Field test and theoretical analysis of a large underground arch structure subjected to buried explosion

Underground arch structures play a crucial role in protective engineering. However, with the advancement of military technology, buried explosions caused by earth penetrators have emerged as a significant threat to these structures. To investigate the dynamic response of underground arch structures subjected to buried explosions, a large arch structure was designed and constructed in a weathered basalt mountain, followed by field explosion tests. During these tests, various parameters such as pressure, velocity, acceleration, and displacement of the structure were recorded and analyzed. The test results demonstrate that conducting field explosion tests on a large arch structure facilitates the acquisition of detailed and comprehensive insights into the dynamic response of underground arch structures. When subjected to overhead explosions, the structure exhibited an overall response, with a noticeable local effect. The dynamic response of the arch was found to be significantly larger than that of the floor slab. Additionally, as TNT mass increased, the response of the structure became more intense, while its rebound ability weakened. The acceleration frequencies of the structure were primarily concentrated in the low-frequency ranges. Furthermore, the dynamic response of the structure was analyzed using a simplified load model and modified governing equations. The proposed theoretical analysis model effectively predicted the peak displacement of the arch. These research findings can serve as a valuable reference for the design of anti-explosion in large underground protective structures.