Study on the effectiveness of MICP for highly saline silty soil in Qinghai
Hu Pingshen1 Zhang Wen1,2 Zhao Yuan1 Yang Xiaoxu3,4 Hou Fuxing1 Yuan Yuan1
1. Qinghai University, Xining 810016, China; 2. Qinghai Key Laboratory of Building Energy-Saving Materials and Engineering Safety, Xining 810016, China;
3. The Frist Institute of Resources and Environment Investigation of Henan Province, Zhengzhou 450007, China;
4. Henan Natural Resources Science and Technology Innovation Center (Evaluation of Resource and Environment
Carrying Capacity and Research on Monitoring and Early Warning System), Zhengzhou 450007, China
Abstract：It is a focus and difficult issue in the research of microbial mineralization to discover and utilize natural urease-producing microorganisms for solidification and strengthening of rocks and soils in extreme environments. In this work, a new and natural microorganism of generous urease discovered in highly saline land of Qaidam region in Qinghai province has been experimentally studied on its salt tolerance, mineralization as well as solidification and strengthening of soils. The research results show that the urease activity of the microorganism is maintained between 3.02 U and 5.03 U, accounting for excellent survivability of the microorganism in highly saline soil. Then, after one week of microbial mineralization, solidification and strengthening of highly saline soil, the mechanical strength experiments of soil column are carried out. The averages of results indicate that: the calcium carbonate (mainly consisting of vaterite crystals) content in columns may be increased by 8.11%; the porosity of soil columns may be decreased by 6.12% and the pore size changes from large pores of 4～40 μm to medium pores of 0.4～4 μm, and the pore size distribution range is reduced by 65 to 68 percent; several parameters of basic mechanical strength are improved. The research data indicate that the new microorganism has good tolerance to the highly saline soil in Qinghai and the precipitation of vaterite crystals after microbially induced mineralization can effectively cement the soil particles and enhance the strength of soil. The research provides a method for microbial extraction and mineralized solidification in saline soil, which can be used to explore the effectiveness of microbially induced carbonate precipitation (MICP) in extreme environments.
胡坪伸 张文 赵媛 杨晓旭 侯福星 袁媛. 青海强盐渍粉砂土MICP的有效性探索[J]. 土木工程学报, 2022, 55(3): 65-73.
Hu Pingshen Zhang Wen Zhao Yuan Yang Xiaoxu Hou Fuxing Yuan Yuan. Study on the effectiveness of MICP for highly saline silty soil in Qinghai. 土木工程学报, 2022, 55(3): 65-73.
