GROUND VIBRATIONS PRODUCED BY A 80 IN³ WATER GUN ON THE CHICAGO SANITARY AND SHIP CANAL, LEMONT, ILLINOIS

Since its completion in 1910, the Chicago Sanitary and Ship Canal (CSSC) has become a pathway for invasive species (and potentially Asian carp) to reach the Great Lakes. Currently, an electric barrier is used to prevent Asian carp migration through the canal, but the need for a secondary method is necessary, especially when the electric barrier undergoes maintenance. The underwater Asian carp “cannon” (water gun) provides such a method. Ground movement produced from a 80 in³ water gun within the CSSC was collected using 3-component geophones on the land surface and then analyzed to determine if damage would be caused to structures located along the canal. Vector sum velocity ground movement along the canal wall was as high as 0.28 in/s, which could pose problems for some types of sensitive facilities if they were located near the wall of the canal. However, the dominant frequency of ground motion produced by the water gun is primarily above 40 Hz, so the wave energy should attenuate fairly quickly away from the canal wall, with little disturbance to structures further from the wall.