Recently, we have a very difficulty to repair the leakage of the small old earth dams because of the shortage of suitable impervious soil. This paper represents a improvement method of impervious property of embankment soil in such a dam. This method is the mechanical stabilization of embankment soil obtained from the existing old earth dam need to repair the leakage by adding mud soil in the reservoir.
A series of laboratory tests was performed to investigate the effect of mud soil content on the permeability of a embankment soil stabilized mechanically by adding mud soil. The test results show that the permeability of a mechanical stabilized embankment soil is reduced to less than 1×10^-6cm/sec by the addition of about 10% of mud soil.