# Dynamic Response and Rock Damage of Different Shapes of Cavities under Blasting Loads
## 1 Introduction
[8] conducted research on potential water inflow disasters caused by blasting vibrations during the excavation of submarine tunnels, combining experiments with numerical simulation and establishing a model for the evolution of seepage characteristics during the surrounding rock damage process. Despite numerous studies that have explored the dynamic response and damage issues of rock masses under blasting loads, there are still the following issues and controversies: (1) the dynamic response laws of cavities with different shapes under blasting loads are not clearly defined; (2) existing research is mostly focused on macroscopic response characteristics, lacking studies on the micro-damage mechanisms of cavities with different shapes. In response to the aforementioned issues and controversies, this paper aims to analyze the dynamic response patterns of cavities with different shapes under blasting loads, providing a theoretical basis for underground engineering construction. The study seeks to investigate the damage mechanisms and blast fragment size distributions of cavities with different shapes under blasting loads, explore the influence of cavity geological bodies on the size of blast fragments and rock mass damage characteristics, and reveal the mechanisms of rock mass damage and failure. The goal is to provide guidance for underground engineering design and construction to enhance project safety. Addressing the cavity structural conditions in mining geology, this study combines field tests with numerical simulations. Firstly, concrete model specimens with pre-set spherical, triangular, and rectangular holes (representing cavities with different shapes) were cast. A series of field experiments were designed and conducted to study the dynamic response and damage of cavities with different shapes under blasting loads, deeply investigating the relationship between cavity geological structures and blasting effects and providing important information on blast fragment size distributions for engineering practice and geological research. Subsequently, using the LS-DYNA finite element software, numerical simulation models of cavities with different shapes were established to simulate their dynamic responses and damage processes under blasting loads. By simulating the blasting processes of cavities with different shapes, the results can validate the field tests and further reveal how these geological structures affect rock fracturing and fragmentation and subsequently influence the block size distribution of blast products. This is of guiding significance for blasting construction safety in engineering projects. In the experiments, it is possible to predict the blasting effects under different geological structures, including block size distribution and degree of fragmentation, thereby providing predictions and references for actual projects. The experimental results can provide important data support for rock blasting and excavation in engineering projects, helping engineers make reasonable decisions and reduce uncertainty and risk. This study contributes to enriching the theory of rock mass dynamic response and damage under blasting loads, providing new perspectives and methods for subsequent research. (1) It offers a theoretical basis for underground engineering design and construction, enhancing project safety; (2) it aids in optimizing blasting parameters, reducing the impact of blasting vibrations on the surrounding environment; and (3) it provides technical support for China's underground engineering construction, fostering the sustainable development of the underground engineering industry. In summary, the research on the dynamic response and rock mass damage of caves with different shapes under blasting loads holds significant theoretical importance and practical application value.