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Project Design Team and Preliminary Design Process
Reflecting the Bay Area's Vision
The California Department of Transportation (Caltrans) is on a fast track to complete the seismic upgrade for the east span of the Bay Bridge. The East Span Project covers the portion of the bridge between Yerba Buena Island and the Oakland shore. Denis Mulligan, Caltrans Toll Bridge Program Manager, is part of the project team. Mulligan explains that this is a very exciting project-and an immense undertaking. The process requires balancing complex issues, the concerns of many stakeholders and an aggressive schedule. He says a key focus of the project team is to reflect the Bay Area's vision for the bridge. "It's our job as technical experts to provide information," he explains. "But we also need to work with the Bay Area to understand their views in order to deliver the best possible project."
This complex project involves extensive coordination among various agencies, interest groups and stakeholders. At the forefront of this effort is a unique, cooperative relationship between Caltrans and the Metropolitan Transportation Commission (MTC). Caltrans owns and operates the bridge, consequently they make decisions regarding seismic safety, operations and maintenance. MTC provides regional transportation planning and oversees decisions on funding for Bay Area transportation projects. MTC's primary role for the project involves reviewing and recommending bridge designs and possible amenities, with a particular focus on funding issues. MTC is composed of representatives from the nine Bay Area counties, allowing a cross section of different viewpoints from throughout the region. Mulligan is pleased with the partnership between Caltrans and MTC. "This is a solid, productive working relationship," says Mulligan. "Together we bring a breadth of resources and knowledge to the project."
In August 1997 Governor Wilson signed a law establishing a $1 surcharge on state-owned toll bridges for eight years to help pay for the cost of retrofitting them. The law also authorized MTC to extend the surcharge for up to two additional years to fund up to three amenities on the East Span Project. These include a cable-supported bridge, relocation or replacement of the Transbay Transit Terminal in San Francisco, and the addition of pedestrian/bicycle access on the new span.
There are cost considerations associated with the project amenities. Mulligan explains that MTC will be working with the public to make recommendations on bridge design and amenities. "The recommended design must be acceptable to Caltrans in terms of seismic safety and maintenance," he says. "But ultimately it's the Bay Area's decision. Caltrans will build as much bridge as the Bay Area wishes to fund."
Over the next few months, MTC will hold meetings to review the bridge designs and amenities. These meetings are an opportunity for the public to provide input before major decisions are made. "It's key that people get involved now," Mulligan says. "Early public input is critical to ensure that the Bay Area's interests are represented." Caltrans is conducting an aggressive public outreach program for the project. As part of the program, Caltrans has met with environmental, community, business and other interest groups and has formed an advisory committee, which includes bicyclists and members of the disabled community, to provide input on the design of a possible pathway. Caltrans has held and will continue to hold public meetings throughout the region. "It's important for us to provide as much information as we can and to hear from the public so that together we can make informed decisions," Mulligan explains.
Mulligan points out that the project has a very challenging schedule. In response, Caltrans has assigned an unprecedented level of resources to the project. "This is a public safety project first and foremost," he explains, "so there's high motivation on the part of Caltrans and the entire team to implement the project as soon as possible."
Even with all the challenges, Mulligan sees tremendous opportunities in the East Span Project. "This project will change the look of the Bay for the next 100 years," he says, "and it's important that people share their vision for it."
Two cable-supported bridge design are being reviewed byCaltrans and the MetropolitanTransportation Commission (MTC): a cable-stayed alternative and a self-anchored suspension alternative. A full-skyway concept has already been developed by Caltrans. After a competitive process involving many firms, Caltrans selected three engineering consulting teams to provide technical expertise on the project. All three firms bring worldwide and local experience to the project. The joint venture team of TY Lin International/Moffatt & Nichol Engineers is developing the bridge concepts. Parsons Brinckerhoff Quade & Douglas, Inc. is working on highway design and environmental studies. Fugro West and Earth Mechanics are conducting geotechnical and seismic studies.
