Attenuation of Pipe Ramming-Induced Ground Vibrations

Pipe ramming installations generally induce high levels of ground vibrations that may affect the structural integrity of nearby buildings and utilities. This paper investigates the ground vibrations associated with pipe ramming installations and develops reliable models for estimating the ground vibration levels in an effort to avoid the undesirable effects of the vibrations. The study presents field observations of ground vibrations in which an open-ended steel casing 1,070 mm in diameter and 37 m long was driven into granular soils using two pneumatic hammers of varying energy. The ground vibrations observed during the installation are presented as a function of magnitude of peak particle velocity, frequency content, and direction of propagation. Observations indicate that a wide range of amplitudes and frequencies is possible, ranging from 1 to 100 mm/s and 20 to 100 Hz, respectively, for the case of forward and laterally propagating vibrations. The forward-propagating vibrations were observed to exceed the safe limit vibration criteria for a proposed pipe alignment for close source-to-sensor distances, indicating a potential for damage caused by pipe ramming-induced vibrations. The attenuation characteristics of the pipe ramming-induced vibrations were assessed by adopting and calibrating the existing scaled-distance empirical model and compared to those for a number of common construction operations.