Project:   Development of a Flexible Wall Gradient Ratio Device

PI(s):  Robert D. Holtz

Sponsor:  University of Washington

Objective:   To develop a flexible wall gradient ratio device for testing fine-grained soils and geotextile filters

Research Approach:   The current gradient ratio test (ASTM D 5101) is conducted in a rigid wall permeameter. Consequently, the test is inappropriate for soils with appreciable amounts of fines because of the passage of water between the soil specimen and the permeameter wall. The ASTM test for fine grained soils is the HCR test, but it has a major flaw in that direct determination of the hydraulic conductivity of the soil itself cannot be directly determined in the HCR test. The research aims to develop a gradient ratio test procedure using a flexible wall permeameter.

For more information send e-Mail to: holtz@u.washington.edu