膨润土改良柳州红黏土渗透特性及工程应用

The permeability characteristics of bentonite-modified Liuzhou red clay and its engineering application

为了探究膨润土改良红黏土作为人工湖底泥土层的可行性,开展膨润土改良红黏土的室内渗透特性试验研究,确定其最佳掺量,并基于此掺量进行扫描电子显微镜、X射线荧光光谱试验及现场试验,探究改性红黏土的防渗特征与微观结构特性。结果表明:改性红黏土的渗透系数随膨润土掺量的增加而逐渐降低,当掺量大于10%后呈相对稳定趋势;改性红黏土的微观形貌由凝絮状、絮团状基本单元组成,基本单元黏结形成团状聚集体,CaO、SiO_(2)、Fe_(2)O_(3)等氧化物呈增加趋势。原位试验显示,表明采用10%膨润土进行改良,并且防渗层厚度达到40 cm后,能达到防渗要求。

In order to investigate the feasibility of bentonite-modified red clay as the subsoil layer of artificial lake,a series of indoor tests on the permeability characteristics of bentonite-modified red clay were carried out,and the optimal dosage was determined.The scanning electron microscopy,X-ray fluorescence spectroscopy tests and field tests were conducted to investigate the impermeability characteristics and microstructures of the modified red clay.The results show that the permeability of red clay decreases gradually with the increase of bentonite content,and a relatively stable tendency is achieved when the content is greater than 10%.Morphology investigation reveals that the modified red clay is composed of flocculent and flocculent basic units,and the basic units bond to form clumpy aggregates.The oxides such as CaO,SiO 2 and Fe 2O 3 show an increasing trend after modification.In situ test results show that no matter what kind of substrate,the impervious requirements can be satisfied through modification using 10%bentonite at an impervious layer thickness of 40 cm.