Los Angeles County, California Bridges: Owensmouth and Canoga Avenue Bridges across the Los Angeles River

August 2009 (34.1951 Degrees, -118.6014 Degrees) Los Angeles River Bridges

London has the Thames and Paris has the Seine, but Los Angeles (an equally important city) has the Los Angeles River. The LA River is a 48 miles long (mostly concrete lined) channel that flows from Canoga Park (in the Valley) to the Pacific Ocean (in Long Beach). We'll spend the next few weeks studying some of the bridges (and the different neighborhoods) that the river passes through.

The source of the river is where Bell Creek and Arroyo Calabasas come together at Canoga Park High School (see photos above and below)). After it's creation, the river immediately flows under the Owensmouth Avenue Bridge, a single span precast girder bridge and the Canoga Avenue Bridges, which are two span precast girder bridges. The bridges will get more interesting as we continue downstream.

The river usually has some water flowing all year long. Actually, the river can't carry all the water during heavy rains due to all the surrounding development. At this location we are in the suburbs of the San Fernando Valley, which is somewhat monotonous but still has charm due to the tropical vegetation and the nicely landscaped yards and gardens.

Los Angeles County, California Bridges: Owensmouth and Canoga Avenue Bridges across the Los Angeles River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Miami-Dade County, Florida Bridges: Julia Tuttle Causeway across Biscayne Bay

January 2014 (25.81028 Degrees, -80.15028 Degrees) Julia Tuttle Causeway

The Julia Tuttle Causeway carries State Route 195 across Biscayne Bay. It includes a highway on a human-made island in the middle of the bay and bridges at the two ends. The western bridge (FDOT #870301) is 2120 ft long with steel girder spans. The eastern bridge (FDOT #870302) is 1138 ft long with precast girders on parallel two column bents (shown below). Both bridges were built in 1959 and widened in 1990/1991.

Julia Tuttle is considered to be the founder of Miami. At the end of the 19th century she owned a large portion of the land in the area and successfully promoted it for development. The Julia Tuttle Causeway became famous because for several years the island was the only place that sexual offenders released from prison in Miami-Dade County were allowed to live. 

Miami-Dade County, Florida Bridges: Julia Tuttle Causeway across Biscayne Bay by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (6)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

They were able to make the Hasaki Bridge continuous over several spans by extending the reinforcement at the ends of the precast girders and casting diaphragms at the bents (there's an expansion joint at the end of the third span).

I wonder if the damage during the 2007 Kashiwazaki Earthquake was due to the increased mass of the continuous three span superstructure banging into the abutment backwall? Although the damage was just some cracks at the ends of the girders, it required considerable effort to repair.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (6) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (5)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

A photo looking up at the Hasaki Bridges. I mentioned in a previous post how we tried walking to the piers to see if there was any damage at the bottom but the vegetation was so dense, we couldn't get close to them.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (5) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (4)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

A view from the closed northbound deck (while driving south) of the Hasaki Bridge just before the tunnel through the Yoneyama Mountains with the Sea of Japan in the background.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (4) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (3)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

Another view of the Hasaki Bridges carrying the Hokuriki Expressway through the Yoneyama Valley. The northbound bridge had some abutment damage during the 2007 Kashiwazaki Earthquake. When we visited the bridge, they had driven sheet piles to hold back the embackment and were pouring a concrete pad to support the girders  while they made repairs.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (3) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (2)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

After the earthquake, the Hokuriku Expressway was jammed with traffic, which prevented emergency vehicles from reaching the damaged area and also slowed repairs to reopen parts of the expressway.  Although the Hokuriku Expressway is a privately owned toll road, it was opened to the public to help during the emergency.  There were at least 17 locations where damage was severe enough to close parts of the expressway (see figure below).  There was damage to bridges, tunnels, roads, and to other highway facilities. The damage extended from 338 KP to 416 KP, for a distance of about 78 km.

During the earthquake the embankments on the Hasaki Bridges moved downhill, exposing the wingwalls. The concrete spalled at the bottoms of the girders due to the abutment banging against them  (the bridges are 29 km from the epicenter but closer to the fault rupture). The spall occurred about 0.6m from the abutment backwall and on the other side of the bearing. Apparently, as the girders went into compression, this was the location of maximum negative moment.  The damage occurred at the north end of the west bridge (small cracks were observed on the east bridge).

When we arrived at the scene, both directions of traffic had been diverted to the east bridge, they had finished driving sheet piles around the abutment to stabilize the soil, and were casting a large pad at the west bridge so that they could jack up the southern three spans and repair the girders and bearings.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (1)

August 2007 (37.315 Degrees, 138.437 Degrees) Hasaki Bridges

The Hasaki Bridges go between two tunnels on the Hokuriki Expressway. They are parallel five-span concrete ‘I’ girder bridges on seat-type abutments and tall pier walls.  The three northern spans are continuous over steel bearings with an expansion joint at the end of the third span. The piers are on piles except where there is rock near the surface.  The bridges are just north of the Yoneyama tunnels (shown in the photo), which were damaged by the 2007 Kashiwazaki Earthquake. The bridges were also damaged. We went under the bridges to look at the bottom of the piers but the undergrowth was so thick we couldn’t get close to them. We'll take another look at these bridges tomorrow.

Niigata, Japan's Bridges; Hasaki Bridges on the Hokuriki Expressway (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.