FINITE-ELEMENT SIMULATION OF THE HYDRAULIC PERMEABILITY PROPERTIES OF THE MICROBIAL MODIFIED SAND COLUMN

Biogrout method is a new kind of method for soil reinforcement，which is based on the microbial mineralization． In the process，the bacterial cells and the nutrient solution are grouted into the porous material， inducing the calcium carbonate precipitation which forms cementation among particles，thus improving the mechanical and hydraulic properties of the treated material． This paper mainly investigated the modification in the hydraulic properties of the biochemical treated sand column，including the porosity and permeability changing along the whole column，through the one dimensional finite-element simulation of grouting process． The simulated results were compared with the test results． The result showed that biogrout could decrease the porosity and permeability coefficient of the treated sand column to a certain extent，but with a significant inhomogeneity． And the simulated changing trends in porosity showed a good agreement with the test，but there was a big difference between the simulation and the experiment of the change in the permeability coefficient．