New York City Transit (NYCT) needed noise and vibration services related to the design of the first new subway line in New York City in over 50 years. The 2nd Avenue Subway will run between 125th Street and Battery Park in Manhattan, adjacent to a variety of noise- and vibration-sensitive land uses such as residences, hospitals, and television studios.
Under sub-contract to the joint venture of DMJM-Harris/Arup, HMMH performed detailed vibration measurements along the subway route to determine the vibration characteristics of the ground along the line, and to obtain source vibration levels for NYCT rapid transit vehicles. The vibration measurement program involved six weeks of testing and included vibration measurements in two of the existing tunnel segments that were built in 1972 under 2nd Avenue. It also included measurements in live subway tunnels and in boreholes drilled by geotechnical engineers.
In addition, HMMH performed vibration measurements at existing NYCT subway tunnel locations to evaluate the vibrations generated by trains passing over rail gaps at track crossover locations.
The information obtained from these measurements will be utilized for noise and vibration impact analysis during final design.