## 1 Introduction
showed that the quantity of gas extracted from a single borehole controlled by CO\({}_{2}\) fracturing increased by about fourtimes, and the outburst suppression effect was evident after comparing the gas desorption index of drilling cuttings within 20 m before and after blasting in the heading face [14]. Several scholars have conducted relevant physical experiments to study the mechanism of L-CO\({}_{2}\) phase change fracturing technology in coal rock. [PERSON] et al. placed L-CO\({}_{2}\) phase change blasting tubes within a core holder casing and subjected coal samples to dynamic impacts at different blasting pressures [15]. They performed field emission scanning electron microscope (FESEM) tests on the fragmented coal samples, revealing that CO\({}_{2}\) blasting generated a significant number of micron-scale tri-radial-wing fractures, greatly enhancing the connectivity of coal fractures. [PERSON] et al. conducted CO\({}_{2}\) blasting fracturing experiments on coal-like material samples with 400 mm edge lengths under various stress conditions using a triaxial load platform [16]. [PERSON] et al. performed CO\({}_{2}\) blasting fracturing experiments on coal samples at blasting pressures of 10 MPa to 25 MPa, indicating that continuously increasing blasting pressure reduces the fracture extension range while significantly increasing the crushed zone area, thus necessitating the identification of reasonable blasting pressures in engineering applications [17]. [PERSON] et al. theoretically analyzed and divided the L-CO\({}_{2}\) phase change fracturing process into two coupled processes: blasting-induced coal fractures and blasting-induced damage for eliminating stress concentration [18]. The aforementioned studies analyzed the impact of blasting pressure and in situ stress on the effect and mechanism of L-CO\({}_{2}\) phase change fracturing from the perspectives of coal micro-fracture and macro-damage. However, due to experimental constraints, they did not consider the synergistic effects of in situ stress and blasting load. [PERSON] et al. conducted numerical simulations using explicit dynamics analysis software ANSYS/LS-DYNA to study how coal seam physical parameters (in situ stress, gas pressure, and elastic modulus) and blasting parameters (blasting peak pressure and borehole diameter) affect fracturing outcomes, revealing that physical parameters have a minor influence on the scale of fracturing, while blasting parameters have a significant impact [19]. [PERSON] et al. constructed a FLAC numerical model to investigate the effects of energy release direction, coal rock mechanical properties, blasting parameters, in situ stress, and borehole parameters on phase change fracturing outcomes, concluding that coal rock compressive strength and cracking hole spacing are critical factors affecting fracturing effectiveness [20]. [PERSON] et al. accurately calibrated the dynamic constitutive model of coal rock (Holmquist-Johnson-Cook model, HJC model) through static and dynamic experiments, providing an in-depth analysis of the mechanisms of L-CO\({}_{2}\) blasting fracturing [21]. These studies systematically clarified the influence of various factors on the effectiveness of L-CO\({}_{2}\) phase change fracturing through numerical simulations, providing theoretical support for optimizing fracturing processes. However, the aforementioned numerical simulations overly simplified aspects such as the L-CO\({}_{2}\) phase change load form or coal rock mechanical constitutive relationships, and did not delve into the interactive effects of in situ stress parameters and blasting loads on fracturing outcomes. In summary, there remains a lack of numerical simulation methods that can accurately model the entire process of L-CO\({}_{2}\) phase change blasting fracturing in deep coal seams under high in situ stress. Based on the limitations of the aforementioned research, this paper systematically conducts numerical simulations of L-CO\({}_{2}\) phase change blasting fracturing in deep coal seams.