摘要
作为一种区域性特殊土,红黏土裂隙发育,力学性质较差,而重金属污染将进一步加剧其不稳定性。为探究红黏土在重金属污染下的强度特征,通过XRF分析、直剪试验和抗压试验,分析了污染红黏土中Al_(2)O_(3)、TiO_(2)、K_(2)O等氧化物含量和力学性质与铬离子掺量的关系,并基于分类与回归树(CART)的方法,建模、拟合并预测了红黏土的力学性质随铬离子浓度的变化规律,分析了红黏土中氧化物对其强度的影响。试验结果表明,红黏土的抗剪强度、内摩擦角随铬离子浓度的升高呈下降趋势,而黏聚力随铬离子浓度的升高呈上升趋势,铬离子的引入使红黏土的无侧限抗压强度显著下降。同时CART建模表明土样中的氧化物可对红黏土的强度特性产生影响。
As a regional special soil,the red clay has the characteristics of well-developed cracks and poor mechanical properties.The instability of the compositions in the red clay can be aggravated by the heavy metal(such as Cr3+)contaminations.To investigate the strength characteristics of Cr3+polluted red clay samples,the relationships among the content of oxides(Al2O3,TiO2,K2O,etc.),mechanical properties and the content of Cr3+in contaminated red clay were analyzed through the X-Ray Fluorescence(XRF),the direct shear and the consolidation tests.The variation of mechanical properties with the Cr3+concentration is predicted based on the classification and regression tree(CART)method,and the effect of oxides on the strength of red clay was analyzed by data mining approach.The experimental results show that the shear strength and internal friction angle of the red clay decrease with the increasing of Cr3+concentration,while the cohesion increases.The CART modeling shows that the oxides in the soil can affect the strength characteristics of the red clay.
作者
李焜耀
王雪晴
王永威
LI Kunyao;WANG Xueqing;WANG Yongwei(CCCC Second Harbor Engineering Co.Ltd.,Wuhan 430000;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Wuhan 430000)
出处
《土工基础》
2023年第1期128-133,共6页
Soil Engineering and Foundation
基金
国家自然科学基金面上项目(41772336)。
关键词
污染红黏土
氧化物
强度特性
分类与回归树(CART)
Contaminated Red Clay
Oxide
Strength Characteristics
Classification and Regression Tree(CART)Method
