Centrifuge permeameter for unsaturated soils system
View Patent ↗The present invention includes an apparatus, method and centrifuge permeameter system that includes a hydraulic permeameter adapted for use in a centrifuge; and an automated data acquisition system, wherein the centrifuge permeameter non-destructively determines one or more soil characteristics from a sample of granular material such as soil, rock, and concrete when centrifuged.
1. A method of measuring unsaturated soil characteristics comprising the steps of:
placing a soil specimen in a centrifuge permeameter;
applying a centripetal acceleration to the soil specimen;
applying a low-flow rate to at least one portion of the soil specimen during centrifugation;
controlling an outflow boundary condition within the centrifuge permeameter to generate an open-flow boundary condition; and
continuously measuring one or more characteristics of the soil specimen while in flight.
2. The method of claim 1 , wherein the centripetal acceleration applied to the soil specimen is selected to permit a suction and a moisture content to attain equilibrium with an ongoing flow.
3. The method of claim 1 , wherein open-flow and outflow boundary conditions in the centrifuge permeameter are selected to permit the suction and moisture content to attain any value in equilibrium with the ongoing flow processes.
4. The method of claim 1 , wherein the centrifuge permeameter continuously measures the variables relevant to unsaturated fluid flow through soils while the centrifuge is in flight.
5. The method of claim 1 , wherein a centrifuge permeameter instrumentation continuously measures one or more characteristics selected from an unsaturated soil specimens: moisture content, suction temperature, fluid inflow rate, fluid outflow rate, steady-state fluid flow, specimen weight, evaporation and combinations thereof.
6. The method of claim 1 , wherein the one or more characteristics are used in geotechnical engineering, hydrology, agriculture, environmental engineering and petroleum engineering.
7. The method of claim 1 , further comprising the step of applying heat to the soil specimen to induce moisture evaporation while continuously and nondestructively measuring relevant variables such as the change in temperature, relative humidity, and small changes in the weight of a soil specimen while in flight.