Author
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Hanson, Gregory |
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Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/1/1994 Publication Date: N/A Citation: N/A Interpretive Summary: The effects of compaction and how it changes the behavior of a soil is of concern in many areas of engineering. The ultrasonic immersion testing apparatus was used to transmit a signal at the immersed soil surface and observe changes in the echo characteristics with time. It was observed that the testing apparatus was capable of determining changes in the soil surface elevation with time which is a surface swell phenomenon. Soil swelling is a problem which influences the behavior of structures supported by the soil, the infiltration process, the soil erosion, etc. This type of apparatus has the potential of testing soils in the field and providing relatively quick results. Technical Abstract: An experimental setup for basic measurement of acoustic properties of an immersed soil is described. The test equipment included an ultrasonic instrument, transducer, an immersion water tank, personal computer, and peripheral oscilloscope. The central frequency of the transducer's broadband is 1 MHz. The soil surface and the ultrasonic probe were both immersed in water and separated from one another by a fixed vertical distance. The transmitted signal (pulse) and the received signal (echo) were monitored for changes with time using an oscilloscope. Both the change in time between the pulse and echo, and the change in the amplitude of the signal were monitored over time. The results demonstrated that ultrasonic testing of the soil may be used to give an indication of the soil surface swell due to compaction. |
