Efficiency of Trenches on Vibration Isolation under Time Dependent Loads

Results from some parametric studies were presented to assess the dynamic response of soil surface and to investigate the effectiveness of trenches in reducing vibrations due to time dependent loads acting vertically on the soil surface for two-dimensional (2-D) problems by coupling finite and infinite elements. The effects of various parameters such as height of the trench, infill materials and location of the trench on screening efficiency have been investigated. It is concluded that using open or in-filled trenches can reduce the vibrations of a structure; especially the use of an open trench provides better isolation than using an in-filled trench. Efficiency of isolation increases with height of trench. The trench height has appeared as the most important parameter on screening vibrations. The location of the trench is also effective on dynamic response of soil surface. Coupling finite and infinite elements can be easily applied to study the isolation problems.