多年冻土场地桩基桥梁地震响应不确定性量化分析

In this study, uncertainty quantification of seismic response on pile-supported bridge structure in the permafrost region is carried out based on the finite element numerical model and seismic response characteristics of pile-supported bridge structure in the permafrost region. Firstly, the training samples of surrogate model for pile-supported bridge structure in the permafrost region are constructed using the experimental design method, which is used to generate maximum number of sampling points for uncertainty parameters. A Gaussian process surrogate model is used to simulate input-output relationship for physical processes of pile-supported bridge structure in the permafrost region, and then a reduced order surrogate model is used to perform uncertainty quantification. Seismic response uncertainty of pile-supported bridge structure in the permafrost region is assessed based on statistical variables and variational parameters. The study results showed that: (1) As coefficient of variation (COV) increases from 5% to 30%, time history response of bridge structure the consequent increase correspondingly. The parameter uncertainty of bridge structure has a significant effect on seismic response of pile-supported bridge structure in the permafrost region. (2) As the COV of input parameters for bridge structure are increased, the corresponding COV of seismic response is also increased. This indicated that the COV increase of input parameters for bridge structure directly affects the COV of seismic response. The uncertainty quantification analysis of pile-supported bridge structure in the permafrost region described in this study can provide analytical methods and ideas for the simulation of similar structure.