Monthly Archives: September 2013

The Bold and the Beautiful: The San Francisco-Oakland Bay Bridge East Span Opens to Traffic

 

The self-anchored suspension tower as seen from the original East Span. (Photo courtesy of Tom Paiva/BATA)

The self-anchored suspension tower as seen from the original Bay Bridge East Span.
(Photo courtesy of Tom Paiva/BATA)

The San Francisco Bay area has another impressive icon to add to its skyline. The East Span of the San Francisco-Oakland Bay Bridge officially opened to traffic  Labor Day weekend. After 11 years of around-the-clock construction, the previous cantilever portion of the bridge has been replaced with a new self- anchored suspension bridge and two parallel roadways with five lanes in each direction. At 2,047 feet long with a single 525-foot tall tower, the East Span’s self-anchored suspension bridge is the world’s largest. The bold beauty of the self-anchored suspension bridge’s graceful asymmetric design is not only aesthetically pleasing, it can absorb most of the shock from an earthquake to prevent damage to the main structure.

The original San Francisco-Oakland Bay Bridge was damaged in the 1989 Loma Prieta earthquake. While the bridge was repaired and opened to traffic one month later, it was determined that the best solution in the long-term would be to retrofit the West Span and replace the East Span.

Opening the bridge to traffic, complete with a traditional chain-cutting ceremony to mark the milestone, seemed fitting for Labor Day weekend after the decades of design and construction work done on the six seismic safety projects that make up the bridge. While traffic is now flowing there is still some work left to do before all components of the new and improved bridge, including a pedestrian and bike path, are in place.

State and local officials join California Lt. Governor Gavin Newsom to open the East Span by  re-enacting the chain cutting that marked the opening of the original Bay Bridge in 1936. (Photo courtesy of Caltrans)

State and local officials join California Lt. Governor Gavin Newsom to open the East Span by re-enacting the chain cutting that marked the opening of the original Bay Bridge in 1936.
(Photo courtesy of Caltrans)

As Collaborative Services continues its celebration of Labor Day all month long through our exploration of BIG projects we could think of no better BIG project to feature than one that’s opening coincided with the holiday. We talked to San Francisco-Oakland Bay Bridge spokesperson, Andrew Gordon  to learn about the challenges the project faced along the way, the bridge’s unique design, how the public was kept informed, and what work is left to be completed.

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Like many large public works projects the San Francisco-Oakland Bay Bridge has found itself tied up in political battles, cost overruns, and engineering challenges. How did the project overcome these challenges and stay the course?
Building the new East Span has been a monumental endeavor, in terms of both the hurdles we have overcome and the feats that we have accomplished. The new East Span has been in the works since the 1989 Loma Prieta earthquake, when a 250-ton section of the original East Span’s upper deck collapsed, killing one motorist. Since then, the new bridge has been subjected to political battles, cost increases due to design changes and material cost, and unforeseen construction challenges. The project has overcome adversity by never forgetting the job at hand – building a structure that carries Bay Area traffic safely.

A diagram of the San Francisco-Oakland Bay Bridge Seismic Safety Safety Projects. (Credit: The San Francisco Citizen)

A diagram of the San Francisco-Oakland Bay Bridge Seismic Safety Safety Projects.
(Credit: The San Francisco Citizen)

In July 2005, the Toll Bridge Program Oversight Committee, consisting of the California Department of Transportation, the California Transportation Commission and the Bay Area Toll Authority was formed to oversee the Toll Bridge Program, and to improve accountability and ensure openness.  Since the creation of this committee, the project has remained on-budget and on-schedule.

After 32 bolts broke on one of the bridge piers in March, we rose to the challenge by bringing the best and brightest engineers and designers together with an outside panel of experts and the Federal Highway Administration. This combination of internal and external collaboration ensured that our retrofit solution was the best possible.

Contractors, engineers, consultants, renowned experts and architects have worked together to push the limits of design and engineering to create one of the most seismically advanced structures in the world.

