基于MICP改良黄河泥沙颗粒级配的试验研究

黄河中下游河床内大量沉积黄河泥沙,黄河泥沙存在细度模数小、颗粒级配不良、含泥量高等缺陷,限制了黄河泥沙应用.为改善黄河泥沙的质量和降低应用黄河泥沙带来的工程缺陷,基于泥沙特性和微生物诱导碳酸盐沉积(microbially induced carbonate precipitation,MICP)技术对黄河泥沙进行定量固...

Experimental Study on the Improvement of the Particle Gradation of the Yellow River Silt Based on MICP Technology

A large amount of the Yellow River silt deposits in the middle and lower reaches of the Yellow River The Yellow River silt has defects such as small fineness modulus, poor particle gradation, and high mud content, which limit the application of the Yellow River silt. In order to improve the quality of the Yellow River silt and reduce the engineering defects caused by the application of the Yellow River silt, based on the characteristics of silt and microbial induced carbonate precipitation (micp) technology, the Yellow River silt was quantitatively solidified, SEM) and range analysis were used to study the effect of micp technology on the improvement of Yellow River silt particle size distribution. The results show that the specific gravity of the particles in the size range of 1 mm to 5 mm after micp treatment is 45% higher than that of the first solidified sample, 70% higher than that of the initial sand sample in the same interval, and the contact number of particles in unit volume becomes more and more, showing a multi particle cluster shape; through the immersion test, the dispersion degree of coarse particles and aggregates in the sample is only 5%-10%; the optimum condition is that the particle size distribution of the sample is 5%-10% The improved scheme includes 1:1 bacterial to gum ratio, 1.5mol/l cement concentration, 2:1 urea to calcium source ratio, and CaCl2 as calcium source, in which the cement concentration is the main factor to improve the particle size distribution; most of the CaCO3 crystals generated by mineralization are calcite crystal phase, and a large number of CaCO3 crystals are superimposed to form a bedding structure, and CaCO3 bridge is formed between sand particles, and fine particles are absorbed by cementation, thus increasing the size of silty sand In order to improve the Yellow River silt. Therefore, micp technology can effectively improve the composition and structure of the Yellow River silt, and the research results provide a new idea for improving the Yellow River silt.