As the Alameda Trench Corridor in California celebrates the opening of a three-year, $2 billion, 10-mile-long trench construction project, other projects of similar purpose are on the horizon in Reno, Nevada, and Placentia, California. These ventures signal a new era of trench construction and railroading.
The catalyst for these trench projects is the expansion of international trade and the capacity of American railroading to foster faster distribution of goods. New cargo ships deliver merchandise to our shores in huge quantities: 2,500 containers per ship. High-speed unloading cranes deliver these containers to port facilities at the rate of one every two minutes. Consequently, railroad traffic increases dramatically, since a large percentage of the container cargo is transshipped by rail to other destinations.
Along with significant increases in rail traffic, one other shared
trait of these projects was the location of the rail line-at street
level through growing urban areas. Increased rail activity snarls
auto, truck, and emergency vehicle traffic and creates severe congestion
where roads cross tracks. Relocation and grade separation are the
only feasible alternatives. The trench corridors solve these transportation
problems and are made possible by the use of trench technologies
developed in the past several years. Various wall systems for deep
trench excavation and retaining systems include diaphragm wall,
secant pile wall, tangent pile or contiguous bored pile wall, soil-mix
wall, and jet-grouted wall. Each system requires specific types
of equipment to attain the desired result, but all require cast-in-place
concrete, bentonite/cement mixtures, soil-cement, or cement grout
to provide the structural rigidity necessary to retain soils and
provide water tightness. Travel speeds in the new corridors are
significantly greater and many more trains are now able to safely
transport goods. The Alameda Project demonstrates financial and
contractual innovation as well as technical success. Most certainly,
it will serve as the model for others to follow.
Trench Technology