One hundred fifty feet below the streets of Midtown Manhattan, the largest and most expensive transportation infrastructure projects in the United States is underway. East Side Access will connect Grand Central Station to the Long Island Rail Road via a six-mile-long tunnel that when completed, is expected to serve 162,000 commuters every day.
“In order for a project of this scale to move forward, a variety of infrastructure improvements must be constructed,” explained Lynn Stocker, marketing manager for Strata Systems. “StrataGrid® was used to construct a 63-foot mechanically stabilized earth (MSE) temporary retaining wall that not only met the project’s unique space constraints and 10-year design life requirements, but helped this phase of the project stay on time and on budget.”
The East Side Access project includes miles of tunneling that encompasses work in multiple locations across Manhattan, Queens and the Bronx. Because the vast majority of the project is taking place underneath a heavily populated urban environment, material delivery is especially difficult. “A large crane had to be used to deliver the StrataGrid material into the 70-foot hole that abutted vertical walls on either side where the MSE wall was being constructed,” Stocker said. “Since StrataGrid is rolled and easy to handle, it made material transport and delivery much more efficient.”
Contractor Tutor Perini Building Corporation installed approximately 30,000 square yards of StrataGrid to build the reinforced MSE temporary wall. The wall solves the grade separation issues while offering major cost savings versus conventional technologies.
“The quality of Strata’s products and services allowed our firm to design the temporary retaining wall with confidence. This was important to us given the significance of the overall project and the critical nature of the temporary wall,” said Chad Clark, professional engineer and principal at Clark Geotechnical LLC. “Plus, the structure is likely one of the tallest single-height MSE temporary walls constructed in the United States using welded wire form facing and georgic reinforcement.”
With the construction of the MSE wall, the East Side Access tunnel project continues to progress, and will eventually provide faster and safer travel to thousands of passengers every day.