碱处理风积砂物理力学试验及加固机理研究  

Physical and mechanical tests on aeolian sand by alkali solution treatment and reinforcement mechanism

作　　者：陈泰徐 李剑武 陈筠 张重重 赵代尧 CHEN Taixu;LI Jianwu;CHEN Jun;ZHANG Chongchong;ZHAO Daiyao(PowerChina Guiyang Survey,Design and Research Institute Co.,Ltd.,Guiyang 550081,China;School of Continuing Education,Guizhou Institute of Technology,Guiyang 550003,China;College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081 [2]贵州理工学院继续教育学院,贵州贵阳550003 [3]贵州大学资源与环境工程学院,贵州贵阳550025

出　　处：《人民长江》2024年第11期229-236,共8页Yangtze River

基　　金：贵州省地质灾害监测预警与决策支持平台建设项目(Z113278);国家自然科学基金项目(52104080)。

摘　　要：为了获取碱液加固风积砂的物理力学特征,通过室内试验,探究了碱液浓度为7%,14%和21%时,养护3,7,14,30 d和60 d后单液加固和双液加固风积砂的物理力学参数变化规律,并简要分析了碱液加固风积砂的作用机理。试验结果表明:(1)碱液的掺入能够提升风积砂的力学性质和水稳性,抗剪强度参数随养护时间的增加逐渐增大,碱液浓度为14%时加固效果最好,养护至60 d时,单液加固试样、双液加固试样的黏聚力和内摩擦角较素土分别提升了48 kPa和10°、66 kPa和9°;(2)双液加固试样强度略高于单液加固试样,但加固的本质仍是碱-土作用,CaCl_(2)的加入能够帮助提升低浓度下加固试样的初期水稳性;(3)碱液加固风积砂的作用机理大致可以分为充填过程、胶结过程和溶解过程。研究成果为风积砂的加固提供了新的方法,也为风积砂分布区的工程建设提供了基础数据和科学指导依据。In order to obtain physical and mechanical characteristics of aeolian sand reinforced with alkali solution,laboratory tests were conducted to explore the changes in physical and mechanical parameters of aeolian sand after being treated with single alkali solution reinforcement and composite alkali solution reinforcement for durations of 3,7,14,30,and 60 days at alkali solution concentrations of 7%,14%,and 21%.The mechanism of how alkali solution reinforces aeolian sand was briefly analyzed.The experimental results show that:(1) The addition of an alkali solution can improve the mechanical properties and water stability of aeolian sand.The shear strength parameters gradually increase with the duration of maintenance.The best reinforcement effect is achieved when the alkali solution concentration is 14%.After 60 days of maintenance,the cohesive force and internal friction angle of the single alkali solution reinforcement samples and the composite alkali solution reinforcement samples have increased by 48 kPa and 10°,and 66 kPa and 9°,respectively,compared to plain soil.(2) The strength of the composite alkali solution reinforcement samples is slightly higher than that of the single alkali solution reinforcement samples,but the essence of the reinforcement is still the alkali-soil interaction.(3) The mechanism of alkali solution reinforcement of aeolian sand can be roughly divided into three phases:the filling phase,the cementation phase,and the dissolution phase.The research findings provide a new method for the reinforcement of aeolian sand and also offer fundamental data and scientific guidance for engineering construction in aeolian areas.

关 键 词：碱液 风积砂 抗剪强度 颗粒粒径 微观结构 

分 类 号：TU446[建筑科学—岩土工程]