Abstract
One of the most important parts that determine the safety of a waste disposal site is the imperviouslayer. Recently, fail-safe impervious layer consisted of bentonite-soil mixture has been widly used. Thepermeability performance of an impervious layer should be evaluated by using its coefficient of permeability. However, it has become a common practice in-situly that dencity or water content, characterisitics indirectly correlated to the coefficient of permeability, is used to evaluate the coefficient of permeability performance rather than the coefficient itself. To accurately assess the safety of a waste disposal site, it is considered that the coeffisient of permeability is directly used to control the quality. Due to this reason, a simple field test apparatus was developed. A direct measurement technique for the coefficient of permeability by using this test apparatus is discussed in this paper.
