Source Zones, Recurrence Rates, and Time Histories for Earthquakes Affecting Kentucky

Time histories of hypothetical earthquakes, along with their peak-particle accelerations, and 0 and 5 percent damped response spectra are developed as guidelines for the seismic design of highway structures and bridges within Kentucky. The time histories are derived through the use of random vibration analyses, and take into consideration the probability of earthquakes from nearby seismic zones, the attenuation of ground motions with distance in the Central United States, and the possibility of a random event occurring outside of the generally recognized zones of seismicity in the area. Suggested peak-particle accelerations, time histories, and response spectra are intended for use at sites where the structure is assumed to be situated at the top of a bedrock foundation. For sites underlain by soils, and in particular for those sites underlain by poorly consolidated soils, it is recommended that site specific investigations be conducted by qualified professionals in order to determine the possibilities of frequency-dependent amplification (including resonance), damping, and soil failure when subjected to the suggested time histories. It should be noted that the seismic data is generated at the county seat and not at the county centroid