Experimental Research on Chemical Modification of Expansive Soil and Its Application in Slope Engineering

The expansive soil slope improved through chemical methods has the broad prospect for development.The octadecyl-trimethyl ammonium chloride and potassium chloride were choosen to improve the expansive soil especially the expansive soil slope based on the swell-shrink mechanism,and the modification mechanism was stated on the microscopic level.The free swelling rate test and unconfined compression strength test on expansive soil were conducted.The test results show that the expansion of the modified soil would be considerably restrained,the water-stability would also be improved,and the sample would not be damaged when soaked into water.The grain size analysis test and the centrifugal test show that the volume-to-surface ratio would be reduced,the water-soil interaction would be weakened,and the hygroscopic moisture content would also be decreased.The simulative penetration improvement test shows that the expansive soil in a certain depth range could be effectively improved after the sprinkling of improver.