在微生物诱导碳酸盐沉积(MICP)理论基础上,以贵州省毕威高速公路的红棕色玄武岩残积土为研究对象,用巴氏芽孢杆菌(Sporosarcina pasteurii)和营养盐(尿素和醋酸钙的混合物)对其进行环保固化处理.通过直剪和固结试验探究微生物固化对玄武岩残积土宏观力学性能的影响;并用X射线衍射、扫描电镜、能谱分析,以及显气孔率分析等检测方法揭示其微细观机理.试验结果表明,玄武岩残积土经微生物固化后,抗剪强度大幅提升,黏聚力c平均提升了193.3%,内摩擦角φ平均提升了12.3%;其压缩性能也得到大幅改善,压缩系数av1-2平均降低了40.1%,压缩模量Es1-2平均提升了41.45%.由X射线衍射分析得知,微生物固化生成了大量的碳酸钙;扫描电镜、能谱分析和显气孔率检测结果显示,微生物固化生成的碳酸钙均匀地填充了土体内部孔隙并将土颗粒胶结在一起,改善了土体的力学性能.%Based on the theory of microbial induced calcite precipitation(MICP),reddish brown basalt residu-al soil as the research object from Biwei highway in Guizhou province was environmentally cured by using Sporosar-cina pasteurii and the nutrient salt(a mixture of urea and calcium acetate). Through direct shear and standard con-solidation tests of basalt residual soil after microbial curing,the purpose is to explore the improvement of the macro mechanical properties of basalt residual soil by microbial curing. Further,X-ray diffraction,scanning electron mi-croscopy,energy spectrum analysis and apparent porosity analysis were used to reveal the microcosmic mechanism. Test results show that the basalt residual soil deposits after biological curing shear strength increases,the cohesion c improved by an average of 193.3%,internal friction angle φ improved by an average of 12.3%;the compression performance has also been greatly improved,compression coefficient av1-2average decrease of 40.1%,compression modulus Es1-2improved by an average of 41.45%;X-ray diffraction analysis showed that microbial curing generates large amounts of calcium carbonate;scanning electron microscope,energy spectrum analysis and apparent porosity rate detection results show calcium carbonate resulting from microbial curing cements soil particles together and fills the internal porosity of the soil,thereby improving the mechanical properties of soil.
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