微生物沉积碳酸钙固化砂土试验研究

发布时间：2018-03-14 20:56

  本文选题：砂土固化　切入点：巴氏芽孢杆菌　出处：《岩土力学》2017年11期 　论文类型：期刊论文

【摘要】：砂土固化对增加砂土强度、减小渗透性极为有利,可提高和改善砂土的力学特性。通过培养基L进行菌种繁殖,研究了不同条件下的细菌生长特性;分析流出液的pH值和Ca~(2+)浓度的内在关系,揭示了固化砂柱的渗透性、无侧限抗压强度变化规律;通过微观结构阐释微生物固化效果,并研究了Ca~(2+)浓度与试样强度的关系。结果表明:2mL细菌母液加入100mL培养液并在30℃、pH为6,150rpm振动速度的条件下最适宜菌种生长;固化过程中,pH值逐渐降低,而Ca~(2+)浓度则增大;采用0.5mol/L胶凝液固化效果较好且固化周期短;固化后砂土颗粒间孔隙被生成的碳酸钙填充;试样渗透性最终降低3~4个数量级;流速越小,固化时间越长,固化效果越好;且固化试样破坏模式都是脆性破坏;采用尿素和醋酸钙混合溶液作为胶凝液,更能提高Ca~(2+)利用率。
[Abstract]:The solidification of sand soil is beneficial to increase the strength and decrease the permeability of sand soil, and can improve the mechanical properties of sand soil. The bacteria growth characteristics under different conditions are studied through the propagation of bacteria in culture medium L. The relationship between pH value of effluent and Ca~(2) concentration is analyzed, the permeability of solidified sand column is revealed, the change rule of unconfined compressive strength is revealed, and the solidification effect of microorganism is explained through microstructure. The relationship between the concentration of Ca~(2 and the strength of the sample was studied. The results showed that the strain growth was most suitable under the condition of adding 100 mL of bacterial mother liquor at 30 鈩，

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