This is the first time I have heard of this type of consolidation/permeability testing. I won’t try to summarize myself, here’s a bit of a description from their newsletter:
Hydraulic consolidation cells, a.k.a. Rowe-Braden consolidation cells, can be used to carry out a variety of vertical and radial consolidation and permeability tests. A main advantage is that the vertical stress is applied by a water-filled pressurized rubber membrane in contact with the top of the test specimen. Therefore, large diameter soil samples can be tested without the use of dead weights, mechanical or pneumatic loading frames or compression machines. The relatively large sample diameter enables the effect of soil fabric (stratigraphy, varves, fissures, bedding planes) on drainage to be examined. Permeability in either vertical or horizontal direction can be reliably determined along with values of void ratio, pore pressure and effective stress to closely simulate field conditions.