pH值对桂林红黏土界限含水率的影响及其机理分析

发布时间：2018-01-17 16:15

本文关键词：pH值对桂林红黏土界限含水率的影响及其机理分析　出处：《岩土工程学报》2017年10期 　论文类型：期刊论文

【摘要】：液塑限是影响黏土抗渗透、抗冲切、抗冲刷、抗侵蚀、抗剪切的重要因素之一。为研究红黏土的界限含水率的影响因素及其作用机理,对不同pH值溶液作用下红黏土的液塑限进行测试。试验结果表明,酸性溶液中,随着pH值的减小,红黏土塑限降低,液限与塑性指数则先降低后增大;碱性溶液中,随pH值的增大,塑限、液限均表现为先减小后增大,塑性指数表现为折线变化。经分析表明,传统的扩散层厚度影响因素及双电层理论均不适用于分析不同pH值条件下的桂林红黏土稠度界限。根据相同土的液塑限对应电势一定的原则,在双电层模型的基础上,提出双电层结构模型定性分析红黏土稠度界限的方法。基于传统双电层理论,考虑多种成分溶液作用下,推导了适合桂林红黏土在酸碱液作用下的扩散层厚度计算公式,弥补常规扩散层厚度计算公式仅适用于对称电解质溶液作用的恒定电荷黏土的不足。
[Abstract]:The liquid-plastic limit is one of the important factors affecting the permeability, impact, erosion, erosion and shear resistance of clay. The liquid plastic limit of red clay under the action of different pH solutions was tested. The results show that the plastic limit of red clay decreases with the decrease of pH value, and the liquid limit and plasticity index decrease first and then increase in acid solution. In alkaline solution, with the increase of pH value, the plastic limit and liquid limit decrease first and then increase, and the plastic exponent changes linearly. The traditional influence factors of diffusion layer thickness and the double layer theory are not suitable for analyzing the consistency limit of red clay in Guilin under different pH values. According to the principle that the liquid-plastic limit of the same soil corresponds to a certain potential. Based on the double layer model, a method for qualitative analysis of the consistency limit of red clay is proposed in this paper. Based on the traditional double layer theory, the effect of various components is considered. The formula for calculating the thickness of diffusion layer of red clay in Guilin under the action of acid and alkali solution is derived, which makes up for the deficiency that the conventional formula of thickness of diffusion layer is only applicable to the constant charge clay under the action of symmetric electrolyte solution.
【作者单位】：桂林理工大学土木与建筑工程学院;广西岩土力学与工程重点实验室;
【基金】：国家自然科学基金项目(51169004) 广西自然科学基金创新团队项目(2012GXNSFGA06001) 广西岩土力学与工程重点实验室基金项目(2015-A-01)
【分类号】：TU446
【正文快照】： 红黏土在中国广泛分布,具有黏粒含量高、液塑限高、孔隙比大等特点。液塑性是黏土最基本的物理性质指标之一,反映土的入渗、抗冲、抗蚀、抗剪等情况[1],国内外不少岩土工作者研究了红黏土的液塑性。谭罗荣等[2]对贵阳红黏土扰动失水再恢复后试验,发现红黏土的液塑限产生较大变

【相似文献】