Abstract:

There are many in-situ remediation technologies for the total petroleum hydrocarbon (TPH) contaminated soils, investigation of potential effects of three remediation technologies on the engineering properties of petroleum hydrocarbon-contaminated silty sand is however limited. Laboratory tests have been conducted to examine variations of physical and mechanical properties of the contaminated soils before and after remediation. The test results show that the engineering properties of the contaminated soils have been largely improved after a thermal desorption remediation, with water content and compressibility decreasing as well as average pore size and shear strength and permeability increasing. After chemical oxidation remediation, the engineering characteristics of the soil become relatively poor, and the impact of thermal desorption coupled with chemical oxidation on the engineering characteristics of the soil is between the two. It is also found that the mechanical properties of the contaminated soils are well correlated with its concentration of residual petroleum hydrocarbon and water content, and it is not affected by remediation technologies. Based on the test results, normalized equations are proposed to estimate the mechanical properties of the contaminated soils before and after remediation. The findings are expected to be useful to choose a reasonable remediation technology as well as foundation design.

Key words: contaminated soils, petroleum hydrocarbon C6-C9, remediation technology, engineering properties