Dynamic behavior of cement-mortar cavern reinforced by bars

• A numerical model consists of cavern, supports and their interaction is developed.
• Typical failure modes of bar reinforced cement-mortar cavern are identified.
• The critical bar spacing which controls the failure mode is defined.

This paper conducts a numerical study on the failure modes of aluminium bar reinforced cement-mortar cavern under blast loads. A simplified softening model is proposed to simulate the bond–slip behavior between the aluminium bar and the cement-mortar materials. Comparisons between the numerical results and the test ones demonstrate the accuracy of the proposed numerical model. According to the numerical simulation, three failure modes of the aluminium bar reinforced cement-mortar cavern are identified: (1) failure in reinforced zone, (2) failure in unreinforced zone, and (3) a combining mode of failure in reinforced and unreinforced zone. The results of the numerical simulations indicate that there exists a critical bar spacing, which controls these failure modes: the failure zone transits from the reinforced zone to the unreinforced one by decreasing the bar spacing. A parametric study is also conducted to give a better understanding of the dynamic responses of the aluminium bar reinforced cement-mortar cavern.