Freeze-thaw weathering of rock mass is mainly controlled by several factors

such as lithology

structure of rock mass

saturated water and temperature. In this study

the freezing and thawing strain tests were carried out on four kinds of fractured rock from the cold zone of Xinjiang. The strain processes of dry and saturated fractured rock were obtained under freezing and thawing conditions

respectively. It is found that the saturated fractured rock under eight strain stages

while the dry fractured rock experienced five strain stages. The swelling-shrinking ratio ? of saturated fractured rock was defined under the freezing and thawing action. Furthermore

the fitting relationships between the ratio? of different lithology and freezing-thawing cycles were gained. At the same time

the variation law of strain in the process of cyclic freezing and thawing was analyzed

which revealed that the maximum micro-strain of fractured rock at the frost heave stage increased with the increase of the cycle number. Besides

the freeze-thaw strain tests on jointed rockmass were conducted under different constant temperatures

and the fitting relationships between strain and different constant temperatures were obtained as well. Testing results demonstrate that the ratio ? increased with increasing the freezing and thawing cycle. Moreover

the variation degree of swelling-shrinkage rate was related to rock porosity characteristics. In addition

saturated jointed rockmass was highly sensitive to the temperature during the freezing and thawing process

and the damage was reflected as the thermal and frost heaving damage.