Welcome to Geological Journal of China Universities ! Today is
Share:

Geological Journal of China Universities ›› 2023, Vol. 29 ›› Issue (3): 487-496.DOI: 10.16108/j.issn1006-7493.2021114

Previous Articles    

Investigation of Oedometer Test and Mechanism of Soft Soil Improved Using Microbial Composite Material

LIU Qing1,LIN Jun2,XIE Jiamin2, 3*,QIN Pengfei4   

  1. 1. School of Architecture and Engineering, Zhengzhou University of Industrial Technology, Xinzheng 451100, China;
    2. Department of Civil and Environmental Engineering, Shantou University, Shantou 515063, China;
    3. Shantou Polytechnic, Shantou 515078, China;
    4. Zhengzhou University of Railway Vocational Technology School of Railway Engineering, Zhengzhou 451000, China
  • Online:2023-06-20 Published:2023-06-20

Abstract: Microbial induced carbonate precipitation (MICP), as an eco-friendly technology, has been used to improve the mechanical properties of soil. However, it is difficult to apply the MICP to soft soil foundation treatment due to the poor engineering properties. The MICP-sand drain combined with vacuum drainage and MICP-biochar were introduced to the soft soil, and the amount of sand drain and biochar mixing ratio were studied using oedometer test. The microstructures were investigated to reveal the precipitation patterns of calcium carbonate by using SEM and XRD tests. The results showed that porosity ratio decreased with the increase of in number of sand drain and biochar mixing ratio. The coefficient of compressibility and modulus of compression could be improved when the contents of biochar were in a certain range (about 8%). The analysis of calcium carbonate content showed reveal that the amount of calcium carbonate decreased gradually with the increase of in depth, which presented presents non-uniformity of calcium carbonate distribution. Additionally, a large amount of calcium carbonate was observed in the two methods, which were deposited on the contact of soil particles. The crystal type of calcium carbonate was determined as vaterite.

Key words: MICP, soft soil, compression characteristic, biochar, sand drain, foundation treatment

CLC Number: