Field experiment, results and THM behavior in the Kamaishi mine experiment

Abstract A large-scale in situ experiment was conducted at the Kamaishi mine, Japan. The objectives of this thermo-hydro-mechanical (T-H-M) test were to evaluate the applicability of the engineered barrier technology, to observe near-field-coupled T-H-M phenomena in situ and to increase confidence in coupled T-H-M models. A test pit with a diameter of 1.7 m and a depth of 5.0 m was excavated in the floor of an alcove near a drift in the mine. An electric heater was installed in an annulus with a diameter of 1.04 m and a height of 1.95 m. The heater was placed in the center of the pit and buffer material was compacted around the heater. The duration of the heating phase was 250 days and that of the cooling phase was 180 days. The heater surface was maintained at 100°C during the heating phase. A number of sensors were installed in both the buffer and rock mass during the test. The field experiment leads to a better understanding of the behavior of T-H-M phenomena in the near field.