The last Rapid Excavation and Tunnelling Conference (RETC) was held in San Diego in June and attendees agreed it was one of the best attended and most upbeat in memory. The US tunnelling and underground construction industry is doing well, with a good amount of work on the horizon and an adequate number of designers and contractors vying for that work.
American Underground-Construction Association (AUA) surveys of active projects reveal that major transportation projects are either under way or planned in New York City, Boston, Washington DC, San Francisco, Minneapolis, Seattle, and San Diego and that the number of water/wastewater projects, large and small diameter, are too long to list. The following is a synopsis of some of the more significant tunnelling undertakings.
California is involved in the planning, design and construction of a number of major transportation tunnelling projects. In the San Francisco area alone, projects include the Devil’s Slide Tunnel, the fourth bore for the Caldecott Tunnel, a new transportation link in downtown San Francisco, and a transit extension of the regional BART system down to San Jose. In southern California, tunnelling projects include the Riverside Badlands and Arrowhead water tunnels, the NOS East Central Interceptor Sewer tunnels, the Mission Valley East Light Rail Project, and the San Vicente Pipeline.
In Seattle, though, the Sound Transit Project was dealt a setback; final design is proceeding with the Beacon Hill project south of Seattle.
In Portland, where the Willamette River flows through town, the City is continuing its Clean Rivers programme with major combined sewer overflow (CSO) tunnels along the west and east sides of the river.
Tunnelling activities are bustling in the mid west. Major sewer and CSO tunnelling contracts are under construction in Cleveland OH, with two large diameter storage and conveyance tunnel systems in the planning stages. The Detroit River Outfall Tunnel is under construction, and the Upper Rouge River CSO Tunnel is currently being planned. Major sewer and CSO tunnelling projects are also under construction or in the planning stages in Cincinnati, Columbus, St Louis, Toledo, and Indianapolis.
In the south east, wastewater tunnels include the Chattahoochee and Nancy Creek tunnels in Atlanta, and new CSO tunnels in Charleston SC, and two new immersed tube tunnels are planned as a part of the Hampton Roads Third Crossing in Virginia Beach, VA.
Although New York City has been referred to lately as “Ground Zero” for all of the wrong reasons, it is also ground zero for some of the most exciting tunnelling projects in the world. Among specific opportunities are:
The city of Boston is still heavily involved ith underground projects although many are now either complete, such as the Boston Outfall and the InterIsland tunnel, or in the later stages of construction. The MetroWest tunnel has holed through and the Braintree-Weymouth Tunnel is well under way. Planning is continuing for the South Dorchester CSO tunnel and other major CSO projects are under way for Fall River and New Bedford, MA and Providence RI. Construction of the Big Dig continues with completion in 2005.
As the US infrastructure grows, airport improvements are ongoing at virtually every major airport facility in the country. To facilitate these expansion projects with minimal surface impacts, many airports are looking toward tunnelled landside and airside transport systems. At Minneapolis-St Paul International Airport, a transit crossing of the airport with a subway station beneath the terminal is being constructed. Denver is looking at expanding its extensive network of tunnels, and a major expansion is being planned in Los Angeles. There is little doubt that security concerns in airports will accelerate this trend toward underground transport networks.
Despite the rosy outlook, the US tunnelling industry continues to struggle with various contracting issues that result in a great deal of positioning among stakeholders for many tunnelling projects. The country has one of the most competitive construction environments in the world, with owners trying to squeeze every last dollar out of each project and contractors required to aggressively bid almost every under-ground project on the market.
Many experiments to improve this situation have been attempted in the United States including geotechnical baseline reports, escrow bid documents, and dispute review boards. Although the use of these practices has generally improved the contracting environment, they are not the ultimate solution. Most foreign contractors that have tried to do business on US projects have had major problems and the number of national tunnelling contractors still operating in the US has dwindled, while other tunnelling contractors have maintained successful practices in more regional areas, the effects of bitter competition in the tunnelling industry are apparent.
Foremost among the problems faced by these contractors are ever increasing requirements to assume additional risk, and having to withstand both large negative cash flows and low profit margins.
It is interesting to note that the latest domestic “experiment” is the use of the design/build approach to contracting for tunnelling projects as compared with design/bid/build. Although design/build has many advantages for certain types of projects, the jury is still out on whether this will work for underground projects, especially in urban areas.
Owners are beginning to see the downside effects of the low bid process as well. On more difficult projects, they are unwilling to simply accept the lowest bid award method, and are exploring improved means of advanced partnering. The City of Portland, Oregon is pursuing an approach that involves the evaluation of pre-qualified teams on the basis of proposals and interviews, where cost is only one consideration in the evaluation and selection process. The successful contractor team will be retained to provide input during a “Pre-Construction” period coincident with the project’s final design, and if judged suitable, will carry out the construction under a separately negotiated contract.
No one can think of the United States right now without wondering about the impact of the tragic events of 11 September. Although the initial shock and ramifications were very bad, the US is a strong and resilient country. The federal government is planning for increased spending for infrastructure to stimulate the economy, with an increased emphasis on security, and no type of project has better security characteristics than underground construction.
In New York, it is difficult to determine the full impact of World Trade Center events on the degree to which resources from planning assignments will be diverted to more pressing needs. Clearly, the devastation at the World Trade Centre has severely affected underground transit facilities, including the Port Authority of New York and New Jersey’s Trans-Hudson PATH transit tunnel system which terminated at the complex, and two subway lines operated by the New York City Transit Authority’s tunnels which are also located directly beneath the destroyed buildings.
All in all, the US underground construction industry is doing fine. All indications are that demand for improved transportation systems, water distribution networks and the restoration of rivers, creeks and harbours in our urban areas, will remain strong for the foreseeable future.
