Crown jewel of Boston’s multi-billion-dollar Central Artery/Tunnel project, and the world’s widest cable-stayed bridge, the Leonard P. Zakim Bunker Hill Bridge was named the 2004 Outstanding Civil Engineering Achievement (OCEA) by the American Society of Civil Engineers (ASCE).
The OCEA winner was announced May 12, at ASCE’s fifth annual Outstanding Projects and Leaders (OPAL) awards gala at the Sheraton Premier in Tysons Corner, VA.
Selected from a group of 24 nominations, the finalists are magnificent examples of how civil engineering can improve the quality of life for local residents, contribute to a community’s economic success and inspire a nation.
• Leonard P. Zakim Bunker Hill Bridge, Boston — HTNB Corporation;
• Repavement of Kabul-Kandahar Road, Afghanistan — Louis Berger Group Inc.;
• Restoration of the World Trade Center PATH Station — Port Authority of New York and New Jersey;
• The New Braddock Dam, Braddock, PA — Pittsburgh District U.S. Army Corps of Engineers;
• William H. Natcher Bridge, Owensboro, KY — Parsons Brinckerhoff Quade & Douglas;
• Emergency Bypass Water Tunnel, Waipio Valley Hilo, HI — URS Corporation; and
• Integrated Water Transmission and Treatment Project, Clark County, NV — MWH, Las Vegas.
Leonard P. Zakim Bunker Hill Bridge
The Leonard P. Zakim Bunker Hill Bridge is the heart of Boston’s multi-billion-dollar Central Artery/Tunnel project and is the world’s widest cable-stayed bridge.
Crossing the Boston’s Charles River, the 10-lane bridge and its four-lane sister, the Storrow Drive Connector, will more than double traffic capacity in the city’s northern gateway.
The first four lanes opened to northbound traffic in March 2003, and when the bridge is fully operational in 2005, more than 110,000 motorists will travel the route daily to join with I-93 and Route 1. The $100-million bridge, praised by community leaders and residents, has become a city landmark.
“Not only was the city’s need for increased capacity met, but the local community has been given a new symbol of civic pride,” said Galloway. “The Zakim Bridge epitomizes the philosophy of form following function, which makes it a civil engineering marvel.”
Unique in several respects, the 183-ft. wide Zakim Bridge is the first asymmetrical cable-stayed bridge in North America. Its use of an ungrouted stay cable system is a first in the United States, as is its combined use of steel in the main span and concrete in the back spans.
Also on the bridge’s list of engineering firsts is a composite concrete tower with a high-performance steel inner core, and the use of internal viscous dampers and external helical beads on the stay cable to mitigate rain and wind oscillation.
All of these achievements were reached while working around several major site constraints.
The layout of the back span was dictated by the need to avoid an existing six-lane bridge, including the addition of temporary openings in the south back span for the existing bridge columns. The Massachusetts Bay Transportation Authority’s Orange Line subway and a critical 36-in. water main had to be isolated from construction impacts and the transfer of bridge loads through soil-structure interaction.
Despite these constraints, the designs and details were developed to maximize constructability, providing the contractor for the north back span with an option for incremental launching, and avoiding conflict with numerous other reconstruction activities in the area.
Repavement of Kabul-Kandahar Road
The repaving of 389 kilometers of the war-torn Kabul-Kandahar Road in only 230 days served as Afghanistan’s first step toward becoming a modern, stable nation.
In September 2002, the journey from Kabul to Kandahar took approximately 18 to 19 hours and for security reasons required an overnight stop along the road. The U.S. Agency for International Development (USAID) tasked Louis Berger Group Inc. with cutting down travel time and increasing safety as a part of the overall rebuilding of Afghanistan’s infrastructure.
Originally, the assignment called for repaving only 49 kilometers by December 2003, but in April 2003, President Bush promised Afghan President Karzai that the entire Kabul-Kandahar Road would be repaved by December 2003. Recognizing the technical, financial and security constraints, Louis Berger committed to developing a rehabilitation and reconstruction plan. By July 2003 travel time has been cut in half.
“The road repaving project is a civil engineering marvel not only for its resourcefulness and pioneering techniques, but also for its contribution to the security and well-being of the Afghan people,” said ASCE President Patricia Galloway. “Ultimately, it will assist in unification and strengthening national and regional governance.”
