On Estimation of Dynamic Characteristics of Building Structure from Micro-Tremors

Output response of bui1ding structure due to micro-tremors is considered as random process，and then statistical method of stationary time sereis analysis can be applied to estimation of dynamic characteristics of bui1ding structure. In this paper，effect of optimum lag window and assumption of input spectrum are discussed numerically in evaluation procedure of output spectral density， from which dynamic characteristics is determined. To effect of lag window， numerical computation is carried out with following four kinds of lag windows; DO NOTHING， BARTLETT， HANNING， HAMMING. Inf1uence of pattern of input spectrum to estimation is analyzed，with regard to two cases of band limited white spectrum and decline power spectrum. As a result，it is appointed that estimation value is not severely affected by selection of lag window and assumption of input characteristics