铁基灌浆对液化粉土动力特性的改性研究  

Improvement of Dynamic Characteristics of Liquefaction Silt Using Iron-based Bio-grouting

作　　者：许朝阳[1] 周锋[1] 孟涛[1] 马耀仁 吕惠[1] 娄可可 

机构地区：[1]扬州大学建筑科学与工程学院,江苏扬州225009

出　　处：《建筑材料学报》2015年第6期1055-1059,共5页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51278446);岩土力学与堤坝工程教育部重点实验室开放基金资助项目(GH201304)

摘　　要：采用铁氧菌对液化粉土灌浆,通过动三轴试验,研究了灌浆粉土动弹性模量和动强度的变化,结果显示灌浆后土体的动弹性模量和动强度均明显提高.采用扫描电子显微镜(SEM)和X射线衍射(XRD)探讨了铁基灌浆对粉土的改性机理,微观分析显示铁氧菌代谢产物中含有碱式磷酸铁络合物,该络合物具有良好的吸附、絮凝效能,可吸附粉土中游离的阳离子及菌丝等多糖产物,最终形成生物黏泥.生物黏泥可填充土粒间孔隙,胶结土体颗粒,从而增加土体的动力抗剪性能.Dynamic modulus and dynamic strength of liquefaction silt bio-grouted by iron-oxidizing bacteria were measured by dynamic triaxial test.Results show that dynamic modulus and dynamic strength were improved obviously after several times of bio-grouting.Scanning electron microscopy（SEM）and X-ray diffraction（XRD）were used to analyze the modification mechanism.Microscopic analyses show that metabolites of iron-oxidizing bacteria contain ferrum oxydatum phosphate complexes which has excellent adsorptivity and flocculation efficiency.The iron-based complexes could adsorb free cations and polysaccharide product in silt,and ultimately deposit into biological slime to fill the voids between soil particles and glue them,thereby increase the dynamic shear behavior of silt.

关 键 词：液化粉土 铁氧菌 生物灌浆 动强度 微观机理 

分 类 号：TU43[建筑科学—岩土工程]