纤维红黏土强度的正交试验及多元非线性回归分析

Orthogonal test and multivariate nonlinear regression analyses of strength of the fiber red clay

纤维长度、纤维掺量、含水率和干密度是纤维红黏土强度的主要影响因素,采用正交试验设计方法,研究多因素耦合作用对纤维红黏土抗剪强度指标c,φ的影响,通过对试验结果进行极差、方差分析,确定了c,φ的最优制备工艺及各影响因素的显著性大小。基于多元非线性回归理论,应用SPSS软件建立了多因素与纤维红黏土c,φ的多元非线性回归模型。试验和分析结果表明:4个因素对纤维土c,φ的影响主次顺序均为:含水率>干密度>纤维掺量>纤维长度,其中含水率对c影响显著,干密度与纤维掺量对c有一定的影响,而φ受含水率影响明显,其它因素对其影响不明显,各因素水平的改变对c的影响程度大于对φ的影响。对c,φ的多元非线性回归模型验证发现,c,φ模型的相关系数较高、显著性较强、且预测值与实际值之间线性关系明显,确定了模型的可靠性。研究成果为进一步研究纤维改善红黏土的工程特性、固化机理具重要指导意义。

Fiber length,fiber content,water content and dry density are the main influencing factors of the strength of fiber red clay. The orthogonal experimental design method is used to study the effect of multifactor coupling on the shear strength indexes c and φ of the fiber red clay. The test results are analyzed by the range analysis and variance analysis,and the optimal preparation process of c and φ and the significance of each influencing factor are determined. Based on the multivariate nonlinear regression theory,a multivariate nonlinear regression model of multi-factor for c and φ of the fiber red clay is established by sing the SPSS software. The experimental and analytical results show that the main order of the influence of four factors on the values of c and φ of the fiber soil is: water content > dry density > fiber content > fiber length,in which the water content has a significant effect on c,dry density and fiber content. Dry density and fiber content have a certain effect on c,φ is obviously affected by water content and other factors have no obvious influence on φ.The change of level of each factor affects c more than φ. The multivariate nonlinear regression model of c andφ shows that the correlation coefficients of c and φ models are higher and more significant,and the linear relationship between the predicted and actual values is obvious,and the reliability of the model is determined.The research results are of important guiding significance for further research on the engineering characteristics and curing mechanism of the fiber-modified red clay.