Dynamic Response of Surrounding Rock and Supporting Structure of Deep Underground Cavern in Non-water-rich Strata Under Explosion Load

Abstract

The paper investigates the dynamic response characteristics of deep underground caverns and their supporting structures under explosive loading through numerical simulation. By systematically analyzing the displacement, stress, velocity, acceleration, strain, and plastic zones of underground caverns under different explosive conditions, the following conclusions are drawn: As the peak of explosive pressure increases, the peak velocity significantly increases, and the displacement of the crown settlement and floor heave also increases accordingly. Under explosive loading, the surrounding confinement pressure of the cavern exhibits significant compression and tensile damage, especially in the support area at the bottom of the cavern, which is more sensitive to failure. Therefore, additional reinforcement is required during the design phase. The explosive stress wave induces a dual plastic state in the cavern, including tensile and shear plasticity. As the stress wave propagates, the tensile plastic zone gradually expands, with the expansion rate slowing down over time. The medium elements near the blast hole mainly exhibit tensile-shear failure, while those further away from the blast hole predominantly experience tensile failure. This study provides an important basis for optimizing protective measures in deep underground engineering, particularly in the design of cavern supports and structural reinforcement.