Experience in foundations includes application of Itasca’s software to problems where existing techniques are either unavailable or are known to be inaccurate. For example, FLAC3D was used to determine the subgrade reaction modulus for a thick concrete slab placed over fill with varying thickness. In another case, an industrial machine produced a cyclic vibration. The effect of the vibration on nearby foundations supporting other machinery was studied dynamically by applying the cyclic loading to one location and measuring the vibration levels at other locations. A similar study was performed to evaluate the dynamic effects on nearby buildings due to trains running in subway tunnels at a shallow depth. Various remedial measures were evaluated numerically before selecting the recommended solution.