Experimental research on dynamical properties of rock salt during rising temperature

Because of the special mechanical properties of rock salt can be used for the energy storage and waste (radioactive and toxic wastes) disposal. But one of the properties of deep ground is "high temperature" and the temperature plays very important role of the rock salt mechanical properties, especially rising temperature. Testing with the Yingcheng rock salt during rising temperature (without confining pressure, 20-270 degrees C) using ultrasonic wave. From the experimental data, the velocity of ultrasonic wave, the modulus and the Poisson's ratio of dynamics decrease during rising temperature, but their trend is different. Dynamical elastic modulus decreases fast and the dynamical bulk decreases slowly. The relation of the ultrasonic wave velocity and the dynamical modulus between temperature can be expressed by functions. Both of experimental phenomenon and the data reveals that, the thermal damage and the relative align microcrack density parallel to the axis of specimen evolution with the temperature, but the rate is attenuating when the temperature rising. There is no phenomena indicates the "critical temperature" and damage self-healing due to the temperature.