采用2次注入菌液方式，制备不同浓度营养盐处理的微生物诱导碳酸钙沉淀（MICP）胶结砂样。通过固结排水三轴试验和碳酸钙定量化学试验测定试样强度参数及碳酸钙（CaCO3）含量，分析了营养盐浓度对胶结砂物理力学特性的影响及碳酸钙沉淀量试样强度指标间的关系。结果表明，同等反应时间、同等体积营养盐溶液条件下，随着营养盐浓度的提高试样强度逐渐升高，且达到一定峰值后再下降；碳酸钙晶体分布形态较好条件下，变形模量随着试样干密度的增加而增加；碳酸钙晶体分布形态和沉淀含量共同影响MICP试样强度的提高，试验中0.5 M试样强度提高效果最好，碳酸钙含量、黏聚力、内摩擦角分别为6.03%、46.9 kPa和41.31°。

Preparation of microbial induction of calcium carbonate precipitation(MICP) cemented sand samples injected twice bacteria solution with different concentrations of nutrient salt treatment, triaxial tests and CaCO3 quantitative chemical tests are conducted on cemented sand to analyze the effect of nutrient concentration on the mechanical properties of cemented sand and the relationship between the calcium carbonate content and the strength indexes of calcium carbonate precipitation samples. The results show that: The strength of the sample increase gradually with the increase of nutrient concentration; and then decrease after reaching a certain peak value under the same reaction time and volume of nutrient solution. The deformation modulus increases with the increase of dry density of samples under the condition of good distribution of calcium carbonate crystals. The distribution of calcium carbonate crystals and calcium carbonate content affected the increase of MICP specimen strength. The strength of 0.5 M is the highest in the experiment, and the content of calcium carbonate, cohesion and internal friction angle are 6.03%, 46.9 kPa and 41.31° respectively.