Abstract:

Through the analysis of the definite and randomness in choosing the settlement modified coefficients by the traditional calculation methods for foundation deformation, the Bayesian statistics was brought forward which was built on the old information and the sample information. The posterior distribution of settlement modified coefficients had been obtained. Conjoining the road bed engineering structure of one passenger dedicated railway, the value range of settlement modified coefficients had been obtained through its posterior distribution. The case study shows the priori probabilities of modified coefficients were estimated to obey uniform distribution in the certain range based on the old information. The settlement modified coefficients had been obtained through analyzing the observed deformation and calculation deformation. Combining the deformation information from the field tests with the prior information, the posterior probabilities of modified coefficients were calculated to obey normal distribution by Bayesian statistics. In addition, the parameters were investigated by estimation of Bayesian confidence interval. According to this red clay, interval estimation of modified coefficients was optimized at [1.0, 1.7]. And probability distribution models of modified coefficients had been obtained under different load conditions.

Key words: settlement, modified coefficients, small sample, Bayesian theory, probability distribution