结合微生物对岩土工程特性影响的研究现状，选取黑曲霉、放射型土壤杆菌及地衣芽孢杆菌3株菌种，首先通过压缩试验研究了不同微生物菌种及其培养液掺入土样后对土样固结特性的影响情况，然后借助矿物和化学成分分析及土粒比表面积测定等手段，初步探索微生物改良吹填土机制。研究表明，掺入微生物菌种及其培养液后土样的压缩系数av1-2均有降低，压缩模量Es1-2均有增加，最大降幅和升幅分别为29%和37%；土样的矿物成分没有改变；土中高价阳离子明显减少，但这不是造成土体压缩特性变化的主因；掺入放射型土壤杆菌、地衣芽孢杆菌后土样土粒的比表面积分别增大到1.49倍、1.45倍，菌株改变了土颗粒间的连接状态，从而导致土体颗粒的增多或者土体结构的变化。

This paper is about land reclamation with hydraulic fill. The hydraulic fill is treated with microorganism for enhancing its compressibility. It selects Aspergillus niger, Agrobacterium radiobacter and Bacillus licheniformis to do the experimental study. First, the changes of the consolidation characteristics of fill soil are examined after different microbial strains and culture mediums are added in the soil through consolidation test. Then some measures including determination of specific surface area of soil particles, chemical composition analysis and mineral composition analysis are applied to exploring the mechanism of modified hydraulic fill with microorganisms. The results show that: after the incorporation of microbial strains and culture medium mixed with the soil samples, the compression factors av1-2 of the soil samples show a decreasing trend and the largest drop is 29%; the compression moduli Es1-2 show an increasing trend and the biggest gain is 37%. The mineral composition of soil samples is essentially the same. The high valent cation content reduces significantly, which isn’t the main reason of the change of soil compression feature. The specific surface area of soil particles added with Agrobacterium radiobacter increases 49%. The specific surface area of soil particles added with Bacillus licheniformis increases 45%. The reason is that strains change the connection state of soil particles, and then lead to increasing of soil particles or the change of soil structure.