Tensile Properties of Saturated and Dry Rocks at Ultra-low Temperatures

In this paper, a homemade ultra-low-temperature environment mechanical loading test device is used to carry out a Brazilian splitting test of stone under the action of ultra-low temperature (-90℃, -120℃, -165℃), to study the mechanical properties of saturated and dry granite and marble, and to reveal the mechanism of development of tensile damage and the evolution of internal energy of the rock under the action of coupling of temperature field and stress field. The results of the study show that the rock cracking is more complicated compared with normal temperature, in addition to the main crack of splitting damage, accompanied by complex secondary cracks, and the bottom of the water-saturated specimen will also appear in the delta damage. The tensile strength of saturated and dry rocks under the ultra-low temperature environment have different degrees of improvement, and the strength increase under saturated conditions is more significant. The purpose of this paper is to study the tensile and destructive properties of rocks under ultra-low temperatures, and the evolution of rock properties under the force-heat coupling obtained from the test can provide a reference for the rational design of cavern-type LNG storage tanks.