TY Lin International is a world-class firm recognized internationally for its work in designing technically innovative and aesthetically pleasing bridges. The San Francisco-based firm has been designing bridges and other structures for over 40 years. Among their projects are the Golden Gate Bridge seismic retrofit, the Glebe Island Bridge in Sydney, Australia, and the Talmadge Memorial Bridge in Savannah, Georgia. Moffatt & Nichol specializes in highway, bridge, rail and marine structure design. The firm's projects include the approach and causeway for the Ford Island Bridge in Pearl Harbor, Hawaii, the Willamette River Bridge in West Linn, Oregon, and the Vincent Thomas Bridge seismic retrofit in Los Angeles. Parsons Brinckerhoff has provided environmental and design services on many Bay Area projects including the Benicia-Martinez Bridge seismic retrofit and new ramps at San Francisco International Airport. Fugro West recently completed geotechnical studies for the other Bay Bridge retrofit projects.
Following the guidelines and recommendations set by MTC's Bay Bridge Design Task Force and Engineering and Design Advisory Panel, the teams are working on highway designs, planning studies and 30% design plans for both the cable-stayed and self-anchored suspension concepts. MTC and Caltrans will use this information to review the bridge concepts for seismic performance and reliability, operations, safety, environmental impacts, bridge aesthetics, construction schedule and costs. "This is a critical time in the project's development," explains Ken Jong, Civil/Environmental Consultant Team Manager. "The preliminary design engineering we're working on now will guide the final decision about what a new bridge will look like."
One element of this work that people find intriguing is the concept of "30% design." Rafael Manzanarez, Structures Design Manager, explains the process. "In any engineering project, there are basic factors that remain fairly constant, but which vary according to the design, such as materials, site preparation, etc. Once you develop these elements to a 30% level, you get a clear sense of how the entire project shapes up," says Manzanarez. "You can begin to accurately analyze and predict things such as seismic performance and cost, and you can make comparisons among the designs." Al Ely, Structures Consultant Team Manager, explains that this is a common-and smart-practice. "Doing 30% design is an efficient and cost-effective approach," he says. "It provides sufficient detail for many selection criteria, allowing MTC and Caltrans to judge each bridge concept and make an informed decision on the final design."
In addition to seismic safety and cost considerations, MTC will also judge each concept on visual characteristics. "We understand that people are very interested in the bridge's appearance and want it to reflect and complement the unique beauty of the Bay Area," says Manzanarez. Jong adds, "Views to and from the bridge are equally important. The proposed single deck structure will dramatically enhance the bridge user's experience with expansive views of the East Bay."
MTC will provide its recommendation to Caltrans on a bridge design in June. Several Bay Bridge Design Task Force meetings will be held to review the design work. The design team encourages the public to attend these meetings. "The teams are excited to be designing a bridge that will benefit the entire Bay Area," says Ely. "We're all very interested in hearing the public's ideas."
The Metropolitan Transportation Commission (MTC) is moving into a critical phase of its involvement in the East Span Project: the design review process. MTC's Bay Bridge Design Task Force and Engineering and Design Advisory Panel (EDAP) have begun reviewing preliminary design work on the two cable-supported concepts for a replacement bridge. Additionally, EDAP is refining its design guidelines to assist the design team in developing concepts that will meet the evaluation criteria.
In March, the design team presented its first concepts to the architects and engineers who make up EDAP. Variations of the cable-stayed and self-anchored suspension concepts were presented with single towers, double portal towers and triple towers. All concepts were designed with and without pedestrian/bicycle access. EDAP asked the design team to carry forward the single and double portal towers for both the suspension and cable-stayed concepts. The triple tower design did not meet the evaluation criteria and was eliminated from further consideration. The design team will continue to develop concepts based on EDAP's recommendations. At the April 15 EDAP meeting the panel reaffirmed the need to study two concepts for each cable-supported bridge type and made a formal motion for the design team to consider placement of pile caps above the water. Details on the bridge concepts are available on MTC's website at www.mtc.ca.gov. On the MTC website visitors can provide input on which bridge design they like best.
The 30% design process is expected to be complete in May. MTC will evaluate the designs for seismic performance, visual appearance and cost. MTC will make its final recommendation to Caltrans on a bridge design and other proposed amenities in June.
