瓜尔豆胶固化粉质黏土工程特性研究

Study on Engineering Characteristics of Silty Clay Solidified by Guar Gum

摘要: 粉质黏土的高压缩性和低强度特性，限制了其在重大工程项目中的应用。为了克服这些限制，采用生物聚合物——瓜尔豆胶固化粉质粘土。文章以某工地粉质黏土为研究对象，开展渗透试验、三轴不固结不排水剪切试验及崩解试验，深入探讨瓜尔豆胶固化粉质黏土的工程特性，结果表明：在围压相同的情况下，随着瓜尔豆胶掺量的增加，粘土试样的渗透系数逐渐降低，在100 kPa时，1.0%掺量的瓜尔豆胶固化土样的渗透系数为0.25 × 10⁻⁵cm·s⁻¹，相应的渗透系数降低了53.2%；未添加瓜尔豆胶的粉质粘土峰值强度较低，随着围压的增加，峰值强度逐渐增大。围压在100 kPa，瓜尔豆胶的掺量在1.0%时，峰值强度达到最大为316.7 kPa；未固化粉质粘土崩解量呈线性增长趋势，在300 s内全部崩解，经瓜尔豆胶固化粉质粘土在浸水崩解30分钟后，最终崩解量为5.9%，表明瓜尔豆胶固化后的粉质粘土保存有较好的抗崩解性；未固化粉质粘土的土颗粒排列比较松散，形成的孔隙较多。瓜尔豆胶固化后粉质粘土孔隙通道数量明显减小，瓜尔豆胶在土颗粒之间起到良好的胶结效果。

Abstract: The high compressibility and low strength of silty clay limit its application in major engineering projects. To overcome these limitations, silty clay is solidified with a biopolymer—guar gum. Taking silty clay at a construction site as the research object, this paper carried out permeability tests, triaxial unconsolidated undrained shear tests, and disintegration tests to further explore the engineering characteristics of guar gum solidified silty clay. The results show that under the same confining pressure, with the increase of guar gum content, the permeability coefficient of clay samples decreased gradually. At 100 kPa, the permeability coefficient of 1.0% guar gum solidified soil sample was 0.25 × 10⁻⁵ cm∙s⁻¹, and the corresponding permeability coefficient decreased by 53.2%. The peak strength of silty clay without guar gum is low, and the peak strength increases gradually with the increase of confining pressure. When the confining pressure is 100 kPa and the dosage of guar gum is 1.0%, the peak strength reaches a maximum of 316.7 kPa. The disintegration of uncured silty clay showed a linear increase trend, and all the silty clay disintegrated within 300 s. The disintegration of silty clay cured by guar gum was 5.9% after 30 minutes of immersion, indicating that the silty clay cured by guar gum had good disintegration resistance. The arrangement of soil particles of unsolidified silty clay is relatively loose, and more pores are formed. After curing guar gum, the number of pore channels of silty clay decreased significantly, and guar gum had a good cementation effect among soil particles.