## 1 Introduction  
As economies grow and the demand for resources and energy continues to rise, deep underground engineering has become increasingly vital for mining, energy storage, and transportation infrastructure. However, these projects often face significant challenges, including intense rock dynamic hazards that frequently occur during construction, such as rockbursts. Notable cases of severe rockburst disasters have occurred in projects such as the Jinping II Hydropower Station tunnels (China), the Neelum-Jhelum TBM Tunnel (Pakistan), deep gold mines (South Africa), the Hongtoushan Copper Mine (China), and the Upper Silesian Coal Basin (Poland) [1, 2, 3, 4, 5, 6], underscoring the challenges faced in high-stress underground environments. These incidents not only pose a significant threat to the safety of workers but also lead to equipment damage and project delays. This disruption affects both project outcomes and social harmony. Rockbursts, a sudden and violent failure of rock, are typically classified into two types: strain-mode and slip-mode, depending on geological conditions and stress release mechanisms [6; 7]. The strain-mode rockburst occurs when intense stress disturbance causes rock to rapidly release stored energy, leading to dramatic cracking and material breaking away. Although researchers have made progress in predicting and managing rockburst hazards, the exact mechanisms and warning signs of strain-mode rockbursts under complex stress conditions remain unclear. In particular, further exploration is needed to clarify how acoustic emission parameters can effectively capture and reflect the evolution of a strain-mode rockburst. In recent years, scholars have conducted extensive research on rockburst disasters, yielding significant theoretical and experimental advancements. Studies in this field largely focus on laboratory experiments, field monitoring, numerical modeling, and theoretical analysis [8; 9; 10]. Among these approaches, laboratory simulations offer notable advantages, including precise control, high safety, accurate data collection, and shorter study durations [10]. These strengths make laboratory simulations particularly effective for investigating the mechanisms, identifying key influencing factors, and detecting early warning signs. For instance, [PERSON] et al. [11] conducted uniaxial loading tests, discussed the brittleness index and AE characteristics of dry and saturated granite samples, and revealed water's role in reducing rockburst tendency. [PERSON] et al. [12] performed uniaxial compression tests to investigate loading rate effects on rockburst proneness and concluded higher rates increase bursting liability through elastic strain energy release. Moreover, [PERSON] et al. [13] employed the biaxial Hopkinson pressure bar system to investigate sidewall rockburst mechanisms in D-shape tunnels and concluded that static stress and impact load interactions trigger rockburst events. [PERSON] et al. [13] utilized the biaxial Hopkinson pressure bar (BHPB) system to study the sidewall rockburst of a D-shape tunnel by applying various pre-stresses, including horizontal and vertical static stresses, to a sand prefabricated D-shape hole specimen, followed by impact loads. [PERSON] et al. [14] conducted true triaxial compression tests on pre-heated granite cubic samples containing a circular through-hole, and the micro camera was used to monitor and record the rockburst process in real time. [PERSON] and [PERSON] [15] tested tunnel models under compression to analyze fracture patterns and identified a sharp decrease in the seismic \"\(b\)-value\" as a precursor for predicting rockburst hazards. [PERSON] et al. [16] proposed the concept of \"stress concentration\" based on relevant data from a large number of engineering rockburst cases and established a new rockburst criterion that considered the stress-strength ratio and the stress gradient of the surrounding rock.