小样本岩土参数概率分布的正态信息扩散法推断

PROBABILITY DISTRIBUTION OF SMALL SAMPLES OF GEOTECHNICAL PARAMETERS USING NORMAL INFORMATION SPREAD METHOD

提出推断小样本岩土力学参数概率密度函数的正态信息扩散法。该方法基于信息扩散原理,从试验样本和信息论的角度出发,充分利用样本提供的数据信息,而不是先假定成经典的概率分布曲线拟合检验,数学意义和物理意义更加充分和严密。采用精度较高的K-S检验法,从理论上证明所求密度函数的正确性。以广西钦州港地基工程中饱和黏土的多项土工参数作为实测数据,通过检验,表明该方法相对于传统的有限比较法而言,更加接近岩土参数实际的概率分布,为小样本情况下推断岩土参数的概率分布提供一条新途径。

Based on the principle of information spread, normal information spread estimation method（NISEM） is proposed to generate probability density functions of geotechnical parameters with small samples. The new method is distribution-free for no classical theoretical distributions were assumed in advance： and the inference result provides a universal form of probability curves. Then it presented a good solid mathematical and physical performance. Kolmogorov-Smirnov test is used to verify the availability of this method. The results of case study show that the index Dn in NISEM is all smaller than those in the classical finite comparative method（FCM）： and the NISPM function is more accurate and effective than FCM. It shows that the presented method can be used in stochastic reliability analysis of geotechnical engineering.