Seismic fragility of shallowly buried bias loess tunnels based on vector-valued intensity measures
To quantitatively evaluate the seismic fragility of shallowly buried bias loess tunnels from a probabi-listic perspective,a large number of nonlinear dynamic time calculations were performed on the finite element model of soil-structure interaction using wave methods based on viscoelastic boundaries and incremental dy-namic analysis.Twenty ground motion intensity measures(IMs)were evaluated,and then fragility assess-ments based on scalar-valued IM and vector-valued IMs were subsequently conducted,respectively.The re-sults show that the peak ground velocity(efficiency index ξ=0.15)is the most suitable IM,followed by the velocity spectral intensity(ξ=0.20)and the peak spectral velocity(ξ=0.22).Compared with the scalar-valued IM,the vector-valued IMs are better fitted and can reduce the dispersion of structural damage predic-tion.The effect of the correlation between two IMs needs to be considered to determine the effective range of the established seismic fragility surfaces.Using the scalar-valued IM underestimates or overestimates the ac-tual damage probability of the tunnel.The seismic fragility of tunnels can be evaluated more accurately based on the vector-valued IMs.
万方数据
维普