At 2,047 feet long, the new east span is the largest self-anchored suspension bridge structure in the world. Why was a self-anchored suspension design chosen for this bridge?
Discussion about the new bridge design began in 1997, when Bay Area elected officials and the public decided they wanted a bridge that was both seismically sound and aesthetically appealing.  In March of 1997 the Metropolitan Transportation Commission appointed the Bay Bridge Design Task Force to forge a regional consensus on the design of the new East Span. A single-tower self-anchored suspension (SAS) bridge design with a pedestrian and bike path on the south side was eventually selected in 1998. This design was chosen for a variety of factors. Architecturally, it reflects the Bay Area’s strong tradition of suspension bridges, including the Golden Gate, Bay Bridge West Span and Carquinez Bridge. It also corresponds with the geologic constraints of the region. The tower foundations sit deep within the last remaining portion of bedrock before the Oakland shoreline, providing structural stability as well as a dynamic, asymmetric appearance.  The Self-Anchored Suspension span has been designed to be aesthetically unique as well as functional— an iconic landmark capable of withstanding a major earthquake.

State of the art LED lights illuminate the self-anchored suspension span. (Credit: Tom Paiva/BATA)

State of the art LED lights illuminate the self-anchored suspension span.
(Photo courtesy of Tom Paiva/BATA)

The bridge’s new east span was designed and constructed to withstand the strongest possible earthquake that may occur within the next 1,500 year period. What are some of the cutting-edge innovations and enhancements that were used to achieve this?
The new bridge was designed to meet the most stringent earthquake standards and to act as a regional lifeline structure, opening to traffic within a day or two after the strongest ground motions expected in a 1,500-year period. Since 2002, the design, engineering and construction teams have met the challenge of making the new East Span seismically resilient with groundbreaking technology and enhancements – some never before used in bridge building – that have transformed the bridge into a state-of-the-art engineering marvel.

Numerous innovations help make the bridge secure, yet flexible enough to withstand the greatest seismic forces. The Skyway’s concrete deck sections sit on 160 rebar and concrete steel piles driven at an angle up to 300 feet below the water’s surface, through a process called “battering.” While this method has been used to secure foundations for oil rigs, this is the first time it has been used for bridge construction. The hinge pipe beams that sit between the roadway sections act like giant shock absorbers, designed to move within their sleeves during expansion or contraction of the road decks during minor events. They are also designed to absorb the energy of an earthquake by deforming in their middle or “fuse” section, which will minimize damage to the bridge’s main structure. The single, 525-foot tall tower is made up of four separate pentagonal legs connected by shear link beams. These beams allow the legs to move independently, and are designed to protect the tower from catastrophic damage by absorbing seismic energy during an earthquake.

Much of the construction work done on this project was done during live traffic. What were some of the challenges this created and what unique approaches were used to ensure the safety of the traveling public and crew members during demolition and construction?
The bulk of construction work was done next to live traffic so there was little interference with the traffic flow on the original Bay Bridge.

During Labor Day Weekend 2009, crews faced the challenge of building the Yerba Buena Island Transition structure without disrupting the flow of traffic into the Yerba Buena Island Tunnel. To accomplish this daunting task, eastbound and westbound traffic were shifted off the original roadway onto a temporary detour. The new detour sat just south of the roadway, and allowed the contractor to demolish the original westbound approach to the tunnel and continue construction on the new transition structure.

Over Memorial Day weekend in 2011 and President’s Day weekend in 2012, crews realigned traffic lanes and built detours west of the Toll Plaza, allowing engineers and construction crews to complete the last eastbound section of the Oakland Touchdown sooner than expected. This detour allowed east and westbound traffic to start traveling on the new East Span at the same time.

The Oakland Touchdown portion of the San Francisco-Oakland Bay Bridge. (Credit: The San Francisco-Oakland Bay Bridge Seismic Safety Projects)

The Oakland Touchdown portion of the San Francisco-Oakland Bay Bridge.
(Photo courtesy of Caltrans)

What type of public involvement efforts were done throughout the project and how was the public kept informed during construction?
The new East Span of the San Francisco-Oakland Bay Bridge has always been a source of public intrigue. When crews broke ground on the East Span in 2002, highly visible, large-scale construction endeavors began to capture the attention of the over 280,000 motorists who crossed the original span each day. As the Bay Bridge continued to grow and take shape, so too did public interest.

A Public Information Office (PIO) was established in 2005 by the Toll Bridge Program Oversight Committee with the goal of maintaining positive relationships, communication and outreach with the public and stakeholders to ensure smooth project implementation. The PIO serves as the nexus point for day-to-day communication and information for all stakeholders interested in the Bay Bridge.

