不同酸度渗透溶液对重塑黄土渗透特性影响研究  

Permeability Properties of Reshaped Loess in Osmotic Solution of Different Acidities

作　　者：王婷[1] 张爱军[1] 刘宏泰[2] 安鹏[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]机械工业勘察设计研究院,西安710043

出　　处：《长江科学院院报》2013年第2期35-40,共6页Journal of Changjiang River Scientific Research Institute

基　　金：国家自然科学基金项目(50779058);冻土工程国家重点实验室开放基金(SKLFSE200803)

摘　　要：通过对杨凌黄土进行三轴渗透试验和常规渗透试验,分析了不同干密度的重塑黄土分别在pH=7.0的无气纯水及pH=3.0,4.0,5.0的乙酸溶液渗透下渗透系数的变化规律,研究了黄土在含酸渗透水流作用下的劣化性质,为分析黄土在酸溶液渗透作用下强度变化以及黄土构筑物的稳定变化特性提供依据。试验结果表明:①饱和黄土的渗透系数随着干密度的增加而减小。②在一定的干密度下,黄土的渗透系数随围压的增大而减小。③饱和黄土在pH=3.0酸溶液短期渗透下的渗透系数最大,随着酸溶液pH值的增大,渗透系数随之减小,因为酸溶液中的氢离子溶解了黄土中的难溶盐形成了新的渗流通道;而纯水pH=7.0渗透下土样的渗透系数介于pH=3.0和pH=4.0渗透下土样的渗透系数之间,是因为纯水采用的是煮沸过的无气水,相比之下试验配置的酸溶液本身存在少量的气体,从而影响了渗透系数的大小。④渗透系数随时间的增加而出现减小的趋势。试样进行三轴渗透和常规渗透,得出渗透系数都有随时间的延长而减小的规律。Through triaxial permeability tests and conventional permeability tests on reshaped Yangling loess of different dry densities,we analyzed the rules of permeability coefficient variation of the saturated loess respectively in gas-free pure water with pH=7.0,and acetic acid solution with pH=3.0,pH =4.0 and pH=5.0.We also investigated the degradation of loess permeated with acid solution.The research provides basis for analyzing the strength variation and the stability of loess structures permeated with acid solution.The results are as follows：（1） the permeability coefficient of saturated loess decreases with the growth of dry density;（2） with a constant dry density,the permeability coefficient reduces along with the increasing of confining pressure;（3） the largest permeability coefficient appears when the loess is permeated with acid solution with pH=3.0 in short-term,and with the rise of pH value,the permeability coefficient decreases as a result of the dissolving of insoluble salts by hydrogen ions of acid solution,forming new seepage channels.The permeability coefficient of pure water with pH=7.0 is between that of acid solution with pH=3.0 and pH=4.0.It is because that the pure water used in the test is boiled and gas-free,while there is small amount of gas in the acid solution for the test;（4） the permeability coefficient reduces with the increasing of time.

关 键 词：重塑黄土 酸溶液 渗透试验 渗透性 

分 类 号：TV221.2[水利工程—水工结构工程]