MODAL IDENTIFICATION OF BASE-FIXED MODEL USING STOCHASTIC SUBSPACE METHOD

A two-step system identification is presented to estimate modal properties of a base-fixed model from ambient vibration records on multi-story building with soil-structure interaction (SSI). In the first step output-only stochastic subspace method employed for estimating SSI. second are modified estimates, by using theoretical relations between multi-degree-of-freedom SSI and its equivalent derived in paper. Two examples numerical real-world tests demonstrated show applicability identification.