微生物诱导碳酸钙沉淀技术对花岗岩残积土渗透性的影响规律研究

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中文摘要：用花岗岩残积土填筑的路基具有水稳性差、渗透系数大、易受降雨冲刷等特点.为探讨微生物诱导碳酸钙沉淀(microbial induced calcite precipitation,MICP)技术对花岗岩残积土渗透系数的影响规律及作用机理,测定MICP固化前后重塑花岗岩残积土试样的渗透系数,并对固化前后的试样进行碳酸钙质量分数测定、核磁共振扫描、电镜扫描以及X射线衍射分析.结果表明:1)MICP技术能使花岗岩残积土试样的渗透系数降低两个数量级,且在试验范围内,将各因素按照对渗透系数的影响程度从大到小排列,依次为:胶结液浓度、固化次数、灌注液量.同时,最佳固化条件为灌注液量40 mL、胶结液浓度1.0 mol/L、固化16次.2)固化产生的沉淀填充在花岗岩残积土孔隙中,致使孔隙间的连通性变差,孔隙率下降.总体上,越靠近注入端碳酸钙的质量分数越大,固化效果越好.3)簇状的方解石碳酸钙有效胶结了原本松散的土颗粒,堵塞了土颗粒孔隙间的渗流通道,降低了试样的渗透系数.

外文标题：Study on the effect law of microbial induced calcite precipitation technique on the permeability of granite residual soil

外文摘要：Granite residual soils are characterized by poor water stability,high permeability coefficients,and susceptibility to damage by rainfall scour when used for roadbed filling.To explore the effect of microbial induced calcite precipitation(MICP)technique on the permeability coefficient of granite residual soils and the mechanism of action,the permeability coefficient of remodeled granite residual soil specimens before and after MICP curing was measured,and the calcium carbonate content,nuclear magnetic resonance scan,scanning electron microscope scan and X-ray diffraction analysis were performed on the specimens before and after curing.The results showed that 1)The MICP technique can reduce the permeability coefficient of granite residual soil specimens by two orders of magnitude,in the test range,the order of the influence degree of each factor on the permeability coefficient from large to small is:cement concentration,number of cycles,infusion volume,and the best effect is achieved when the infusion volume is 40 mL,the concentration of cement is 1.0 mol/L and the curing cycle is 16 times.2)The precipitation generated by curing fills in the between the pores of the granite residual soil,resulting in poor connectivity between the pores and a decrease in porosity,and overall the higher the calcium carbonate content near the injection end,the better the curing effect.3)The clustered calcite calcium carbonate effectively cemented the originally loose soil particles,blocked the seepage channels between the soil particles pores,and reduced the permeability coefficient of the specimen.

外文关键词：

granite residual soilpermeability coefficientmicrobial induced calcite precipitation techniquenuclear magnetic resonancescanning electron microscopeX-ray diffraction

作者：

张永杰、唐银港、欧阳健、罗志敏、谭长江

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作者单位：

长沙理工大学土木工程学院,湖南长沙 410114

中交第二航务工程勘察设计院有限公司,湖北武汉 430071

关键词：

花岗岩残积土渗透系数微生物诱导碳酸钙沉淀技术核磁共振扫描电镜 X射线衍射

基金：

国家自然科学基金国家自然科学基金湖南省教育厅重点项目湖南省自然科学基金

项目编号：

518780715217841620A0202022JJ30615

出版年：

2024

DOI：

10.16544/j.cnki.cn43-1494/u.202303142024061981

交通科学与工程

长沙理工大学

交通科学与工程

影响因子：0.444

ISSN：1674-599X

年,卷(期)：2024.40(3)