Measuring the creep properties of ice in situ

Abstract The pressuremeter can be applied to the measurement of the creep properties of ice. There is reasonable argeement between the results of carefully controlled, constant pressure, pressuremeter tests and the results of constant stress, uniaxial compression tests of equally high calibre. In addition, field tests in the artic in winter have shown that the pressuremeter is a versatile and viable tool for in situ creep tests. Careful calibration of the pressuremeter is essential. For example, the resistance of the rubber membrane of the pressuremeter probe varies not only with how much it is stretched as the probe expands, but also with the temperature of the rubber and the length of time after the start of the test. In the field a wide range of ice temperature may be encountered. Since the length of time that any particular test is run is a function of both the test pressure and the temperature of the ice, temperature has a double role to play in determining the resistance of the membrane at any particular test location. There is merit in equipping the probe with a thermocouple or thermistor to measure the temperature.