[19] further partitioned elongated cylindrical charges into a series of instantaneously detonated short charges, deriving vibration velocity formulas for arbitrary points using time-delayed superposition of detonation wave propagation. In experimental and field-testing research, advanced techniques such as dynamic caustics and ultra-dynamic strain measurement have been widely adopted. [PERSON] et al. [20] systematically investigated stress-strain fields in centrally initiated cylindrical charges and the evolution of local stress fields near blast-induced crack tips using dynamic caustics. Their study revealed significant principal stress differences across orientations and pronounced end effects. [PERSON] [21] conducted scaled model experiments to analyze stress wave superposition between adjacent boreholes. [PERSON] [22] used physical modeling to simulate blast-induced disturbances in underground tunnels, mapping surface strain distributions at various blast locations. [PERSON] [23] employed a high-speed camera-based digital image correlation system in dual-borehole blast tests, showing that peak stress at the midpoint between two charges reached 2.4-2.7 times that of single-hole blasting. [PERSON] et al. [24] developed an embedded strain bar system incorporating MEMS sensors and wireless transmission, enabling real-time monitoring of dynamic stress fields during construction of the Qingdao Jiaozhou Bay Tunnel. Their signal processing algorithm combining wavelet denoising with Kalman filtering improved the signal-to-noise ratios from 15 dB to 28 dB. [PERSON] [25] optimized field blast monitoring protocols to capture dynamic strain on tunnel primary lining (TSL) surfaces. [PERSON] et al. [26; 27; 28] performed in situ dynamic strain measurements on existing tunnel surfaces, quantitatively confirming strain amplitudes on blast-facing sides. In a numerical simulation, [PERSON] et al. [19] used 3D dynamic finite element software to model cylindrical charge blasting in infinite rock masses. By developing a quarter-symmetry finite element model, they systematically examined the effects of initiation positions on explosive energy transmission and stress field distribution. [PERSON] et al. [29] applied numerical simulation to analyze rock fragmentation under stress wave superposition from multi-source charge detonations, confirming that stress wave interactions from spherical charges align with theoretical rock-breaking mechanics. [PERSON] et al. [30] proposed a numerical analysis model for strip charge stress fields by integrating the Starfield superposition method with dynamic finite element analysis, providing a comprehensive understanding of the formation and evolution mechanisms of blast-induced stress fields under diverse initiation modes. In summary, despite substantial progress in studying stress fields from cylindrical charge blasting, three critical limitations remain:  
1. Methodological limitations: The widespread use of equivalent spherical charge models--which inherently omit S-wave generation--fails to reflect actual field conditions, where cylindrical charges produce both P- and S-waves. 2. Dynamic modeling oversights: Current superposition approaches for elongated charges, based on short-cylinder solutions often overlook two key factors: (a) axial pressure effects from instantaneous detonation of short cylindrical cavities, and (b) the evolution of rock mass damage in media treated as continuous, homogeneous materials. Validation constraints: Most existing measurements focus on surface particles, lacking in situ dynamic stress data from within the rock mass, which limits the verification of theoretical formulations models. To address these gaps, this paper builds on explosion stress wave propagation theory and [PERSON]'s short-cylinder solution [9], incorporating the axial pressure generated by the instantaneous detonation of short cylindrical cavities (Figure 1) and the effects of rock mass damage.