STUDY OF PHYSICO-MECHANICAL CHARACTERISTICS OF ROCK UNDER DIFFERENT FROZEN-THAWED CIRCLE TEMPERATURE RANGE AND ITS ENGINEERING APPLICATION

The physico-mechanical behavior of granite (sampling from Tibet Yulong copper mine) has been investigated under different frozen-thawed temperatures in laboratory. The temperature range was classified into 4 groups: -10℃~20℃, -20℃~20℃, -30℃~20℃ and -40℃~20℃. Mass loss rate, saturated water absorptivity, uniaxial compressive strength, elastic modulus, peak strain, poisson ratio and coefficient of freezing and thawing were measured. The lab results were used to evaluate the stability of the slope of the Yulong copper mine. And corresponding safety factors of the slope before and after frozen-thawed cycles were calculated and compared. The results show that the decrease of the temperature lower limit leads to larger mass loss rate, larger saturated water absorptivity of granite, and larger peak strain, but lower uniaxial compressive strength and lower elastic modulus. When the lower limit of temperature is below -30℃, the frost-resistance of granite becomes worse. The temperature range is an important factor for the physico-mechanical characteristics of the rock under freezing-thawing cyclic effect. This study is useful for analyzing slope stability under the influence of freeze-thaw.