The PIO facilitates weekly on-and off-site stakeholder tours, coordinates daily with local and regional media and supports third party documentary efforts from groups such as National Geographic, Discovery Channel and the BBC. Community relations have been at the heart of outreach efforts for the Bay Bridge, beginning with work done on the West Approach retrofit in San Francisco. The Community Relations team develops and implements a tailored outreach plan based on the varied constituencies and needs of the East Bay and San Francisco communities.

Our website, BayBridgeInfo.org, acts as a central hub for information about the project. Collateral materials, construction updates, lane closures and project photographs are all available to inform the public about significant impacts and project milestones. Social media has also become a fundamental outlet for us to disseminate information. We have developed unique content to inform our Facebook and Twitter users, and to drive traffic to our website.

The East Span of the bridge opened to the public this past Labor Day weekend and traffic is now flowing. What work is left to do to complete the project?

An inaugural procession of vehicles across the new bridge was part of the bridge's grand opening event.  (Credit: The San Francisco-Oakland Bay Bridge Seismic Safety Projects)

An inaugural procession of vehicles across the new bridge was part of the bridge’s grand opening event.
(Credit: The San Francisco-Oakland Bay Bridge Seismic Safety Projects)

As soon as traffic was moved to the new East Span, crews began preliminary work to demolish the original span. Complete demolition will be divided into several parts: the cantilever/truss section, smaller truss sections, the S-curve and the foundations. The demolition process is expected to take about three years.

Work also remains on the bike and pedestrian path. Before the pathway can fully connect to Yerba Buena and Treasure Islands, crews will need to demolish a portion of the existing bridge that sits in the way of the new bike and pedestrian path in order to build and connect the rest of the path to Yerba Buena Island. The contractor will also construct a permanent connector to replace the temporary pathway from Oakland.

In August, crews successfully installed the temporary steel shims that allowed the bridge to achieve the seismic safety necessary to open to traffic. However, fabricators continue to work on the permanent steel saddle fix. The custom steel saddle system is designed to replace 32 broken bolts, providing an equal clamping force that will hold down seismic devices during an earthquake. The saddles are scheduled to be complete by December.

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We look forward to crossing the new San Francisco-Oakland Bay Bridge one day whether by foot, bike, or motor vehicle. Best of the luck with the demolition and remaining work!

Liz Faris, Account Manager
Collaborative Services, Inc.

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Meet Bertha: Seattle’s 7,000 ton solution to a decade of debate.

A view of the current State Route 99 Alaskan Way Viaduct double-deck highway through downtown, which will be replaced with a bored tunnel. (Credit: Washington State Department of Transportation)

A view of State Route 99 Alaskan Way Viaduct double-deck highway through downtown, which will be replaced with a bored tunnel.
(Credit: Washington State Department of Transportation)

In 2001, an earthquake rocked Seattle for a terrifying 45-second span, causing hundreds of injuries and $1 billion to $4 billion in damage. One structure that withstood the earthquake was the Alaskan Way Viaduct. While still standing, this double-deck highway that runs through the city’s downtown had sunk several inches and would have likely collapsed if the earthquake had continued any longer. While crews were able to stabilize the structure, it was ultimately deemed that replacement of the viaduct was the best course of action. What followed, for nearly a decade, were the aftershocks of public discourse and political debate  to determine the best replacement option. This led to one of the most scrutinized public participation processes in the state’s history, including more than 90 alternative options for the viaduct’s replacement. By 2009, advancements in technology made the best option for the viaduct’s waterfront section clear – a bored tunnel. This option was the only alternative that would allow the busy State Route 99 to remain open during the majority of construction and maintain a connection to and through the city’s downtown.

Fast-forward to today and the project is now home to the world’s largest-diameter tunneling machine, named Bertha after Seattle’s first female mayor. Weighing in at 7,000 tons, Bertha is charged with digging a tunnel beneath downtown Seattle. She began her work in July and once the digging is complete the viaduct will be demolished and replaced with a new tunnel to carry traffic along this bustling portion of State Route 99. The Washington State Department of Transportation (WSDOT) has made it easy for the public to track Bertha’s progress by allowing people to follow her journey online or via social media. Bertha has her own Twitter account and WSDOT regularly posts photos of construction.

