## 1 Introduction  
Coal, as a naturally discontinuous and heterogeneous geological material, exhibits an inherent anisotropic bedding structure due to prolonged geological sedimentation processes. Influenced by the dip of the coal seam and the surrounding rock stress field, coal is highly susceptible to the formation of random and disordered fractures, which complicate the initiation and propagation of cracks. During the underground mining process, various protective coal pillars are often left in place. However, as mining activities redistribute the stresses around the coal pillars, these pillars are subjected to long-term static loading from the overlying strata, leading to creep instability. Therefore, investigating the anisotropic mechanical behavior of coal rock under the influence of bedding and understanding the failure mechanisms of anisotropic coal rock under creep loading is of significant importance for the prevention, early warning, and safety management of coal mine disasters, ultimately contributing to ensuring safe coal mine operations. The influence of anisotropic bedding on the macroscopic mechanical properties of coal rock has been extensively studied in recent years. Research findings indicate that the failure characteristics of coal rock are significantly affected by both anisotropy and loading conditions. Through a series of uniaxial compression [1; 2; 3], triaxial compression [4; 5; 6; 7], and dynamic impact [6; 7; 8; 9] tests, scholars have observed that the bedding angle and peak strength characteristic curves of anisotropic coal rock typically exhibit a \"U\"-shaped or near \"U\"-shaped form. Furthermore, it has been noted that the directional distribution of the coal rock's internal microstructure leads to systematic variations in its mechanical properties [10]. Although the static and dynamic instantaneous strength characteristics of anisotropic coal rock have been extensively validated in previous studies, as a typical soft rock, coal exhibits significant time-dependent rheological properties. Under varying stress levels, coal rock demonstrates distinct creep deformation behaviors, prompting the widespread application of multistage creep loading tests to investigate the creep deformation characteristics of coal rock. [PERSON] and [PERSON] [11] performed numerical studies to reveal the scale effect of coal samples, and the results indicated macro failure in compression initiated by micro tensile fractures coalescing at mid-height and resulting in a wasting observed underground in over-stressed coal pillars. [PERSON] et al. [12] conducted experimental studies on the deformation and acoustic properties of extremely heterogeneous coal under incremental creep stress, noting that long-term coal creep results from multiple structural deformations, including particle dislocation, pore closure, matrix cracking, and clay mineral compaction. These structural changes in coal led to fluctuations in ultrasonic velocity and dynamic modulus. [PERSON] et al. [13] performed multistage and graded cyclic creep tests on intact coal rock, finding that the Burgers model could effectively predict the transient and secondary creep behaviors of intact coal rock. [PERSON] et al. [14] conducted triaxial multistage creep tests on coal rock with initial damage, and the results indicated that increased initial damage significantly reduced the creep time and long-term strength of the coal samples. While significant progress has been made in studying the creep deformation characteristics of coal rock, current research primarily focuses on exploring and predicting the axial average deformation evolution process of coal samples. There is limited research on the full-field strain evolution and crack propagation characteristics of anisotropic coal rock under creep loading.