膨胀土判别与分类的Bayes判别分析法

基于Bayes判别分析法以建立膨胀土判别与胀缩等级分类的Bayes判别分析模型. 模型 选用液限，胀缩总率，塑性指数，天然含水率，自由膨胀率等5个指标作为判别因子；将膨 胀土的胀缩性分为极强、强、中、弱4个等级并作为Bayes判别分析的4个正态总体；以训 练样本建立Bayes线性判别函数，以该函数计算待判样品的Bayes判别函数值，以最大值对 应的总体作为样品的归属；以刀切法对判别准则进行评价. 研究表明，该模型以刀切法计算 的误判率为13.3%.

BAYES DISCRIMINANT ANALYSIS FOR THE IDENTIFICATION AND CLASSIFICATION OF EXPANSIVE SOIL

Based on the principle of Bayes discriminant analysis,a Bayes discriminant model for evaluating expansive soil is established.Five indexes,including the liquid limit,the overall rate of expansion and contrac- tion,plastic index,moisture content,free expansion rate,are selected as the factors for synthetic evaluation of expansive soil.The shrink and expansion is divided into four grades as four normal populations in Bayes discriminant analysis.Bayes discriminant functions obtained through training a set of expansive soil samples are used to compute the Bayes function values of the evaluating samples,and the maximal function value is used to judge which population the evaluating sample belongs to.The usefulness of the proposed model is verified by Jackknife method.The study shows that the average prediction accuracy is 13.3%.