A design concept of the State Route 99 tunnel that will replace the State Route 99 Alaskan Way Viaduct. (Credit: Washington State Department of Transportation)

A design concept of the State Route 99 tunnel that will replace the State Route 99 Alaskan Way Viaduct.
(Credit: Washington State Department of Transportation)

The project is currently halfway complete with the viaduct’s southern mile having been replaced with a more earthquake resistant and wider side-by-side roadway in 2011. This portion of the program was completed one year ahead of schedule and within budget, a Bertha-sized feat when it comes to large-scale infrastructure projects. The two sections will eventually connect in late 2015, when the new State Route 99 tunnel is anticipated to open to traffic.

This month, as we explore some of the world’s largest projects, the Collaborative Services blog spoke with KaDeena Yerkan, the Manager of Communications and Public Involvement for WSDOT’s  Alaskan Way Viaduct Replacement Program to learn more about the project’s history, the challenges it has faced along the way, and how the Department is continuing to use new and traditional methods for keeping the community informed of the program’s progress. Can you dig it?

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Reaching a consensus on the best way to replace the viaduct after the devastating earthquake in 2001 was not easy. How did the public come to support the version of the project now under construction?
The public was integral in shaping our plans for replacing the viaduct. The recommendation to replace the viaduct with a bored tunnel and other improvements came after a stakeholder group spent most of 2008 studying potential replacement alternatives. Options included elevated, tunnel and surface replacements. The tunnel was ultimately chosen because it was the only alternative that would allow us to maintain traffic on State Route 99 – one of two main north-south routes through downtown Seattle – during construction.

The groundbreaking ceremony at the State Route 99 South Holgate Street to South King Street Project in  June 2010. This project replaced the south end of State Route 99. (Credit: Washington State Department of Transportation)

The groundbreaking ceremony at the State Route 99 South Holgate Street to South King Street Project in June 2010. This project replaced the south end of State Route 99.
(Credit: Washington State Department of Transportation)

What are some lessons learned from the project’s contentious history?
Large projects demand thoughtful and inclusive planning, particularly when so many different stakeholders are involved. In addition to serving more than 100,000 vehicles per day, the viaduct is located in a dense urban area near two sports stadiums and the Port of Seattle’s busiest freight terminal. Gathering extensive input from all corners of the community was essential to selecting the best replacement alternative. There is no one solution that will make everyone happy, but by holding a thorough, transparent process we were able to gain public acceptance.

How do you keep the public informed about the status of the project and any construction-related impacts? What public outreach tools do you find most effective?
Communicating information about the project is an important priority. We use a variety of tools to inform and engage the public, including our website, social media, and presentations to community groups and professional organizations. We also staff information booths at community events and have a public information center near the work zone that has seen more than 18,000 visitors since it opened its doors in December 2011.

Crews ease the State Route 99 tunnel boring machine’s segment erector into place. (Credit: The Washington State Department of Transportation)

Crews ease the State Route 99 tunnel boring machine’s segment erector into place.
(Credit: The Washington State Department of Transportation)

The project is using the world’s largest-diameter tunneling machine, lovingly named Bertha. What can you tell us about Bertha and what can she accomplish in one day’s work?
At 57.5 feet in diameter – roughly as tall as a five-story building – our tunneling machine is the world’s largest. The machine was shipped to Seattle on the Jumbo Fairpartner, after successfully undergoing testing in Osaka, Japan, where it was built. It arrived in Elliott Bay on April 2, 2013, and was reassembled in an 80-foot-deep pit to the west of Seattle’s stadiums. Tunneling began on July 30, 2013 and is expected to take approximately 14 months.

Bertha weighs about 7,000 tons and is about the same size as some of the largest state ferries that ply the waters of Puget Sound. The Japanese firm Hitachi Zosen Corporation manufactured the machine for Seattle Tunnel Partners (STP), the contracting team that’s building the tunnel. Hitachi has successfully built more than 1,300 tunneling machines, a number of them for large-diameter tunnel projects. The machine will not officially become the property of STP until it has tunneled approximately 1,000 feet without any issues. As owner of the machine, STP is responsible for ensuring it functions properly.

