## 1 Introduction
[PERSON] et al. [28] studied the strength characteristics of frozen  
Figure 1: Yulong Copper Mine in Tibet, China. (**a**) Tibet Autonomous Region in Southwest China; (**b**) Satellite imagery of Yulong copper mine; (**c**) Rock slope in Yulong copper mine. limestone sandstone in different confining pressures under cyclic loading and unloading, and found that the peak strength increased under low confining pressures, while the peak strength 'weakened' under high confining pressures. Some scholars have conducted compression experiments on frozen rock specimens with cracks at low temperatures. [PERSON] et al. [29] studied the strength, deformation and crack evolution characteristics of frozen red sandstone with two ice-filled defects under different temperatures and sealing pressures. [PERSON] et al. [30] studied the influence of crack inclination angle, length, width, confining pressure and temperature on the mechanical properties of single and double crack rock mass under low-temperature conditions. They found that Poisson's ratio and elastic modulus were less affected by confining pressure under low-temperature conditions, and rock mass strength increased with the decrease in temperature. The inclination angle had the most significant effect on the strength of rock mass, followed by length and temperature. The above studies used red sandstones or similar materials to discuss the fracture mode and mechanical properties of frozen rock mass after compression. They considered the relevant engineering problems in the construction process of the artificial freezing method. The mechanical properties of the frozen fracture rock mass with high density which is encountered in the blasting construction of the cold region strip mine are not clear. Currently, relevant studies on frozen fracture rock mass mainly evaluate the compressive strength. In contrast, field sampling in cold regions and tensile strength tests of frozen fracture rock mass have not been involved. In particular, there has not been a comprehensive and systematic analysis of the influence of ice-filled crack space distribution on the tensile strength of frozen fracture rock mass and the failure process of wing crack propagation under load. At the same time, it is difficult to obtain the original rock in a high altitude cold region project. So, it would be of great value to find an effective numerical simulation method to analyze the mechanical properties of frozen rock mass. This study focused on the tensile strength of frozen fractured rock mass in high altitude cold regions. The aim of the study was to reveal the tensile characteristics and fracture mode of frozen fractured rock mass during the Brazilian splitting test process. The original rock sampling and processing were carried out from the Yulong Copper Mine in Tibet, China, to make artificial ice-filled crack marble specimens. The Brazilian splitting test of frozen rock mass was carried out. Firstly, the influence of ice-filled cracks with different angles on the strength and fracture mode of the frozen rock mass was investigated experimentally, and the initiation and propagation of wing cracks were recorded by a high-speed camera. Furthermore, the effects of the width and length of the ice-filled cracks on the tensile properties of rock mass were discussed by RFPA3D.