It simulates the kind of process that occurs in dredging oper-ations, when sediments and water are pumped through pipes. The column studies began in 1992 with a series of tests on glass beads covered with latex particles. These coated beads served as a model for natural sediments. The beads associated with latex particles were subjected to different rates and directions of water flow. The main purpose of these trials was to measure the effect of shear stress on particle detachment when water flows through sediment.
Shear stress refers to the force per unit area that water exerts on the sediment bed.
These experiments strongly supported the Georgia Tech researchers' theoretical predictions. In contrast, the rate of detachment of clay attached to the glass beads fell when the organic concentration in the clay coatings increased. The main difference between natural and simulated sediments was the extent of the detachment rate measured in water of high ionic concentration. The flume used in the Georgia Tech experiments is a tilting channel, six meters long and thirty-eight centimeters wide. It is an effective laboratory tool for simulating how water flows over sediments in rivers or streams.