Experimental study on tensile strength of frozen expansive soils based on Brazilian splitting tests

The tensile strength of frozen soils plays an important role in geotechnical problems involving tensile failure. In order to study the tensile properties of frozen expansive soils, a series of Brazilian splitting tests (BST) are used to study the effects of loading mode, height to diameter ratio of samples, loading rate, temperature, dry density and water content on the force-displacement curve and tensile strength. The test results show that the frozen expansive soils exhibit typical brittle failure characteristics under different temperatures, dry densities and water contents. The tensile strength of the frozen expansive soils increases with the decrease of temperature. When the dry density of the sample is the maximum, the relationship between its tensile strength and temperature is linear. However, for the samples with dry density less than the maximum, the relationship between the tensile strength and the temperature within the test temperature range is more suitable to be expressed by an exponential function. The relationship between the tensile strength and the temperature of the frozen expansive soils can be described by a linear relationship with different water contents, and the lower the water content, the greater the increment of tensile strength caused by the decrease of unit temperature. The tensile strength of the frozen expansive soils increases with the increasing dry density and water content, and there is a good linear relationship between the tensile strength and the dry density and water content under various temperature conditions.