Improving traveling conditions for the public has not only decreased travel time and vehicle operating costs, but it also has increased safety by allowing the trip to be made entirely during daylight when the opportunity for banditry is reduced.
Lane striping has increased traffic safety by designating lanes for each direction, and widened, paved shoulders allow broken-down vehicles to pull off rather than blocking the road and creating a potential hazard. Dust reduction provided by the new paved road has diminished air pollution and its resulting potential health problems.
In addition, local farmers and tradesmen have been given greater access to commercial centers, which will bring new opportunities for economic growth.
In order to meet the deadline it was given, Louis Berger employed several innovative techniques, including an asphalt base that utilized locally available river-run and quarry gravel, that could be laid down in two or three layers. This allowed the road to be paved and dust-free, with an average speed of approximately 100 kmh as soon as the first layer was complete.
It also proposed a unit rate contract that would allow contractors to begin work in advance of design, and that included provisions for materials, security-related stoppages and scope adjustments based on performance.
Given that Afghanistan has the highest density of landmines in the world, the most important innovation used was the landmine detection method. Traditional methods were notoriously slow, so Louis Berger brought in armored, mechanized, GPS-controlled vehicles to collect air samples from alongside the highway. The samples were then sent to a lab where mine-detecting dogs were allowed to sniff the samples.
If the dogs detected the presence of a mine, teams were sent to the site to remove it using the traditional method. This process resulted in a 400-percent increase in the de-mining rate, which increased safety not only for the construction teams, but for the residents as well.
The Downtown Restoration Program’s Temporary World Trade Center (WTC) PATH Station serves as a portion of the Sept. 11 rebuilding process.
When the WTC towers collapsed on Sept. 11, 2001, the PATH station that occupied the lowest level of the site also was destroyed. Along with the station, the two tunnels that connected it to the New Jersey Exchange Place station also were heavily damaged. PATH users, who at its peak operating capacity numbered 241,000 daily, were forced to turn to less convenient means of travel between Manhattan and the neighboring New Jersey communities and suburban commuter railroads.
On Dec. 13, 2001, the Board of Commissioners and the Port Authority of New York and New Jersey gave the Downtown Restoration Program authorization to re-establish PATH service to lower Manhattan. The WTC station opened to the public one month ahead of schedule on Nov. 23, 2003.
“The temporary WTC PATH Station not only restored service to commuters, but it also helped the local communities in their continuing struggle to recover from the devastating effects of the Sept. 11 tragedy,” said ASCE President Patricia Galloway. “Those things combined are what make it a civil engineering marvel and a symbol of inspiration for the country.”
The project’s primary phase included rehabilitating the 1-mi. long “E” and “F” tunnels, expanding the Exchange Place station, and designing and constructing the temporary WTC station. The tunnels, which required the removal of floodwater and contaminated mud-damaged infrastructure, were gutted and a state-of-the-art track system was installed, all in less than a year.
Attention was then turned to the Exchange Place station, which was slated for a summer of 2003 opening. To reduce noise and vibration disruption to the neighboring community, the project team elected to use a roadheader instead of the traditional drill and blast methods for excavation. This not only helped to avoid damage and liabilities, but it also allowed the team to expand the excavation project to a 24-hour schedule. This in turn allowed crews to complete the restoration and expansion of the station in only 18 months.
Finally, the team decided that the fastest and most logical solution for the WTC station was to restore it to the pre-Sept. 11 configuration of three platforms and five tracks.
The station features a mezzanine level above the platforms that provides access to the street under a new canopied plaza. The two levels are connected with stairs and elevators, and are located within the existing “bathtub” area. The station also features an open-air design, which employs a portion of the original concourse to reach the new Church Street entrance.
Keeping in mind that the station is located on an active construction site, precautions such as filtered air ventilation in the terminal as opposed to traditional exhaust fans, were taken to ensure the commuters’ safety.
The team also took the opportunity to make some improvements to the transportation hub, including new turnstiles that accept both PATH and MTA fare cards, allowing customers to transfer systems with greater speed and ease. Completing restoration and improvement construction simultaneously reduced costs and operational impact.
New Braddock Dam
The New Braddock Dam, an important component of the nation’s Inland Waterway System, was constructed with an innovative in-the-wet technique, used for the first time by the Army Corps of Engineers.
