Experimental Research Of The Effect On The Engineering Property Of Expansive Clay By Microorganism

This paper has introducted the enormous influence and danger on the architectural engineering by expansive clay, and also introducted the commonly chemical improvement method which can prevents from the soil disease damaged by the expansive clay. The surface of the earth contain rich active microorganism which have been the important component of the geological environment. According to the analysis of swell-shrinked mechanism of expansive clay, mechanism of chemical improvement and characteristic of microorganism.We have found it is feasible to put microorganism into expansive clay for improving its performance, and there are great economic benefits to the engineering project.The study started from the bloat-contracted property and improvement mechanism of expansive clay. take the suitable microbial strain out of the soil and make solid pharmaceutical seeds. add the microbial pharmaceutical seeds into the soil. After the standard cultivation we have screened all of strain regarding as the free swelling ration and then select 4 strains which make the free swelling ration of the expansive clay decrease obviously. Then they were rescreened by doing direct shear test and other swell-shrinked tests (none pressure expansion test, pressure expansion test, swilling force test, shrinked test ).A strain A₉ ( named temporarily A₉) was picked up according to the test result.In order to get the influence on project properties of expanxive clay by A₉, Depand on some tests we studyed on the change of swell-shrinked and strong characteristic of expansive clay which was added into A₉ for different...