Field trial for the evaluation of ground-borne vibrations: East West Rail case study

Propagation of ground-borne vibrations involves a plethora of complex factors whose prediction is difficult due to limited current research. This is particularly so for buried structures, as most of the existing field research and equations are based on measurements at ground level. For sensitive construction sites, field trials are usually recommended. This paper presents results from a field trial for East West Rail Phase 2, where the new trackbed interacted with large-diameter, high-pressure gas pipes. In order to simulate the trackbed compaction, a vibratory roller was tracked over the ground surface, while a seismograph measured peak particle velocity (ppv) at 1.2 m depth. The attenuation data were analysed using equations that were derived from extensive field trials carried out by the UK Transport Research Laboratory (TRL) and are incorporated in UK codes and standards. Comparisons are made from which it is shown that the TRL equations overpredicted the ppv, and the authors propose modified TRL equations.