GEOL 303 Lecture Notes - Lecture 18: Seismic Wave, Frequency, Ground Vibrations
Document Summary
Base shear - results from love wave side-to-side vibrations. Base of a vertical structure will move abruptly, while its upper portion will tend to remain at rest (because of inertia) Typical of buildings that have soft first stories. Resonance - tendency of a building to oscillate at greater amplitude than its natural oscillation during an earthquake. Period of motion - every building has a natural frequency of back-and-forth sway. Wave period - seismic waves also have a natural period of motion. Time it takes for one seismic wave to pass by. Resonance occurs when the period of motion for the building is in synch with the wave period of the seismic wave. Periods of motion for buildings of different heights. Wave period for seismic waves traveling through different ground materials. Type of material that one builds on is also important. Soft material like soft sand will amplify the vibrations.
