西安建筑科技大学学报(自然科学版)

考虑到黄土地区经受着季节性冻融循环作用的影响,并随着工业化进程的不断推进,黄土被大量生活污水及工业废水侵入,进而导致土体的内部组构及基本物理力学指标发生改变,诱发土体抗拉特征产生劣化趋势,影响着天然边坡及场地的稳定状态.基于此,本文以铜川地区Q3黄土为研究对象,通过调研取样并人工配置盐酸、硫酸和硝酸的4种不同摩尔浓度的污染液,进行室内冻融循环条件下的酸污染黄土抗拉强度试验研究,探讨了酸污染原状黄土在冻融循环下的抗拉强度演变规律,进一步分析了抗拉特征的耦合劣化结果.结果表明:酸污染原状黄土抗拉强度随着冻融循环次数的增加均呈减小态势,3～5次冻融循环之后黄土抗拉强度趋于基本稳定; 且相同浓度下不同酸污染土的抗拉强度随着冻融循环次数的增加呈现出不同的特征.基于试验数据建立酸侵蚀与冻融循环耦合抗拉强度劣化模型,可为孔隙水污染下的冻融黄土地区的边坡稳定性提供数据支撑及为地质灾害防治设计提供参考.

Considering that the loess area is subject to seasonal freeze-thaw cycles,and with the continuous advancement of industrialization,the loess is invaded by a large amount of domestic sewage and industrial wastewater,which leads to changes in the internal structure and basic physical and mechanical indicators of the soil and the deterioration of the tensile characteristics of the soil,and affects the stability of the natural slope and the site,this study takes Q3 loess in Tongchuan area as the research object,and conducts indoor acid-contaminated loess tensile strength test under the condition of indoor freeze-thaw cycles through investigation,ampling and manual configuration of 4 different molar concentrations of hydrochloric acid,sulfuric acid and nitric acid. Based on the test,the evolution of tensile strength of acid-contaminated undisturbed loess under freeze-thaw cycles is discussed,and the coupling degradation results of tensile characteristics are further analyzed. The results show that the tensile strength of the undisturbed acid-contaminated loess decreases with the increase in the number of freeze-thaw cycles,and the tensile strength of the loess tends to be basically stable after 3 to 5 freeze-thaw cycles. The results also show that the tensile strength of different acid-contaminated soil shows different characteristics with the increase of freeze-thaw cycles under the same concentration. The establishment of a tensile strength degradation model coupled with acid erosion and freeze-thaw cycles based on experimental data can provide data support for slope stability in freeze-thaw loess areas contaminated by pore water and provide reference for geological disaster prevention and control.

引言
1 试验方案
2 结果分析
3 冻融作用下酸污染黄土抗拉强度劣化模型
4 结论

图1 现场取样概况
Fig.1 Field sampling

表1 基本物理性质指标<br/>Tab.1 Basic physical properties

表1 基本物理性质指标
Tab.1 Basic physical properties

图2 颗分曲线<br/>Fig.2 Particle distribution curve

图2 颗分曲线
Fig.2 Particle distribution curve

图3 污染试验装置<br/>Fig.3 Pollution test device

图3 污染试验装置
Fig.3 Pollution test device

图4 卧式抗拉强度测试装置示意图<br/>Fig.4 Schematic diagram of horizontal tensile strength testing device

图4 卧式抗拉强度测试装置示意图
Fig.4 Schematic diagram of horizontal tensile strength testing device

图5 卧式抗拉强度测试装置效果图<br/>Fig.5 Effect diagram of horizontal tensile strength testing device

图5 卧式抗拉强度测试装置效果图
Fig.5 Effect diagram of horizontal tensile strength testing device

图6 冻融循环过程示意图<br/>Fig.6 Schematic diagram of freeze-thaw cycle process

图6 冻融循环过程示意图
Fig.6 Schematic diagram of freeze-thaw cycle process

图7 冻融循环与硫酸污染耦合下黄土拉应力-应变曲线<br/>Fig.7 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and sulfuric acid pollution

图7 冻融循环与硫酸污染耦合下黄土拉应力-应变曲线
Fig.7 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and sulfuric acid pollution

图8 冻融循环与硝酸污染耦合下黄土拉应力-应变曲线<br/>Fig.8 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and nitric acid pollution

图8 冻融循环与硝酸污染耦合下黄土拉应力-应变曲线
Fig.8 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and nitric acid pollution

图9 冻融循环与盐酸污染耦合下黄土拉应力-应变曲线<br/>Fig.9 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and hydrochloric acid pollution

图9 冻融循环与盐酸污染耦合下黄土拉应力-应变曲线
Fig.9 Tension stress-strain curve of loess under the coupling of freeze-thaw cycles and hydrochloric acid pollution

图10 冻融循环下土抗拉强度与酸液浓度的关系<br/>Fig.10 The relationship between soil tensile strength and acid concentration under freeze-thaw cycles

图10 冻融循环下土抗拉强度与酸液浓度的关系
Fig.10 The relationship between soil tensile strength and acid concentration under freeze-thaw cycles

图11 冻融循环次数与污染黄土抗拉强度关系<br/>Fig.11 The relationship between the number of freeze-thaw cycles and the tensile strength of contaminated loess

图11 冻融循环次数与污染黄土抗拉强度关系
Fig.11 The relationship between the number of freeze-thaw cycles and the tensile strength of contaminated loess

表2 拟合参数
Tab.2 Fitting parameters

表3 拟合参数
Tab.3 Fitting parameters

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备注

引言

1 试验方案

2 结果分析

3 冻融作用下酸污染黄土抗拉强度劣化模型

4 结论

期刊信息