chord of the bowstring truss. Talking to the residents at Rancho Murieta, they all expressed impatience at how long the bridge took to get built and satisfaction with how nice the finished product was.

Rancho Murieta is pleasant but slightly cultish because the relaxed lifestyle the residents enjoy is separated from the rest of the world. We'll take a closer look at their bridge tomorrow.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (1)

March 2013 (38.49477 Degrees, -121.08421 Degrees) Cosumnes River Bridge

The most interesting of the three bridges that cross the Cosumnes River in Rancho Murieta is this new timber bowstring truss pedestrian bridge.  I first saw it looking upstream from the State Route 16 Bridge, but I couldn't figure out how to get to it, since it's inside a gated community. I was thinking about kayaking down the Cosumnes River to photograph it when my wife suggested that we should just drive up to the entrance to Rancho Murieta and ask if we could photograph the bridge.

As I've often mentioned, truss bridges are seldom built nowadays, but this is a nice contemporary truss bridge and it looks especially nice in wood. The bridge was designed by Western Wood Structures and engineered by Quincy Engineering. Western Wood specializes in big, Glulam structures and Quincy Engineering is made up almost entirely of former Caltrans bridge engineers.

We'll take a closer look at this interesting bridge tomorrow.

Sacramento County, California Bridges: Rancho Murieta Footbridge across the Cosumnes River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: Cosumnes River Footbridge

April 2013 (38.49219 degrees, -121.09140 Degrees) The Yellow Bridge

Next to yesterday's State Route 16 Bridge is a pretty, yellow pedestrian truss bridge. The Cosumnes River Footbridge was built in 1908 and may have carried the Jackson Highway before the box girder bridge was built in 1952. This yellow bridge is a 227 ft long Pennsylvania Petit through truss with a Pratt truss approach span. According to Wikipedia, this type of truss bridge has "half-length struts or ties in the top, bottom, or both parts of the panels."

I did see some long ties at the bottom of the sway braces but I didn't see any half length struts or ties. Maybe they're talking about the long diagonal members that cross two panels. What I did notice about this and other Pennsylvania Petit trusses is that they are very long bridges with slightly rounded tops.

I wasn't able to walk on the deck of this bridge, because it was only for golfers who live in Rancho Murieta, which is a huge gated community.

Sacramento County, California Bridges: Cosumnes River Footbridge by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges: State Route 16 Bridge across the Cosumnes River

April 2013 (38.49163 Degrees, -121.09161 Degrees) State Route 16 Bridge

Continuing north on Ione Road and west on the Jackson Highway (State Route 16) we came to three interesting bridges in Rancho Murieta. The first bridge carries the highway over the Cosumnes River. The State Route 16 Bridge (24 0080) is a three span continuous, cast-in-place box girder bridge. It is 255 ft long with a 134 ft long center span that was built in 1952.

I think they must have added a sidewalk (supported by steel braces) on the north side of the bridge in the 1980s. At that time, the bridge must have picked up a lot more traffic and needed to get pedestrians off the road. The bridge width is 26 ft curb to curb but it's 37.4 ft from edge of deck to edge of deck.
The bridge is supported on pier walls on each side of the Cosumnes River.

Sacramento County, California Bridges: State Route 16 Bridge across the Cosumnes River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Sacramento County, California Bridges; Ione Road Bridge across Willow Creek

April 2013 (38.41583 Degrees, -121.03889 Degrees) Ione Road Bridge

Today we'll begin exploring the bridges in southern Sacramento County. Crossing the line from Amador into Sacramento County on Ione Road we came to a bridge over Willow Creek.

The Ione Road Bridge (24C0330) is a three span reinforced concrete slab bridge that was built in 1950. It replaced an older bridge that crossed Willow Creek a little east of the current bridge. They must have built the new bridge to the west, realigned the road, and then tore down the old bridge. The abutments of the old bridge were left in place.