Check out this short video to see the inner workings of a tunneling machine. Our Flickr site has photos of the machine’s journey from the manufacturing plant to its July 2013 launch beneath downtown.

To make Bertha's journey easier to follow the Washington State Department of Transportation has divided her route into 10 unique zones. (Credit: Washington State Department of Transportation)

To make Bertha’s journey easier to follow the Washington State Department of Transportation has divided her route into 10 unique zones.
(Credit: Washington State Department of Transportation)

The Washington State Department of Transportation has used social media to help the public track Bertha’s progress and to stay up to date on the project. How has the use of social media led to more effective communication efforts?
Social media is a valuable part of our communications efforts. It allows us to interact with the public in ways that weren’t previously possible, helping us reach new audiences and provide them with photos, videos and links to other information about the project. As important as social media has become, it is only one part of our broader communications strategy. Because many people don’t use social media, we still rely heavily on more traditional tools. Our project hotline, for example, allows people to speak with a staff member about their questions or concerns. We also make it a point to visit fairs and festivals in the area, in addition to presenting to local community groups, so that people can connect with our team in person. Our team has embraced social media, but face-to-face communication remains one of our strongest tools.

Credit: Washington  State Department of Transportation

Credit: Washington State Department of Transportation

Half of the viaduct has already been replaced, and the project is within budget and ahead of schedule. What have been some of the biggest challenges to accomplishing this?
Our job is to replace this vital stretch of highway while minimizing disruptions to traffic and the surrounding area. Balancing those two responsibilities isn’t easy, particularly with a project that is located near so many busy facilities that depend on their access to and from State Route 99. We also faced a very tight schedule and political challenges due to controversy about which alternative should replace the waterfront section of the viaduct. Finally, there are numerous technical challenges associated with a project of this magnitude, including designing and building the tunneling machine and launch pit, building the roadway within the tunnel and implementing a comprehensive program to protect structures above and near the tunnel route.

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We wish Bertha the best of luck as she continues building the State Route 99 tunnel. Follow Bertha’s progress on Twitter at @BerthaDigsSR99.

Liz Faris, Account Manager
Collaborative Services, Inc.

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Celebrating Labor Day all month long with BIG Projects

Credit: U.S. Department of Labor

Credit: U.S. Department of Labor

Here at  Collaborative Services, so much of what we do involves creating meaningful connections between big public infrastructure projects and the communities in which they’re being built.

So when Labor Day comes around, it lends us the opportunity to honor workers and recognize some of the awe-inspiring projects happening around the world. We did this last year and we return again this month for what we see as a worthwhile annual tradition.

The East Span of the San Francisco - Oakland Bay Bridge Credit: Bay Area Toll Authority

The East Span of the San Francisco – Oakland Bay Bridge
Credit: Bay Area Toll Authority

All of the projects we will profile in the coming weeks have one thing in common: They depend on healthy civic dialogue to be successful. Our blog will explore how these projects are being delivered to the public and how they are allowing people to get involved. These projects are big efforts with big price tags, and they include a big responsibility to inform and engage the public. This is not an easy task, but thanks to innovations in technology and the advent of social media, the public has more options then ever before to learn about projects in their communities and provide input.

The Colosseum, Rome, Italy Credit: Destination 360

The Colosseum, Rome, Italy
Credit: Destination 360

Some of the projects we will feature this month help improve infrastructure. While these projects often get a bad rap for being among the most costly, they make getting from one point to another safer and more efficient. They help advance water and energy supplies and their delivery methods. Improving infrastructure connects our communities and allows them to become better places to live, work and play.

It has always been a part of human nature to think big. From the Taj Majal to the Roman Colosseum to the Great Wall of China. Where there is the will, the need, and the funding, there is a way. We have only continued to think big with the advancement of technology and in the process created some of the most iconic projects in history, think of the Golden Gate Bridge, the Hoover Dam,  and the New York City subway system. It’s a big effort to take a project from inception to completion. This process can span years and in some cases generations, but these big projects have big benefits and manage to touch our lives in one way or another.

We hope you will join us this month on our journey to think BIG and will continue to share your thoughts and BIG ideas with us.

Liz Faris, Account Manager
Collaborative Services, Inc.

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