Basic Study on the Frost Heave Pressure of Rocks: Dependence of the Maximum Frost Heave Pressure on Temperature

In this study, we attempted to measure frost heave pressure, i.e., the pressure that develops in the heat-flow direction when rocks are subject to frost heave and ice lenses grow. We used two kinds of rock samples: one was Ohya tuff, whose frost heave was already known to be high, and the other was Kimachi sandstone, whose frost heave was lower than that of the former. Ohya tuff and Kimachi sandstone, in which the occurrence of frost heave has previously been confirmed, were used as specimens. To conduct the experiment, we made original frost heave experiment equipment that was combined with a reaction frame and a load cell. The test results clearly showed that the maximum frost heave pressure did not depend on the kind of rock and was proportional to the temperature gradient. In addition, we clarified that the speed of the increase in pressure was proportional to the frost heave rate — the growth rate of the ice lens.