A portable microtremor observation and analysis system has developed for on-site evaluation of dynamic properties of buildings and ground. The system can evaluate the soil period from the H/V spectrum and the building period and damping using the Random Decrement (RD) method. The software is designed with real-time data processing and easy operation using a graphical user interface (GUI). All of the system components such as sensors, a touch-panel PC, butteries and cables are packed in a carry case. The system is useful especially for easy evaluation of existing buildings with possible resonance which are important for structural design of seismic retrofit.
