SBIR-STTR Award

Measurement of the hydraulic characteristics of soils and engineered materials is of great importance to U.S. industry and agriculture. Existing techniques of measuring these properties employ manual airentry systems which are capable of establishing only Fred boundary pressure conditions. We present an innovative design which allows fully automated infiltration measurement with time-controlled pressure and/or flux boundary conditions. The major advancement is accomplished by replacing the complex triple-tube-marriotte-bottle system used in presently available devices with a single $15 electronic air valve. The valve is operated by a data acquisition and control unit in response to readings from two pressure transducers. This new device can be used in the field for positive and negative pressure experiments, and as a precision supply device for laboratory experiments on soil cores. Preliminary data is presented that suggests the system is viable. The objectives of this proposal are to demonstrate feasibility in application with real soils and determine the degree of precision which can be obtained with this system in both controlled pressure and flux conditions. Our ultimate goal is to produce a device which is more precise and flexible than present technology and usable by people without special training in soil hydraulics.Applications:The outcome of Phase I will be an answer on the feasibility of creating a commercially viable fully automated infiltration measurement system that measures saturated and unsaturated hydraulic parameters with little or no user intervention during the measurement. The accurate and automated determination of soil hydraulic parameters offers benefits to the following applications: drainage studies for septic tanks, selection of building sites; seepage determination of ponds, canals, dams and hazardous waste dumps; groundwater contamination studies, irrigation management, and others. Our goal is to make feasible several measurements which have until now been avoided due to a lack of practical tools.

The ability to measure the hydraulic infiltration and permeability properties of soils and various geotechnical materials is a growing need in science and engineering with the increased emphasis on groundwater quality protection, water conservation, erosion control and other water relevant issues. These measurements have classically been performed on soils using various forms of infiltrometer and permeameter technologies. Examples, include tension infiltrometers and constant head permeameters for measuring hydraulic conductivity under unsaturated and saturated conditions, respectively. Most of these existing instruments provide a constant pressure or tension at the soil interface with the infiltration characteristics measured over time. These existing technologies require a large amount of manual user intervention from a small select group of highly qualified scientific personnel to perform the measurements due to the lack of automated pressure control as well as the absence of embedded interpretation software.This SBIR project is undertaking the research and development of an automated infiltrometer design that controls the pressure at the soil interface with high precision at user-settable profiles vs. time. Phase I has demonstrated the feasibility of developing such a product and Phase II will involve the development of the technology. This improved tool offers great flexibility and ease of use.

Anticipated Results/Potential Commercial Applications of Research:
The anticipated results of this product is a very straight forward, easy to use infiltration measurement system that will be useable and understandable by a much larger base of users. The automation and promise of embedded interpretation software offer the first real promise of a complete hydraulic property measurement system that can measure the parameters directly in the field without the need of highly qualified personnel to interpret the results or manually operate the product the product. This offers the potential of extending this type of product into the mainstream hydraulic property measurement markets of both soils and geotechnical materials.