Alameda County, California Bridges: Hegenberger Road OH across the UPRR (2)

April 1996 (37.75278 Degrees, -122.19583 Degrees) Hegenberger Road OH

The Hegenberger Road Overhead (33C0202) is a five span continuous prestressed concrete T girder bridge, which was built in 1966. It's owned by Alameda County and it goes over the Bay Area Rapid Transit (BART), the Union Pacific Railroad (UPRR), and San Leandro Road. It's 900 ft long with a 290 ft span over BART. It also crosses over an automated rail system to the Oakland Airport and it's next to Oakland Coliseum, which is where the Oakland Athletics play baseball.

I really liked this bridge. I was impressed by how the contractor achieved such a nice striated texture on the concrete and how the different concrete faces catch the light. The shapes of the columns are unusual and make the bridge interesting. An unusual pinned connection was created between the top of the squat columns and the different bent caps.

I took today's photos many years ago with a film camera. When I returned to this bridge last week (for the current series of blogs on the bridges of Alameda County) I was disappointed to find the bridge was undergoing refurbishment (see yesterday's blog). 

After looking on the Internet, I discovereded that the bridge is currently being seismically retrofit. However, it's unfortunate that the designer couldn't find a way to improve the seismic performance without ruining the appearance of this handsome bridge.

Alameda County, California Bridges: Hegenberger Road OH across the UPRR (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Alameda County, California Bridges: Hegenberger Road OH across the UPRR (1)

June 2014 (37.75175 Degrees, -122.19605 Degrees) Hegenberger Road Overhead

Southeast of Alameda Island was a very handsome bridge designed by TY Lin. The Hegenberger Road Overhead celebrates the ability of concrete to take on a myriad of shapes while floating effortlessly in the air (see photo above). Unfortunately, it appears that some rehabilitation work on the bridge has made it far less attractive (see photo below).

Alameda County, California Bridges: Hegenberger Road OH across the UPRR (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Alameda County, California Bridges: Posey and Webster Street Tubes across the Oakland Estuary

June 2014 (37.79124 Degrees, -122.27578 Degrees) Posey and Webster Street Tubes

Before we leave Alameda Island I wanted to mention the last two crossings from the mainland. However, these structures are tubes that go under the Oakland Estuary. From 1871 until 1928 the Webster Street Crossing (a swing bridge) connected Oakland to Alameda Island at this site.

In 1923 the Alaska Packers Association promised to build wharves and warehouses on Alameda Island if a tube was built. $4.5 million was allocated and the Posey Tube (after County Surveyor George Posey) was constructed from 1925 to 1928. Precast concrete tubes were built in San Francisco, floated to the estuary, sunk into a trench, sealed together, and then covered in Bay Mud. In 1963, a second tube (the Webster Street Tube) was built.

The tubes performed pretty well until the 1989 Loma Prieta Earthquake shook the estuary. The tubes were sitting in unconsolidated mud and tried to rise to the surface, allowing water to leak into the joints. A long, costly retrofit was performed in the 1990s, which should protect the public but it may not prevent the tubes from being damaged and closed after the earthquake.

Alameda County, California Bridges: Posey and Webster Street Tubes across the Oakland Estuary by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.