Differences in the propagation laws of direct ground shock waves under various terrains and its effects on engineering site selection

• The several types of numerical models for rock masses under direct ground shock is established, based on the dynamic artificial boundary condition. • The geometric characteristics of the terrain have different effects on the peak stress and duration of the direct ground shock. • The attenuation characteristics of stress wave on high slopes was influenced by changes at the toe of slope, which can be divided into three stages. • Research indicates that the site selection for underground projects requires greater consideration of the load in the longitudinal direction (such as lateral incident loads, etc.). The construction of underground engineering is an effective approach to enhancing urban disaster prevention and mitigation capabilities. Proper site selection is essential to ensuring the structural safety of underground projects, and investigating the variation patterns of extreme environmental loads within potential site areas is a critical component of this process. Several types of numerical models for rock masses under direct ground shock are established, considering the effects of different terrains, explosion locations, and TNT equivalence on the propagation law of stress wave. We also explore the propagation process of stress waves in the high slope rock mass under the conditions of vertical or lateral incident loads, as well as the distribution of peak particle velocity (PPV) and peak particle acceleration (PPA) at the cross-sections of the computational model. Furthermore, the variations of peak stress, PPV, and PPA in different zones of the rock under the conditions of 5 types of TNT equivalence were discussed. Herein, the research results revealed that: 1) The geometric characteristics of the terrain have different effects on the peak stress and duration of the direct ground shock. 2) Under the same equivalent conditions, lateral incident loads are more likely to cause incipient damage in high slope rock. 3) The peak stress, PPV, and PPA all show an upward trend as the TNT equivalence increases. Therefore, site selection for underground engineering requires comprehensive consideration of the topographic characteristics of the target area, as well as the location and magnitude of the incident load.