Its signature feature, the fabrication, assembly and delivery of two football field-sized concrete segments, required floating the 11,000- and 9,500-ton pieces 27 mi. upstream on the Ohio and Monongahela rivers. These two pieces combined to form the New Braddock Dam, which replaced the approximately 100-year-old fixed crest dam, allowing the Corps to replace the inefficient older locks upstream and completely eliminate the severely deteriorating dam 3 and the locks.
“As a result of the constraints in the federal budget for infrastructure improvements the Corps took initiative and adopted a pioneering cost-saving technique to sustain the nation’s navigation system,” said Galloway. “The innovation, perseverance and dedication that went into making the New Braddock Dam possible are what make it a civil engineering marvel.”
In only 10 months, more than 700 drawings and 3,000 contract pages were prepared, including unique design criteria for floating the dam structures, which, given that the Corps had no existing guidelines for such technology, had to be developed from scratch.
The designs eliminated the need for conventional cofferdams to dewater the construction site, which reduced cost, allowed for concurrent construction of the foundation and dam structure, which reduced time, and called for pre-casting in a controlled environment, which increased quality.
After a best value-trade off negotiated procurement was conducted by the Pittsburgh District, the $107.4-million contract, was awarded to the joint venture of J. A. Jones Construction Company and Traylor Bros. Inc.
The dam, which helps sustain the $8 billion in annual commerce that travels through the Port of Pittsburgh and the 34,000 jobs directly linked to the local waterways, had an impact on the physical environment.
More than 400,000 cu. yds. of dredged and excavated foundation materials were reused as cap matter on the former U.S. Steel Duquesne Works Brownfield, saving millions of dollars and restoring an economic generator in the economically-depressed Monongahela River steel valley.
The construction methods also eliminated the need for cellular cofferdams, and the associated risk of increased flood levels during construction. The dam contains a water quality gate, which sustains improved dissolved oxygen levels in the Monongahela River.
William H. Natcher Bridge
The William H. Natcher Bridge set a new standard for landmark bridge design.
Carrying Route 231 across the Ohio River from Owensboro, KY, to Rockport, IN, the four-lane, 4,505-ft. bridge opened to traffic on Oct. 21, 2002. Parsons Brinckerhoff Quade and Douglas Inc., principal designers, and Traylor Bros. Inc., were challenged by the Kentucky Transportation Cabinet to combine technical innovations with beauty, simplicity and economy in the bridge named for the late U.S. Congressman.
Their solution, which was completed on time, within budget and with no claims, features one of the longest main spans over the inland waterway system. The bridge had become a regional landmark, and is embraced by the local communities as a symbol of friendship and common economic aspirations.
“While the bridge is prized for its size and beauty, the range of innovations used to ensure its integrity makes the William H. Natcher Bridge a civil engineering marvel,” said Galloway. “Not only was the need for mobility met, but a whole new area has been opened to economic growth.”
Designed to aid in future upkeep, the bridge’s tower tops, which measure 260 ft. above roadway level, also include a 103-ft. tall chamber where the cable stays are anchored. These chambers are fitted with ladders and platforms that simplify access to the anchorages, warning lights, air circulation vents and lightning rods, allowing proper and frequent inspections, ensuring safety and cutting costs.
The deck’s cable-to-girder design also provides easy access for inspection and maintenance without requiring special equipment.
In addition to its technological advance, the bridge was designed to have a minimal impact on the physical environment. In order to protect the farming community on the Kentucky side, a hydraulic modeling analysis was done for the flood plain, with and without the bridge, for flood cycles of both 100 and 500 years. This marked the first time such an analysis was done for a bridge project in the United States. On the Indiana side, construction time was limited to October through March for the river pier foundations, to diminish impact on the mussel beds.
Hakalaoa Falls Emergency Bypass Tunnel
The Hakalaoa Falls Emergency Bypass Tunnel on the island of Hamakua, HI, repaired a 15-year-old tunnel collapse, returning a steady water supply to local farmers.
In 1989, a catastrophic landslide collapsed a 30-ft. section of the 90-year-old Lower Hamakua Ditch water system, first constructed to supply water to the local sugar cane farmers. A temporary 25-ft. wooden flume was built across the collapsed tunnel to restore flow to the 24-mi. long water system, but rocks loosened by the landslide continued to plague the emergency flume.
