Hu Shuangping, Ye Wanjun, Zhang Xiaofeng, Hu Zhimin, Li Changqing
Chinese Journal of Underground Space and Engineering. 2020, 16(2): 406-411.
To explore the relationship between the uniaxial compression strength and the freezing temperature of the large size and rich water and egg gravel like frozen state,this paper took the water rich egg gravel sample of the liaison channel of the National University of Nanning and Qingchuan station as the research object,then produced the large size mold preparation sample,and carried out the single axis resistance to the sample through the GCTS test platform.The interaction relationship between the strength of the specimen and the freezing temperature was tested.The test results show that the compressive strength of the sample increases with the freezing temperature decrease,the bearing capacity of the sample increases continuously from 2.18 MPa to 3.1 MPa,and the strain of the test axis decreases with the freezing temperature decrease;under the freezing condition,the strength of the egg gravel test sample is mainly influenced by the strength of ice,the strength of the connection of the ice and gravel,and the content of the unfrozen water in the sample.In a certain range,the strength of the freezing temperature,the strength of the ice and gravel connection,the decrease of the content of the unfrozen water,the cohesive force and the internal friction angle increase slightly,and the gravel specimen will be frozen with the freezing temperature.The tensile strength of the specimen increases continuously,and the axial strain decreases with the freezing temperature decrease,from 7.4% to 3.2% when the maximum compressive strength is reached,indicating that the brittle ductility decreases with the decrease of the freezing temperature,and the failure of the specimen tends to brittle failure.
