微生物诱导碳酸钙沉积联合黄原胶加固砂土室内试验研究

Laboratory Test on Microbially Induced Carbonate Precipitation Combined with Xanthan Gum for Sand Reinforcement

微生物诱导碳酸钙沉积加固法(MICP法)和黄原胶均能够有效地改善砂土的力学特性。然而,一次微生物固化处理在砂土中产生的碳酸钙含量往往较少,对砂土力学特性的增强作用有限。黄原胶对土体的加固效果受水流的影响较大。因此,本文通过无侧限单轴压缩试验,探究微生物诱导碳酸钙沉积联合黄原胶对砂土力学特性的加固效果。在无侧限单轴压缩试验中,微生物诱导碳酸钙沉积联合黄原胶固化砂的无侧限抗压强度,高于微生物诱导碳酸钙沉积固化砂或黄原胶固化砂的强度,并且随着处理液中黄原胶浓度的增加,微生物诱导碳酸钙沉积联合黄原胶固化砂的无侧限抗压强度增大。

Both microbially induced carbonate precipitation(MICP)and Xanthan gum can effectively improve the mechanical properties of sand.However,the amount of calcium carbonate produced by a single MICP treatment in the sand is usually small,and the improvement of the mechanical properties of the sand is limited.The improvement effect of Xanthan gum on soil is greatly affected by water flow.Therefore,in this paper,the unconfined uniaxial compression tests were conducted to explore the improvement effect of microbially induced carbonate precipitation combined with Xanthan gum(MICP-XG)on the mechanical properties of sand.In the unconfined uniaxial compression test,the unconfined compressive strength of the MICP-XG treated sand is higher than that of MICP treated sand or Xanthan gum treated sand,and the unconfined compressive strength of the MICP-XG treated sand increases with the increase of the concentration of Xanthan gum.