Method and probe for measuring hydraulic conductivity of soil
First Claim
1. A method of measuring hydraulic conductivity in soil, said method comprising:
- providing a probe having an electrical potential gradient device for generating an electrical potential gradient and a pressure sensing device for measuring changes in pressure;
inserting the probe into the soil;
measuring a first pressure condition within the soil using the pressure sensing device of the probe;
inducing an electro-osmotic flow in the soil and causing a fluid pressure gradient by applying an electrical potential gradient to the soil using the electrical potential gradient device of the probe for an elapsed period of time;
measuring a second pressure condition within the soil using the pressure sensing device of the probe;
removing the application of the electrical potential gradient to the soil using the electrical potential gradient device of the probe after the elapsed period of time has expired;
measuring a duration for condition of the soil to return from the second pressure condition to a pressure approaching the first pressure condition; and
calculating hydraulic conductivity based upon a prescribed relationship of hydraulic conductivity and the measured duration.
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Accused Products
Abstract
Agricultural waste lagoons are the predominant method currently utilized to contain large quantities of livestock by-products such as manure. Clay liners are the most common materials used to line the bottom of storage lagoons in order to prevent waste effluent seepage. Clay liners are an economical lining material and have a hydraulic conductivity of less than 1×10−7 cm/s. Proper containment of waste in storage lagoons is critical to avoid the implications of local groundwater contamination. A hydraulic conductivity probe was designed to alleviate the negative aspects of the current methods used to determine hydraulic conductivity. The probe includes a housing for insertion into the ground, electrical potential gradient means for generating an electrical potential gradient in the ground and pressure sensing means for measuring changes in pressure in the ground.
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Citations
28 Claims
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1. A method of measuring hydraulic conductivity in soil, said method comprising:
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providing a probe having an electrical potential gradient device for generating an electrical potential gradient and a pressure sensing device for measuring changes in pressure; inserting the probe into the soil; measuring a first pressure condition within the soil using the pressure sensing device of the probe; inducing an electro-osmotic flow in the soil and causing a fluid pressure gradient by applying an electrical potential gradient to the soil using the electrical potential gradient device of the probe for an elapsed period of time; measuring a second pressure condition within the soil using the pressure sensing device of the probe; removing the application of the electrical potential gradient to the soil using the electrical potential gradient device of the probe after the elapsed period of time has expired; measuring a duration for condition of the soil to return from the second pressure condition to a pressure approaching the first pressure condition; and calculating hydraulic conductivity based upon a prescribed relationship of hydraulic conductivity and the measured duration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of measuring hydraulic conductivity in soil, said method comprising:
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providing a probe having an electrical potential gradient device for generating an electrical potential gradient and a pressure sensing device for measuring changes in pressure; providing a probe insertion tube for slidably receiving the probe therethrough; inserting the probe insertion tube into the soil prior to insertion of the probe; inserting the probe into the soil by inserting the probe through the probe insertion tool; measuring a first pressure condition within the soil using the pressure sensing device of the probe; applying an electrical potential gradient to the soil using the electrical potential gradient device of the probe for an elapsed period of time; measuring a second pressure condition within the soil using the pressure sensing device of the probe; removing the application of the electrical potential gradient to the soil using the electrical potential gradient device of the probe after the elapsed period of time has expired; measuring a duration for condition of the soil to return from the second pressure condition to a pressure approaching the first pressure condition; calculating hydraulic conductivity based upon a prescribed relationship of hydraulic conductivity and the measured duration. removing the probe from the probe insertion tube subsequent to measurement of the first and second pressure conditions; introducing soil sealing material through the probe insertion tube to fill a cavity in the soil formed by the probe; and removing the probe insertion tube from the soil. - View Dependent Claims (17)
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18. A probe for measuring hydraulic conductivity in soils, the probe comprising:
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a housing being suitably shaped for insertion into the ground, the housing including side walls extending in a longitudinal direction between an exposed end of the housing and a pointed end cap at a soil penetrating end of the housing, the pointed end cap being insulated with respect to the side walls of the housing; an electrical potential gradient device for generating an electrical potential gradient in the ground surrounding the housing, the electrical potential gradient device comprising; a first electrode coupled to the pointed end cap at the soil penetrating end of the housing and a second electrode coupled to side walls of the housing in which the first and second electrodes are insulated from one another at spaced locations from one another in the longitudinal direction of the housing; and an electrical power supply coupled between the first and second electrodes; and a pressure sensing device for measuring changes in pressure in porewater within the ground. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification