F1离子固化剂加固试验黄土机理及强度特性研究

A Mechanism Study of Trial Loess Reinforced by F1 Ionic Soil Stabilizer on Curing Mechanism and Strength Characteristics

为研究F1离子固化剂对黄土的加固效果和固化机理,利用不同掺量的F1离子固化剂加固试验黄土。从黏土颗粒表面化学入手,利用CBR试验、三轴压缩试验、SEM电镜扫描以及IPP6.0比表面/微孔隙分析软件,对F1离子固化剂加固试验黄土的CBR值、膨胀特性、强度参数和固化前后土体微观结构的变化规律进行了研究。结果表明:F1固化剂可减小土颗粒表面结合水膜的厚度,使土颗粒间的距离(或体积)减小、引力增大,在碾压时形成排列更加紧密、团聚体更大的层状堆叠结构,使得土体的孔隙面积百分比和形态分布分维数减小,土颗粒间的黏结强度、剪切强度、密实度和稳定性增强;在试验黄土中加入0.3 L/m^(3)(最佳掺入比)的F1溶液后,其摩擦角和黏聚力分别增大了1.17倍和1.55倍;F1固化剂通过离子交换作用占据了黏土颗粒表面的阴离子点位,阻碍了其对水分子的吸附,大幅减小了黏土颗粒的膨胀变形;F1固化剂具有绿色环保、加固效果良好等优点,在黄土地区土体填筑工程中有广阔的应用前景。

In order to study the reinforcement effect and curing mechanism of F1 ionic soil stabilizer on the loess,different mixing ratios of F1 ionic soil stabilizer were used to reinforce the trial loess.The CBR values,expansion properties,strength parameters and the variation law of soil microstructure before and after curing of loess reinforced by the F1 ionic soil stabilizer were investigated using CBR test,triaxial compression test,SEM scanning and IPP6.0 specific surface/micropore analysis software from the clay particle surface chemistry.The results show that F1 ionic soil stabilizer can reduce the thickness of bound water film on the surface of soil particles,reduce the distance(or volume)between soil particles,increase the gravitational force,and form a tighter arrangement and larger agglomerate laminated structure when crushed,thus reducing the percentage of pore area and morphological distribution dimension of soil particles,and increasing the adhesion strength,shear strength,compactness and stability between soil particles;after adding 0.3 L/m^(3)(optimum mixture ratio)of F1 ionic soil stabilizer into the trial loess,the friction angle and cohesion increased by 1.36 times and 2.47 times,respectively;F1 ionic soil stabilizer occupies the anion point on the surface of clay particles through ion exchange,which hinders the adsorption of water molecules and greatly reduces the swelling deformation;F1 ionic soil stabilizer has the advantages of green environment and good reinforcement effect,which has broad application prospects in loess filling projects.