About These Projects

This study was commissioned in response to Kamloops residents’ complaints of physical damage to buildings and the resulting loss of property value due to railway induced ground vibration. The CN Rail main line had been recently double-tracked, and the new track was reportedly responsible for increased vibration at houses within a few hundred metres of the right-of-way.

We were retained to assess the extent and perception of vibration disturbances in the community and provide some insight into the source mechanism. The work included wide area monitoring of train induced and ambient ground vibration at over 30 sites using automatic data loggers, and detailed spectrum analysis at a limited number of sites close to the tracks. We also coordinated the design and administration of a simultaneous social survey of the population to determine attitudes and perceptions regarding the trains and vibrations.

The residents’ complaints were confirmed and justified. The new track had about 100 times (20dB) more vibration energy under the same usage conditions as the original track. Ground resonance gave rise to a dominant peak in the vibration spectrum at 6Hz. Soil tests were undertaken in both trackbeds, but proved insufficiently accurate to characterize the vibration conditions. Unusual alluvial soil conditions seemed to play a part in the propogation, and we had recommended further tests in frozen ground conditions, but further soil evaluation was not pursued.

The results of the study, which did fully confirm the extent of the vibration problem, if not the exact soil condition mechanism, were delivered to the citizens’ committee for use in their settlement process.