Abstract: A key issue in the control,health monitoring,and condition assessment of civil structures is the estimation of structural modal parameters based on measured structural responses.In this paper,a modal parameter identification method for civil structures is proposed based on multiple signal classification-variational mode decomposition (MUSIC-VMD),natural excitation technique (NExT),and direct interpolating (DI).Firstly,the VMD decomposition is optimized by improving the center frequency division process using the MUSIC algorithm,which can decompose the structural vibration signal into a series of single-mode components.Then,NExT is used to obtain the free decay response of the single-mode component.Finally,the damping ratio and natural frequency of the structure are identified using DI and curve fitting.The accuracy and applicability of the proposed modal parameter identification algorithm are verified by the numerical model of a three-layer frame structure.The results show that the proposed algorithm is suitable for modal parameter identification of structures under non-stationary excitation and has good stability and noise immunity.Furthermore,the algorithm is used to deal with the measured non-stationary response of a high-rise building in Hong Kong under Typhoon Neoguri.The modal parameters of the structure are estimated.The presented results are valuable for the identification of structural modal parameters of civil structures under typhoons.