Ultimately, the water was diverted above the Hakalaoa Falls, costing local farmers $11 million and doing significant damage to the Waipio Valley ecosystem.
In 2001, the state of Hawaii decided to restore water to both the farmers and the ecosystem, selecting the design/build team Jas. W. Glover Ltd./URS Corporation to construct an emergency bypass tunnel. The tunnel was completed April 2002, and is hailed as only the second stream restoration in the state’s history.
“This project is an incredible example of how unique challenges can be overcome by civil engineering,” said Galloway. “Not only is the agricultural community’s need for an irrigation system restored, but the ecosystem and treasured twin falls were not compromised, which is what makes the project an engineering marvel.”
The project’s location at mid height on the 2,000-ft. Hakalaoa Falls offered the team multiple challenges, including the on-going danger of the further cliff face collapse and highly restrictive access to the project site.
In addition, engineers were faced with a limited budget, shortened time frame and public outcry for immediate restoration of the water supply. The team’s solution, a 300-ft. long, 7-ft. in diameter, hand-mined, liner plate supported bypass tunnel, was built without the use of tunneling machines and drilling robots. The team was allowed to shut down the system for only one day to perform a site investigation, and the geologic deductions were done by extrapolating conditions observed on the face of the cliff by helicopter and geological mapping inside the tunnel.
Due to restrictions on disposal of excess materials into the sacred Waipio Valley, 1,000 tons of excavated rock had to be hauled out from the site through an existing 2-mi. long tunnel, in addition to the 300 tons of new construction materials that had to be brought in.
For safety reasons, speed in the tunnel was limited to 5 mi. per hour, thus requiring an hour-long round trip. With more than 1,300 tons of materials to haul at one-half ton per load, and a distance of 2 mi. one way, cumulative distance for all materials amounted to more than 5,200 mi., farther than a round trip from San Francisco to Washington, D.C.
Despite the emergency tunneling project’s many challenges, it was completed on schedule, within its $2.7-million budget, without claims and with no discernable impact on the environment, costing $17 million less than building a new tunnel.
Integrated Water Transmission and Treatment Project
The Integrated Water Transmission and Treatment Project enhanced and expanded Southern Nevada’s drinking water supply system.
Noting the population explosion in the Las Vegas Valley, the Nevada Water Authority embarked on an extensive development project for its existing drinking water supply system.
The ensuing design, a joint venture between MWH and CH2M Hill, incorporated features that addressed aesthetic, safety and environmental concerns, as well as providing educational opportunities to the local communities.
To ensure compliance with future regulations and treatment standards, the design included a high-level of flexibility and additional physical space to accommodate growth. The water supply capability had increased 25 percent by 2002, and it’s expected to increase an additional 25 percent by 2005. Southern Nevada residents began receiving high-quality water from the $2-billion system in 2002.
“Not only does this system meet the needs of the surrounding communities, but it does so while maintaining a minimal impact on the environment,” said Galloway. “Those things combined are what make this water system a civil engineering marvel.”
The system’s architectural elements were designed to minimize visual impact, to preserve the natural beauty of the desert and mountain region. Unique masonry and concrete were utilized to mimic the desert’s natural colors.
In addition, approximately 50 percent of the 415-acre site was left in its natural desert condition. A special fencing system was designed to protect the endangered desert tortoises, which make their way home within the acreage. All personnel received thorough training to aid in their preservation.
In addition to the project’s environmental innovations, several large scale advanced technologies were used. The treatment facility was planned using integrated three-dimensional design technology, making it one of the first and largest to do so. The system’s hydraulics were created with laboratory scale and computerized models.
One of the world’s largest sodium hypochlorite generation facilities was implemented to alleviate concerns over the safety of transporting liquid chlorine, and the 3,000-ft. raw water aqueduct is one of the world’s largest underwater pressure pipes
For more information, visit www.asce.org/opal.
Photo: Crown jewel of Boston’s multi-billion-dollar Central Artery/Tunnel project, and the world’s widest cable-stayed bridge, the Leonard P. Zakim Bunker Hill Bridge was named the 2004 Outstanding Civil Engineering Achievement (OCEA) by the American Society of Civil Engineers (ASCE).