摘要
利用反硝化微生物,开展微生物诱导碳酸钙沉淀(MICP)灌浆固化砂土的试验,测定固化前后试样中碳酸钙含量,并通过无侧限抗压强度试验、直剪试验和渗透试验,综合评价反硝化微生物MICP对砂土的固化效果。研究结果表明:反硝化微生物的MICP对砂土固化具有较好效果,通过灌浆试验后的砂土试样,其强度指标、渗透参数和土体的塑性均有所提高;钙离子浓度为0.25 mol/L、配比为1∶2∶2的胶结液对砂土的固化效果最佳,处理后的砂土试样无侧限抗压强度提高了39.2%、抗剪强度提高了53.71%、渗透系数降低了1个数量级;在钙离子浓度相同的胶结液中,提升氮源浓度可有效提升强度参数;在氮源浓度相同的胶结液中,提升钙离子浓度可有效提升强度参数,对试样的渗透性无明显影响。
Denitrifying microorganisms was used to carry out experiments on microbial induced calcium carbonate precipitation(MICP)grouting to solidify sand,and to determine calcium carbonate content in samples before and after curing.Unconstrained compressive strength(UCS)test,direct shear test and penetration test were carried out to comprehensively evaluate the solidification effect of the MICP of denitrifying microorganisms on sand.Research results indicate that the MICP of denitrifying microorganisms has a good effect on the solidification of sand;the Bio grouting test improves the strength parameters of the specimen and the plasticity of the soil;and the cement solution with a calcium ion concentration of 0.5 mol/L and a ratio of 1:2:2 has the best curing effect on sand.The unconfined compressive strength of the treated sand samples increased by 39.2%,the direct shear strength increased by 53.71%,and the permeability coefficient decreased by one order of magnitude.In the cement solution with the same calcium ion concentration,increasing the concentration of the nitrogen source Ca effectively increase the strength parameter;when the concentration of the nitrogen source is the same,increasing the calcium ion concentration can effectively increase the strength parameter,and has no significant effect on the permeability of the sample.
作者
胡其志
刘彻德
庄心善
HU Qizhi;LIU Chede;ZHUANG Xinshan(School of Civil Engin.,Architecture and Environment,Hubei Univ.of Tech.,Wuhan 430068,China)
出处
《湖北工业大学学报》
2021年第4期46-51,共6页
Journal of Hubei University of Technology
基金
国家自然科学基金项目(51609081)。
关键词
反硝化微生物
砂土固化
强度参数
渗透系数
denitrifying microorganism
sand solidification
strength parameter
permeability coefficient
