Experimental Study on Water Retention Properties of Microbially Stabilized Aeolian Sand Soil

Abstract

[Objective] The performance of microbial induced calcium carbonate precipitation (MICP) to stabilize aeolian sand soil was studied in order to providing a theoretical basis for MICP technology in stabilize aeolian sand soil and restoring ecology. [Methods] The microstructure of aeolian sand soil was analyzed by use of scanning electron microscopy and optical microscopy on an aeolian sand soil stabilized with MICP. The test analyzed the basic physical properties and water retention of stabilized specimens. [Results] The aeolian sand soil treated with MICP had calcium carbonate crystals generated between the aeolian sand particles that cemented the sand particles together and solidified the loose aeolian sand into a whole with a certain strength. As curing time increased, the thickness, dry density, and calcium carbonate content of cured aeolian sand gradually increased, the permeability coefficient gradually decreased, the stabilized thickness increased from 3.38 mm to 11.28 mm, the dry density increased from 1.61 g/cm3 for the original sand to 2.05 g/cm3, the calcium carbonate content increased from 8.99% to 13.08%, and the permeability coefficient decreased from 1.06×10-3 cm/s for the original sand to 2.35×10-4 cm/s. When the number of curing treatments was not more than five times, the water retention rate increased with increasing number of curing treatments, and the water retention of the stabilized specimen increased. After more than five curing treatments, water retention decreased. [Conclusion] Aeolian sand soil stabilized by MICP technology can significantly improve the physical and mechanical properties and water retention of aeolian sand soil. Considering this stabilizing effect, water retention, and economics, the best stabilizing treatment time is three times. Thus, we can effectively prevent wind erosion, maintain soil moisture, and facilitate ecological restoration.

Keywords

• microbial mineralization
• micp
• aeolian sand soil
• microstructure
• water retention performance