Blast resistance of large underground rock caverns in hydraulic power stations

In order to fully realize the blast resistance of this kind of rock cavern, a great many 3D nonlinear finite element numerical simulations were implemented. Taking the damage of surrounding rock and concrete liner as evaluation criterion, the influence of embedded depth, rock property and lateral pressure coefficient on the blast resistance of the cavern was analyzed. The damaged plasticity model was adopted for the rock and concrete liner. Geometric nonlinear behaviors were also considered in every simulation. For this kind of high-wall cavern in a hydraulic power station, numerical results indicate that the blast resistance of the shallow cavern is weaker than that of the deep embedded cavern. The stiffer the surrounding rock, the stronger the blast resistance of the cavern. Numerical results also indicate that when the geo-stress lateral pressure coefficient λ is less than 1, the geo-stress lateral pressure coefficient affects weakly the blast resistance performance of the cavern. Once λ is greater than 1, the blast resistance of the cavern dramatically decreases with the increase of λ.