基于化学分散机制理论对分散性土的改性试验研究  

Experimental Study on Modification of Dispersed Soil based on Chemical Dispersion Mechanism Theory

作　　者：何静斌 杨凌云[1] 常玉鹏 崔家全 贺晶晶 陈楠[1] 崔家铭 HE Jingbin;YANG Lingyun;CHANG Yupeng;CUI Jiaquan;HE Jingjing;CHEN Nan;CUI Jiaming(PowerChina Northwest Engineering Corporation Limited,Xi'an 710065,China;School of Water Conservancy and Hydroelectric Power,HUE,Handan 056001,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065 [2]河北工程大学水利水电学院,河北邯郸056001

出　　处：《西北水电》2024年第4期33-37,共5页Northwest Hydropower

基　　金：国家自然科学基金项目(5207090694).

摘　　要：分散性土在中国西北、东北地区分布广泛,受环境限制许多新建水利水电工程不得不选择分散性土作为坝体心墙的防渗土料,由于它的抗冲蚀能力很低,容易造成堤坝管涌、路基失稳等现象,因此如何改善其分散性成为了当下水利水电工程建设中亟待解决的问题。为了探明分散性土改性效果及作用机理,基于化学分散机制理论,对西藏地区某水利工程的分散性防渗土料分别进行了掺配MgO、CaO、MgCl_(2)、CaCl_(2)4种改性剂的改性试验研究,掺配含量范围为0.15%~1.50%。结果表明:各含量的MgO基本不具备改性功能,当CaO、MgCl_(2)、CaCl_(2)3种改性材料掺量达1%后,针孔试验、碎块试验、孔隙水阳离子试验结果均显示为非分散性土,改性效果较好。综合考虑现场施工的可操作性、经济性及对土体性质结构的影响等因素,建议现场采用掺量1%的MgCl_(2)对分散性防渗土料进行改性处理。Dispersed soil is widely distributed in northwest and northeast China.Due to environmental restrictions,many new water conservancy and hydropower projects have to choose dispersed soil as the anti-seepage material for the dam core wall.Due to its low anti-erosion ability,it is easy to cause dam pipe surge and roadbed instability.Therefore,how to improve its dispersion has become an urgent problem to be solved in the current water conservancy and hydropower project construction.In order to find out the modification effect and mechanism of dispersed soil,based on the theory of chemical dispersion mechanism,the modified test of MgO,CaO,MgCl_(2) and CaCl_(2) is carried out on the dispersed anti-seepage soil of a water conservancy project in Tibet,and the modified content range of the soil is 0.15%~1.50%.The results show that MgO at various contents basically has no modification function.When the content of CaO,MgCl_(2) and CaCl_(2) reaches 1%,the results of pinhole test,fragment test and pore water cation test all show that it is modified to non-dispersed soil,and the modification effect is favorable.Considering the operability,economy and influence of soil properties and structure of on-site construction,it is recommended to use 1%MgCl_(2) to modify the dispersed anti-seepage soil on site.

关 键 词：分散性土 改性试验 化学分散机制 针孔试验 碎块试验 孔隙水阳离子试验 

分 类 号：TU43[建筑科学—岩土工程]