## 1 Introduction  
Influenced by the tectonic evolution of the Tianshan Mountains [1, 2], many faults exist in the TB mine in the Lihuhuanggou mining area, which is located at the foot of the Tianshan Mountains. The 501 working face studied in this paper exposed 28 faults during mining, including 5 penetrating faults, which caused frequent high-energy microseismic events when the working face was excavated. Triangle coal pillar is formed between the working face and the penetrating fault when the fault tends to penetrate the working face [3]. The triangular coal pillar is affected by the superposition of tectonic stress [4] and abutment stress [5] during the mining process of the working face. Its stress evolution is complex and the concentration is high, which induces dynamic disasters such as pillar burst [3; 6], and seriously restricts the safe production of the coal mine. For example, on 3 November 2011, when the 21,221 working face of the Qianqiu Coal Mine was excavated for the large F16 fault, rock burst occurred in the triangular coal pillar and caused 10 deaths [7]. On 1 April 2012, a rock burst occurred during the mining of the triangular coal pillar formed by f3110-1 and f3109-1 faults in the Chaoyang Coal Mine, resulting in 17 injuries or deaths [8]. Some scholars have conducted a thorough investigation into the mechanisms through which tectonic stress and fault activation trigger rock bursts during excavation of the working face towards the fault. [PERSON] et al. [9] and [PERSON] et al. [10] revealed that fault tectonic stress is an important factor in rock burst through stress monitoring data and numerical simulation; they found that the proximity of the fault correlates positively with tectonic stress. [PERSON] et al. [11] and [PERSON] et al. [12] investigated the influence of the roof structure on fault activation by establishing mechanical models for the fault and the roof. [PERSON] et al. [13] revealed that the excavation of the working face towards the fault induced the activation of the fault, releasing high-energy microseisms, which induced coal pillar burst with high static stress. [PERSON] et al. [14] demonstrated through numerical simulations that the maximum principal stress difference between the two sides of the fault is the main reason for fault shear-slip. [PERSON] et al. 's [15] analysis of the microseismic data reveals that fault activation occurs approximately 250-350 m ahead of the working face. By establishing numerical models, [PERSON] et al. [16] and [PERSON] et al. [17] found that dynamic stress from fault activation increases the rock burst hazard for the coal pillar. Furthermore, the energy and distance of fault microseisms are positively and negatively related to the stability of the coal seam, respectively. [PERSON] et al. [18] proposed a pre-mining evaluation method of fault stability based on fault orientation, in-situ stress and pore fluid pressure, which can evaluate the risk of rock burst. [PERSON] et al. [19] found that stress mutation would induce fault slip; they proposed a break-tip blast to control fault stress and thereby reduce the risk of rock burst. The aforementioned research underscores that the intricate interplay of tectonic static stress, structural alterations in the roof, and fault-activated dynamic stress collectively contribute to the occurrence of rock burst. The specific disturbance mechanisms and the extent of their influence are intimately tied to the unique characteristics of fault preservation [20; 21]. A penetrating fault is generally characterized by a throw that exceeds 5 to 20 m, with the maximum fault throw reaching hundreds of meters [22; 23; 24; 25]. Furthermore, it is observed that the tectonic stress on the fault is typically positively correlated with the magnitude of the fault throw [14; 26]. Therefore, fault protection coal pillars are strategically positioned within the working face to effectively isolate the influence of high tectonic stress, ensuring the safety of mining operations.