# Numerical Simulation of Seismic-Wave Propagation in Specific Layered Geological Structures
## 1 Introduction  
The propagation of seismic waves through geological structures represents a pivotal area of investigation in the comprehension and mitigation of seismic activity [1; 2]. Seismic-wave propagation correlates with geophysical structures [3; 4]. Analyzing stress-wave propagation is crucial in understanding mechanical properties [5; 6]. One of the most prevalent methodologies in the field of seismic-wave studies is the inversion of seismic waves [7; 8; 9]. This technique functions in a manner analogous to a geophysical X-ray, utilizing data derived from the Earth's surface to construct a comprehensive image of the underlying geological structures [10; 11]. Seismic-wave inversion has become a standard practice in the oil and gas industry for mapping the subterranean terrain, due to its high degree of accuracy [7; 12; 13]. In the field of seismic-wave inversion, numerical simulations have become an indispensable tool for advancing scientific understanding [14; 15; 16]. The simulations of seismic-wave propagation within the Earth provide an exemplar of the potential for earthquake-induced seismic activity, quantifying probable surface disruptions [17; 18; 19]. The incorporation of parameters that accurately reflect the characteristics of the medium of the Earth into seismic-wave simulations has the potential to enhance our theoretical understanding of these phenomena [14; 20]. These simulations are not just tools; they provide insight into the propagation of seismic waves, thereby improving the accuracy of seismic-wave inversion techniques [21; 22]. Notwithstanding the considerable advances made in thecomprehension of seismic-wave behavior through numerical simulations, there has been a paucity of studies that have investigated the propagation of seismic waves from the source. LS-DYNA is a finite-element analysis software widely used in the engineering sciences [23]. LS-DYNA software has a diverse range of applications in the simulation of explosive shock wave generation and propagation, as well as in the analysis of the dynamic response of materials [24]. The software has been utilized for the assessment of overpressure in steel tunnels subjected to external explosions and the modeling of shock wave effects [25; 26]. Furthermore, LS-DYNA has effectively captured the intricate interactions between shock and explosion waves and surrounding structures [27]. This is exemplified in the analysis of gas explosions within confined roadways and challenging geological settings [28]. Nevertheless, there is a paucity of LS-DYNA simulations of seismic-wave generation and propagation. This study introduces a new numerical simulation method for the study of seismic-wave propagation in geological structures. The energy released during these simulations is considered to be equivalent to that of a TNT explosion. For the first time, the TNT energy release process is used to simulate the generation of seismic waves during earthquakes, which is an innovation in our research approach. Furthermore, the simulated results are compared with actual seismic data from the 2012 Northeast China earthquake, verifying the model's effectiveness in predicting seismic-wave propagation in geological structures. To verify the model's applicability in various geological conditions, the simulation model is used to simulate seismic-wave propagation and stress distribution features in different geological settings, including water and layered geological structures. Subsequently, an equivalent blast response numerical simulation methodology is put forth for the examination of stress-wave propagation within a particular geological structure. The paper is structured as follows: Section 2 presents a seismic event condition located in northeast China. Section 3 presents a numerical simulation model and the simulation result of seismic-wave propagation in a geological structure. Section 4 presents the methodological extensions, with a particular focus on the explosion response in water and layered geological media.