Environmental studies for the East Span Project's Draft Environmental Impact Statement (EIS) have been underway for several months, and the technical specialists are making significant progress. The studies will identify potential impacts of five project alternatives being considered. These include no-build, retrofitting the existing span, and three replacement alternatives-two alignments north of the bridge and one alignment south of the bridge. If a bridge replacement is selected, the design will follow one of the three alignment alternatives. Impacts to 16 issue areas ranging from air quality and traffic to endangered species and land use are being examined. Progress updates for some studies are outlined below.
This analysis covers plant and animal life in the project area that are considered "special status." This includes species that are listed as threatened or endangered by state or federal law, or those that warrant "special concern."
Biologists have analyzed the species and possible impacts, which have been detailed in a Biological Assessment that will be certified by the U.S. Fish and Wildlife Service. One special-status plant and nine special-status wildlife species have been identified. The marsh gumplant grows on the Yerba Buena Island and Oakland shores. The double-crested cormorant and American peregrine falcon nest and breed in the existing East Span structure. Special-status shorebirds include the common yellowthroat, Alameda song sparrow, California clapper rail and California least tern, which breed and forage on the Oakland shore. Steelhead trout, winter-run chinook salmon and Pacific herring are also being considered in the assessment. Mitigation measures will be developed to avoid or limit potential impacts to these species.
This issue area examines the geologic conditions of the site where a new bridge would be built. Geology investigations are critical in designing a structurally safe bridge. The Bay's geology poses challenges because bedrock is at the surface on Yerba Buena Island, but it slopes to the east and is deep beneath layers of sediment under most of the existing east span structure and at the Oakland touchdown. This means that the bridge piers on and near Yerba Buena Island would be anchored in bedrock, while all the other piers would be anchored in sediment above the bedrock.
Fugro West, Inc. is studying the characteristics of the bedrock and sediment in the project area. The team has performed geophysical seismic reflection studies by sending low-level seismic waves through the rock strata beneath the Bay. The return waves provide data on various geologic characteristics. Drill samples and cores have also been taken at locations on land and in the Bay. The bridge designers will use the data from these investigations to help them propose the best location for the bridge piers, and to begin working on pier design. Once pier locations are proposed, Fugro will perform more drilling at those sites to help fine-tune the designs. Results of the geologic investigations will be summarized in the EIS.
One of the issues being considered for the East Span Project is the possibility of creating a shoreline park and a "gateway" to Oakland and the East Bay where the bridge touches down on the Bay's eastern shore. This issue will be addressed in the land use and visual impact studies.
The East Bay Regional Park District, Oakland Army Base, Port of Oakland, City of Oakland and the project team have begun a cooperative planning process to explore options. They met recently to discuss opportunities, constraints and concerns regarding the park and gateway. Topics ranged from recreational access, long-term management and ownership, views and historical considerations to ideas for the gateway. Preliminary concepts of possible park and gateway ideas are being prepared and will be presented to the project team and the public for input. Although there is no funding for the park at this time, the planning and collaborative process is continuing.
Both Caltrans and MTC are committed to keeping people informed about the East Span Project and providing opportunities for public participation. Caltrans hosted open house meetings in Oakland, Walnut Creek, and San Francisco in December 1997 and in Solano County in March 1998. Over 300 people viewed project exhibits on design, alignments, funding and other project elements. They also asked many questions and provided valuable comments to the project team. People were most interested in bridge design issues, pedestrian/bicycle access, and the project review process.
Upcoming opportunities for public input include the MTC Bay Bridge Design Task Force and EDAP meetings this spring and public meetings later this year on the environmental document. Questions and comments are also welcome via phone, mail or e-mail.
MTC's Bay Bridge Design Task Force has been meeting for over a year and issued design guidelines for the East Span Project in July 1997. MTC's primary role at this time is recommending bridge design and amenities to Caltrans. The public, the Engineering and Design Advisory Panel (EDAP) and the Bay Bridge Design Task Force provide input to MTC on selection of the bridge design. Under state law, MTC's recommendation will guide the final decision on bridge design. The bridge design selected must comply with NEPA and be consistent with the Final EIS.
Throughout the process, Caltrans is conducting public outreach and coordinating reviews and permitting with other agencies. Following its design recommendation to Caltrans, MTC will continue to serve in a key capacity through release of the Final EIS. The chart below depicts the activities and coordination of Caltrans, MTC and the public.
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