Simplified parametric modeling to predict vibration attenuation provided by on-grade slabs



When measured vibration amplitudes at the proposed site for a highly sensitive facility exceed the maximum allowable for the sensitive equipment, mitigation measures must be integrated into the design that will reduce the vibration amplitudes to meet the requirements.  Past studies have shown that thick concrete slabs supported on a well-engineered subgrade can effectively reduce ground borne vibrations at certain frequencies.  Predicting the vibration performance of a new slab-on-grade can be a significant challenge, however, as the performance is highly dependent upon the site soil conditions and nature of the vibration sources impacting the location, as well as structural characteristics.  Large and detailed three-dimensional finite element analysis models of the site conditions and proposed structure are often used for this type of assessment, however development of such a model requires significant time and cost to develop accurately.  This presentation discusses a proposed an alternative simplified parametric modeling technique using two-dimensional plane strain modeling.  This technique can be utilized in combination with real-world data to predict the relative benefit of various slab thicknesses and design features such as structural breaks.  The paper will include multiple comparisons between predicted results using this methodology and field measurement results.