Sacramento County, California Bridges; Ione Road Bridge across Willow Creek by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Seventh Street Bridge across the Los Angeles River

August 2013 (34.03444 Degrees, -118.22639 Degrees) Seventh Street Bridge

South of the Sixth Street Bridge is the Seventh Street Bridge.  We last looked at the Seventh Street Bridge (and the other LA River Bridges) in 2009. At that time we mentioned how the bottom deck was built for trolleys in 1910. In the 1920s they simply built a top deck above the abandoned bottom deck, which had become lower than the top of the riverbank. Although the bottom deck isn't used for traffic, it appears to be a shelter for homeless people that congregate around this part of town. Note the big cutwaters on the upstream side of the piers.

Like most of the other bridges across the L.A. River, the Seventh Street Bridge (53C1321) was seismically retrofitted in the 1990s, despite having a deck rating of 'Poor.' The bridge is 1000 ft long with three 90 ft long deck arch spans over the river.

Los Angeles County, California Bridges: Seventh Street Bridge across the Los Angeles River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Fourth Street Bridge across the Los Angeles River (2)

August 2013 (34.04167 Degrees, -118.22694 Degrees) 4th Street Bridge

Another perspective of the Fourth Street Bridge surrounded by the buildings of downtown L.A.. The buildings were built over time in a variety of styles. In the foreground are warehouses, some of which will have to be relocated for the Sixth Street Bridge replacement project. In the background is downtown Los Angeles with 1930s style Art Deco skyscrapers (on the right) and modern steel and glass towers (on the left).

Los Angeles County, California Bridges: Fourth Street Bridge across the Los Angeles River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Fourth Street Bridge across the Los Angeles River (1)

August 2013 (34.04167 Degrees, -118.22694 Degrees) 4th Street Bridge

Standing on the deck of the Sixth Street Bridge and looking north at the Fourth Street Bridge. It's a nice, clear day (for Los Angeles) and we can see the Verdugo Mountains in the background.

The Fourth Street Bridge is a long viaduct that was built in 1930 and crosses the same obstacles as the Sixth Street Bridge. However, the Fourth Street Bridge has an open spandrel concrete arch over the L.A. River and it was seismically retrofit in 1995. Even after the retrofit though, it remains structurally deficient and with a deck in 'Poor' condition. A question that bridge owners need to address is if it makes economic sense to retrofit a bridge in poor condition?

Los Angeles County, California Bridges: Fourth Street Bridge across the Los Angeles River (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (4)

August 2013 (34.03722 Degrees, -118.23038 Degrees) 6th Street Bridge

The Sixth Street Bridge (53C1880) was built in 1932 across the Los Angeles River in Downtown L.A. It's an iconic structure and like many of the other Los Angeles River Bridges it's been used in many films. In fact, the campaign to replace the 6th Street Bridge with a new iconic structure is being promoted in YouTube videos with the mayor of Los Angeles and even the Friends of the Los Angeles River. The bridge is in a depressed area of Los Angeles and the hope is that a user friendly, happy-looking bridge will help turn the area from an industrial wasteland into a green parkway full of strolling families and picnickers.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (3)

August 2013 (34.03722 Degrees, -118.23038 Degrees) 6th Street Bridge

A photo of the two steel arch spans of the Sixth Street Viaduct across the Los Angeles River. I was surprised that there was a large pedestrian undercrosssing that could potentially allow someone to drive their car onto the concrete-lined river. Perhaps that's how they bring cars into the river in the movies?

Note how the arch ribs look strange due to the skew of the bridge in relation to the river. Because of the angle, the piers pick up the arch lower on one side because they are closer. Also note how a homeless person has set up a home in one of the pipes that empties into the river.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (2)

August 2013 (34.03722 Degrees, -118.23038 Degrees) 6th Street Bridge

We last studied the Sixth Street Bridge when we were looking at Los Angeles River Arch Bridges in 2009. Last week's field review was partially to identify the many utilities, private residences, warehouses, etc. that would have to be removed to build the new bridge and what heavy equipment could access the site during construction.

From the west, the current access to the bridge is through a narrow PUC under the railroad yard. Working with railroads during construction can be difficult. In the photo below, we see the Fourth Street Bridge from the deck of the Sixth Street Bridge. We can also see transmission lines, the Los Angeles River, and a dozen railroad tracks that will have to be somehow avoided during construction.

Los Angeles County, California Bridges: Sixth Street Bridge across the Los Angeles River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.