Bridges of Canada; Northumberland Strait (Confederation) Bridge

Northumberland Strait Bridge

Writing last week about the Strait of Kerch Bridge reminded me of the Northumberland Strait (Confederation) Bridge. The Strait of Kerch Bridge is 19 km long and will cost about $4 billion. The Strait of Northumberland Bridge is 12.9 km long and cost about $1 billion. The Kerch Bridge connects the Russian Federation to Crimea and the Northumberland Bridge connects the Canadian mainland to Prince Edward Island.

But what made me think of the Northumberland Strait Bridge in relation to the Kerch Strait Bridge is that they both must resist ice floes during the winter. In fact, the Northumberland Strait Bridge was specially designed to break up the ice floes while resisting their force. In the photo below we can see the ice being broken up as it moves past the bridge pier.

In the next photo we can see the bell-shaped ice shield with steel plates to protect it from the ice floes. The shape of the shield forces the ice to move upward so that it breaks into pieces and flows around the pier. In this photo a research team is visiting the pier to measure the thickness of the ice.

Most of the photos, drawings, and information for this article came from the well-written 'Bridging the Strait' by Copthorne MacDonald. We can see in his drawing (shown below) that the ice shield is built at the water's surface (while the bottom of the pier may be 100 ft below).

The superstructure is composed of match-cast single box girder segments and drop-in spans. The bridge was designed by Jean Muller International and checked by Buckland and Taylor. A navigational span was built to allow ships to pass under the bridge. The bridge was completed in 1996 and has resisted the ice floes for over 20 years. Hopefully, the Kerch Strait Bridge will have a similar record of accomplishment.

Russian Federation Bridges: Bridges across the Strait of Kerch

Strait of Kerch Bridge

Bridge building is a political act that confers considerable power to the bridge owner. I was reading in this week's New Yorker that Vladimir Putin is building a bridge across the Kerch Strait (between Russia and Crimea) to increase the Russian Federation's power over it's newly conquered peninsula.

This is not the first attempt to build a bridge across the Strait of Kerch. When the British Empire was still expanding, an attempt was made to build a bridge from England to India across the Strait of Kerch, but it was determined to be too expensive. Russia's first attempt to build the bridge was at the beginning of the 20th century before the revolution put an end to their plans. The Russians got another chance at the end of WWII but the bridge was soon destroyed by ice floes across the Strait.

The latest attempt to build the Kerch Strait Bridge began in May of 2015. The projected budget is $4 billion (228 billion rubles). The alignment crosses Tusla Island to reduce the amount of bridge that is required (see above map). Construction of the bridge was awarded to Arkady Rotenberg's SGM Group who also built the facilities for the 2014 Sochi, Winter Olympics. That project had huge cost over-runs, which is apparently part of doing business in Russia.

Rotenberg is Putin's childhood friend. Putin apparently only trusts his friends to run Russian industries. According to the New Yorker article, the Russian economy is a form of feudalism where all the chiefs of industry are one step away from the seat of power.

Actually, it looks like two bridges are being constructed, a four lane roadway bridge and a parallel two track railway bridge. The bridges will have three segments, from Taman Peninsula to Tusla Split is 7 km, from the Split to Tusla Island is 6.5 km, and continuing to Crimea is another 5.5 km for 19 km total.

Large diameter steel pipe piles were driven into the sea bed and two column bents were cast on top. Big steel truss superstructure spans were built on land, carried to their location by barge, and lifted onto the bents. What bothers me from looking at the top photo is that there are no bent caps or lateral bracing between the columns to provide lateral strength and resistance to the structure. Hopefully, they are going to be built later. A pair of steel arch spans will eventually be built over the shipping channel, as shown in the computer generated image below.

The bridge is supposed to open at the end of 2018 and be fully operational by June 2019. Trestle bridges were constructed at both ends to move material and as a base for pile driving. It was reported that 200 WWII era bombs were found while the site was being prepared for construction. The photo below (showing the pile driving off of the trestle structure) was taken with a drone operated camera by the Russian News Service, RUPTLY. Several excellent videos and other information can be found on the Internet, unfortunately mostly in Russian.

There is considerable conjecture about whether the bridges will be completed on time and at cost. My feeling is that Rotenberg will do whatever it takes to keep his boss happy.

California's Bridges: Recent Books about the East Bay Bridge across San Francisco Bay

Books on the New East Bay Bridge

After the Loma Prieta Earthquake in 1989 caused damage to the San Francisco - Oakland Bay Bridge, Caltrans engineers spent many months analyzing the structure before coming to the conclusion that the West Bay Crossing (a suspension bridge) could be retrofitted but the East Bay Crossing (a long steel truss bridge) needed to be replaced. The decision to retrofit or replace a seismically vulnerable structure, repeated countless times during the big retrofit program in the 1990s, only resulted in controversy on the East Bay Crossing Project.

Two recent books shed light on this project.  'Bay Bridge, History and Design of a New Icon' was written by an architect involved in the project (Donald MacDonald) with help from the writer Ira Nadel.  'Remaking the San Francisco - Oakland Bay Bridge' was written by an adjunct professor at the University of California at Berkeley in Transportation Planning (Karen Trapenberg Frick) who explores the rebuilding of the bridge as a 'MegaProject,' a strange creature that needs to be better understood.

Caltrans engineers tried to make reasonable decisions for the design of this bridge but everything was amplified by the many people and groups who had an interest in the project.  There were professors and consultants eager to have their ideas considered, government agencies moving the project in different directions, politicians trying to make the project benefit their constituents, and reporters looking for a big story.

The original plan was to build a simple skyway, two miles of prestressed concrete box girder spans that provided a seismically safe structure to resist the next big earthquake (see figure above by MacDonald for his book). However, all of the different groups were pushing for a signature span for this important structure. Perhaps if Caltrans had been allowed to build their 'plain vanilla' bridge, billions of dollars could have been saved.

Readers interested in studying how big bridge projects can take on a life of their own are encouraged to read these interesting books.