Los Angeles County, California Bridges: E105-N110 HOV Connector OC

April 2015 (33.9292 Degrees, -118.2818 Degrees) E105-N110 HOV Connector OC

The next day, I got a ride from a professor back onto the Harbor Freeway and then west onto the Century Freeway to the airport. He was driving a Volt and said the 40 mile battery was just enough to get him back and forth from his house at Hermosa Beach.  Also, it allowed him to use the HOV Connector (53 2682E) that we had climbed onto to avoid the heavy traffic.

This complicated interchange was another project that I worked on in the 1980s. It was so densely packed that we had trouble finding room to put our columns, some of which were 150 ft high with big outrigger bent caps. I designed some of the smaller connectors but I had to use C-bents to step around the bridges and roads.

Los Angeles County, California Bridges: E105-N110 HOV Connector OC by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Alameda County, California Bridges: The Stack in Oakland

June 2014 (37.82433 Degrees, 122.26828 Degrees) The Oakland Stack

Just south of the University Ave POC the highway splits into traffic going over the Bay Bridge (on I-80) and traffic going into Oakland (on I-580). There are quite a few big interchanges in the area, including the MacArthur Maze and the Oakland Stack (shown above). Note the cased columns (painted white), which were part of an elaborate seismic retrofit. Readers wishing more information on this interchange can look at a series of blogs I wrote in 2010.

Alameda County, California Bridges: The Stack in Oakland by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Contra Costa County, California Bridges: 680/24 Interchange in Walnut Creek

February 2014 (37.8963 Degrees, -122.0734 Degrees) 680/24 Interchange

Just east of EL Curtola OC is the 680/24 Interchange with connectors, separators, overcrossings, and undercrossings all climbing over each other. Many of my friends worked on this interchange in the 1990s as part of Caltrans engineer rotation program.

These photos hardly do justice to the many soaring bridges in this interchange (I was too nervous to stop in the middle of the expressway to take a photo). Most of the bridges are cast in place prestressed concrete structures, but there was a temporary steel girder bridge that sat on isolation bearings for several years and then was picked up at the end of the project and placed on its new substructure.

The interchange (and El Curtola OC) can be seen in the Google earth photo shown above (the blue lines are a few of the many earthquake faults in the area. The urban area east of the Interchange is the affluent city of Walnut Creek which we will be exploring over the next few days. 

Contra Costa County, California Bridges: 680/24 Interchange in Walnut Creek by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Broward County, Florida Bridges: I-75/I-95/I-595 Interchange

January 2014 (26.08234, -80.1687 Degrees) I-95/I-75/I-595 Interchange

The cities in south Florida cling to the east coast to avoid the enormous wet grasslands (see Google earth photo below). The main east-west highway through this densely populated sliver of land is I-95. Driving back and forth along I-95, the bridges I observed were mostly connectors and overcrossings (see photo above).

These bridges are composed of steel or precast concrete girder simple spans tied together with a concrete deck and sitting on single or multi-column bents. Again, not particularly attractive but they get the job done.

However, while driving by the Fort Lauderdale airport I saw the big I-95/I-595/I-75 interchange with each connector painted a different color. I couldn't get much of a photo in the gathering darkness, but looking at Google earth in 'Street View' I was able to find a nice picture of this structurally uninspiring but delightfully colored interchange.

Broward County, Florida Bridges: I-75/I-95/I-595 Interchange by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Osaka Prefecture, Japan's Bridges; Matsubara Interchange

November 2013 (34.6000 Degrees, 135.46212 Degrees) Yamatogawa Expressway

After visiting the Higashi-Kobe Bridge we drove east to the Matsubara Interchange on the Yamatogawa Expressway Project. This part of Osaka has become so congested that they are building a ring road to relieve the gridlock (see map below). The Yamatogawa Route is a 9.7 km expressway linking the Hanshin Expressway Route 4 (Wangan Route) and the Matsubara Route 14. It was originally planned to built the Yamatogawa Route as a cut and cover tunnel but because of the many obstacles like railroad tracks, water treatment plants, etc., it was eventually decided to make it a shield tunnel except for the ramp connectors. Also, some culvert-like tunnels are being constructed using an underground launching procedure. 

Work on this project began in 1999 and it's still continuing. The work is complicated by the Uemachi and several other faults that go under the tunnels and bridges. They said they were designing the structures for the resulting ground shaking, but I'm not sure if they were designed for the resulting fault offset.

In the photo above we can see part of the interchange as well as the Yamatogawa (Cable-Stayed) Bridge in the background that we studied in 2009. Somehow, there's even room for an incinerator. Note the large catchment basin in the middle of the interchange. They said the basin is going to remain after the interchange is complete, perhaps for drainage. Holding the megaphone is our very patient interpreter, Iva carrying her megaphone. Note that they gave us white gloves and hardhats to wear at every construction site.

Osaka Prefecture, Japan's Bridges; Matsubara Interchange by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Sanriku Expressway Interchange in Miyagi Prefecture

June 2011 (38.3027 Degrees, 140.9812 Degrees) Sanriku Expressway Interchange

A photo looking north at the Sanriku Expressway just before it splits into the Sendai Hokubu Road going northwest and the Sanriku Expressway going northeast. We are leaving the Sendai Plains and will be climbing into the coastal mountains where the most severe tsunami damage occurred. 

Japan's Bridges: Sanriku Expressway Interchange in Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

Japan's Bridges: Construction of Sendai Tobu Interchange, Miyagi Prefecture

June 11, 2011 (38.3695 Degrees, 140.9756 Degrees) 

Just north of the Nanakitagawa in the Miyagino Ward is a project to build a new interchange on the Sendai Tobu Toll Road. The Japanese economy must be so strong that in the middle of recovering of a tsunami they can continue building new infrastructure. I wonder what that massive concrete wall is for?

Japan's Bridges: Construction of Sendai Tobu Interchange, Miyagi Prefecture by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.